Back to Falcon Watch

Ask Jeff

ASK JEFF 1 - April 13, 2023

HELLO! HELLO! HELLO! It is so nice to be talking with all of you again. So much as happened to get us to this point in time. I’ll give you a brief synopsis of 2021, 2022 and to this date in 2023.

Before the 2021 Peregrine Falcon nesting season got its start, Ameren Missouri’s Portage de Sioux Energy center, where our camera used to be, decided to take down the nest box. You may remember the female (named Lizard when she was banded as a chick in Minnesota in 2006) that had been at that box since 2015 was very aggressive, striking me in the helmet with her feet many times as I removed her chicks for banding, and then put them back. She became so aggressive that she started attacking workers that weren’t even close to the nest. Out of safety for the workers, the box had to be removed.

Also in 2021, we had a successful nest at Ameren Missouri’s Meramec Energy Center, banding 2 chicks. Meramec is where the Meramec River meets the Mississippi River, about 25 miles downstream of St. Louis. The structure the box was on had to be removed after the chicks left the nest. For 2022 we tried placing a camera at a nest box in a slightly different location, but the pair never showed up. Sometimes a nest box can be placed in what we think is the perfect spot, but the Peregrines think otherwise.

Over the winter of 2022-2023 we placed a camera at Ameren Missouri’s Labadie Energy Center, which is on the Missouri River west of St. Louis by about 40 miles. We have had many successful Peregrine nests at Labadie. In 2022 though, the pair was on their territory, but didn’t produce any eggs. It’s hard to say why. I am happy to say that as of today, 11 April, the pair is incubating 2, maybe 3 eggs! We have not yet gotten footage of the male taking over incubation responsibilities from the female (or vice versa), so we can see how many eggs there are. We should soon know.

Neither the male or female are banded, hence we will never know their origins. However, there are subtle ways to tell the differences. The male has a very white chest, with the female having a more cream-colored breast with some dark flecks within the cream. Also, the female has more dark feathers on the sides of her face. Once you study the proportions of the box compared to the bird that’s incubating at the time, you will soon be able to tell how much bigger the female is compared to the male.

This pair, behaviorally speaking, has an interesting twist compared to all the Peregrine pairs I have known. Usually the female does the lion’s share of the incubating, with the male taking over 2-3 times a day, for only about an hour at a time. Our current male incubates just as much, if not more than the female during the day! I consulted a Peregrine banding colleague about this, and she told me it’s not that uncommon for the male to incubate much more than normal. I took a look at the box around 3 central today, and sure enough, the male was incubating. Several times over the last few days, I’ve watched him intently look at box ceiling as he incubates. I believe the female is standing on the box roof, and he hears her moving around up there. With how the camera had to be placed at this box, you cannot see the box roof.

I already have an “Ask Jeff” question to answer. Someone asked how the female gets fed while she is incubating. The male does most, if not all the hunting while the female incubates. He will place a prey item at a predetermined spot, fly to the box, the female leaves to obtain her meal, and the male incubates while she’s gone. Every time I have looked at the box in the early AM, the female is incubating. Seems she does all the nighttime incubating, and I’ll speculate that before the pair switches duties in the morning, the male has already left her a prey item at the “spot.”

It’s so nice to be writing again, and please bring on the questions. Until next week, take care everyone!


ASK JEFF 2 - April 26, 2023


I just took a look at the nest camera (2:30 p.m. central time), and as has been the case since the full clutch (4 eggs for this nest) was finished, the male is on the nest for the afternoon. I’ve yet to see the female-to-male switch, but I have seen the female incubating as late as 10 p.m. central time. As I mentioned in the first ASK JEFF, this male is much more an incubator than any other male I’ve known. For him to incubate so many hours in a row is rare. Usually, the female incubates 22-23 hours a day, with the male giving her a break here and there. There were no questions to answer over the last week, but that is typical as we move through the doldrums of incubation time. Since there are no questions to answer, I’ll give you all a quick history of Peregrines at this location.

There has been a nesting pair of Peregrines at Ameren Missouri’s Labadie Energy Center since about 1998. World Bird Sanctuary had this Center place a box on 1 of the 3 stacks about 10 years before that. When Peregrines decided to utilize the box, I was the lucky guy to climb to the box and retrieve the chicks during banding day. The nest box was at the 450-foot level of the stack, with no elevator, so I remember being quite worn out once I got to the box. Over the 10 years of weather before Peregrines used it, the box roof had rotted off, but the eggs, then chicks were as protected as they needed to be by the female. There were four healthy chicks, all about 25 days old. There was a winch at that level, so a crate was sent up to me, I put the chicks in, then the crate was lowered to the ground. The late, great Mike Cooke, longtime assistant director of WBS, and our Labadie contact, Tom See, did the banding. It took that team about 30 minutes to band the chicks, so what a view I got to take in during the wait. Labadie is on the Missouri River in northeastern Franklin County. I’m sure I could see at least 10 miles of our great namesake river. Of course, as I waited, the male and female Peregrine dive bombed me, but never really came too close. Seeing the river from my almost heavenly position and watching the Peregrines defend their nest…I was in heaven!

In what seemed too short a time span, I heard the winch turn on, so watched the crate full of young Peregrines slowly make its way to me. I placed the chicks back in their nest box, wished them a long and prosperous life, then started my climb to the ground.

Fast forward 25 years, and here we are, waiting for our eggs to hatch. Our pair should be incubating another 10 or so days, then we will hopefully see four chicks. Banding will take place about 22 days after hatching. At that age, the chicks will still be quite helpless, but be big enough to be able to tell the difference between males and females. The females are bigger enough than the males to get the next United States Geological Service band size up (males take size 6 and females size 7A). I’ll talk more about the bands just after I place them on the chicks. I don’t want to get hopes too far off the ground. There is a chance none of the eggs will hatch. There are many, many reasons eggs don’t hatch, but hopefully I won’t have to go over any of them when we see 4 bouncing chicks in the nest box.

There are several theories on why the females are larger than the males. The one I believe the most accurate is the female must produce up to 5 eggs, so a bigger body provides the proper amount of calcium and other nutrients for egg production, without so much a depletion to harm the female. I’ll talk with you all next week!


ASK JEFF 3 - May 2, 2023

Hello All! I have looked at the box several times this afternoon (May 1), and there seems to be no change in our status. To recap, both the male and female continue to diligently incubate the 4 eggs. We should be seeing chicks any time now. If anyone sees chicks when mom and dad switch incubation duties, please log into ASK JEFF and tell me the date and time you saw the chick(s). This information will allow me to set a date for banding the chicks. I will band the chicks when they are between 20 and 25 days old.

I received no questions through ASK JEFF over the last week. If any of you have questions about the nesting process or Peregrine Falcons in general, please ask me. I will be happy to explain things. Talk to you all next week!


ASK JEFF 4 - May 10, 2023

GOOD DAY EVERYONE! I have great news. As of today, May 9, we have at least 2 chicks! At about 10 am this morning, an Ameren Missouri employee sent me a picture from the webcam, showing the female sitting on the nest with half an eggshell next to her. Both mom and dad brooded enough today that it was hard to see if the other 2 eggs hatched. On bright days during the afternoon hours there’s enough shadow in the box where it’s difficult to see in, let alone if the parents are brooding (warming) the chicks. If they are not already there, hopefully this eve or tomorrow morning, and when the parents switch brooding duties, we will see a total of 4 chicks in the nest.

When a chick hatches from an egg, they use an egg tooth, which is at the end of their upper mandible, to break, or “pip” a line about halfway down the eggshell (if the narrow end of the egg were up). Once the end of the line they are pipping gets close the place they started, the egg basically falls open, exposing the chick; the moment of hatching. As the chick grows, the egg tooth wears off the end of the beak. On May 7 & 8, I banded 5 Peregrine chicks from 2 other nests in the St. Louis area. Two of the chicks still had their egg tooth, and the other 3 did not. Those chicks were between 23 and 28 days old.

For those that don’t know, when the parents have eggs, they incubate. When the eggs hatch, laying on the chicks is called brooding. When any chick hatches and during it’s first several days of life, it cannot produce enough body heat to sustain life. So, the parents brood, or keep chicks warm by keeping the youngsters covered with their belly and breast feathers. Once the chicks reach a certain size, they start to maintain their own body heat, and with the downy feathers covering their body, they don’t need the parents brooding them anymore. If you watch the chicks every day, you will probably see the time when the parents leave the box and only come to feed. On chilly days and before the chicks are about 20 days old, especially the female will come back to brood.

I like to band Peregrine chicks when they are between 20 and 25 days old. So, I will band our Labadie chicks on June 1, when they will be 23 days old. During this time frame the chicks are still quite helpless, with little if any strength in their feet, and still quite immobile. Yet, their legs and feet are fully developed, which helps me be accurate with the size bands I place on their legs. With most birds of prey, the female is larger than the male. With the world’s falcons, the size difference is usually so pronounced that the males get a band size smaller than the females.

I had a couple great questions over the week. Someone asked what would happen if the eggs never hatched. The Peregrine nesting cycle is governed by different hormones produced within internal glands. When the daylight starts to get longer in midwinter, that light stimulates the glands to produce these hormones. Then the parents go through the whole cycle, from courtship, to mating, to making the scrape that will keep the eggs in one spot at the nest site, to egg laying, to incubation, brooding, and finally pronounced food gathering to sustain the chicks. If the eggs don’t hatch, the parents will continue to incubate the eggs for several weeks past when they should have hatched. Eventually the body stops producing the hormones for the nesting season, and the parents leave the nest.

Another great question/observation was what the female does right before the eggs hatch. This person noticed the female raise her body above the eggs, and also she looked at the eggs a lot the day before they hatched. Just before hatching the chicks will start to make peeping noises and move around within the egg. The female definitely hears the peeps and probably feels the chicks moving within the eggs. The female will make peeping noises when she hears the chicks, which is said to help stimulate the chicks to pip and hatch. While I don’t know the exact reason the female raises her body over the eggs, I would speculate it’s to hear the chicks better, and maybe to allow the chicks to more easily escape the egg when it finally falls apart from the pipping.

Keep those questions coming, folks. Talk to you all next week!


ASK JEFF 5 - May 16, 2023

GOOD DAY EVERYONE! It took me until yesterday, May 15, to finally confirm we have four chicks. All the times I looked in on our new family only got me a pile of downy chicks, all too close together to decern individuals. Yesterday afternoon was warm enough, and also with the chicks six days old, they didn’t have to be piled on top of each other. In last week’s ASK JEFF, I wrote about brooding and why the parents must do this until the chicks are big enough to maintain their own body heat. Today, May 16, the chicks are seven days old. This morning was cool enough that I watched mom perform some seemingly half-hearted brooding, but remember, as the chicks get older they don’t need mom keeping them warm as much.

I also mentioned last week that we will band the chicks on June 1, when they are 23 days old. While banding day requires researchers to remove the chicks from the nest for banding, the effects of this disturbance is not long lasting. For those of us that have the privilege of watching the chicks grow on camera, we can see the chicks go back to their normal behaviors a few minutes after we place them back in the nest box. With this being the first season the camera is on this particular pair, and the fact neither parent is banded, I know of each parent about as much as everyone else watching. With most of the parents I have experienced on banding day, they fly overhead, do a lot of yelling, but don’t ever get too close to me as I extract the chicks. I have experienced two females that, to say the least, came a lot closer than others. If fact, they stuck my helmet with their feet many times as I extracted from, then the chicks back in the box. You can bet I will have plenty of personal protective equipment on when I approach the nesting box.

Over the past week I didn’t have any questions from viewers but did have several people tell me about the eggs hatching. Thank you very much for your alerts! I am already looking forward to writing to you next week. Keep those questions coming!


ASK JEFF 6 - May 23, 2023

HELLO EVERYONE! Even if I have said it a million times before, I’ll say it again. My goodness, do Peregrine chicks grow fast! Just a 4 days ago I looked at the box, and there didn’t seem to be chicks there. They were still small enough where they could pile together in the back, left corner, and you couldn’t see them. Today, Tuesday, May 23, our chicks are 15 days old, and big enough now that there’s no way they could all hide in that back left corner. I looked at them at about 4:10 a.m., and 2 were sleeping. The other 2 were pulling at prey feathers within the box and preening.

When birds are not feeding, drinking, bathing, sleeping or flying, they are preening. Preening is when birds groom their feathers. Feathers are important to birds in many ways. Of course, they are the reason birds can fly, but feathers also protect a bird from excessive heat, cold and water. When having to protect from such natural elements (and also from feather lice and mites), it’s no wonder birds take such great care of their feathers. Preening is an innate behavior, meaning every bird is hatched already knowing how to preen. During everyday activities, feathers can become mussed, allowing air to pass through them, rather than the feather pushing off and efficiently streaming through air. Mussed feathers also could allow body heat to escape and water to reach the skin. A bird will gently grab the base of a feather (where it grows from the body) with its beak and allow the feather to pass through its mostly closed beak, which in essence “put the feather back together.” I believe it’s safe to say a bird will preen each individual feather on its body at least once a day. Large groups of smaller feathers can be all grabbed at once by the beak, which helps preening be more efficient, yet those long, outer wing and tail feathers are preened individually. Also, almost all bird species in the world have a gland at the base of their tail that produces an oil. A bird will touch the gland with its beak and sometimes claws (birds use their claws to preen their head feathers), then preen its feathers. The oil helps keep feathers water resistant and helps preserve the life of each feather. If you watch the chicks for 15 or more minutes in a row, you will almost always see them preen.

I had some great questions over the week. The first is how large an area will a pair of falcons hunt? In essence, the place a pair of falcons hunt is called a territory. It’s hard to say how large a pair of Peregrine’s territory will be because the size is usually based on how available prey is. If an area has a lot of prey, the territories tend to be smaller because there’s enough prey to go around. Those pairs that have less prey available will defend a larger territory. Ameren’s Labadie Energy Center has several nest boxes where Peregrines could nest, but the pair would not let another pair move into one of the other boxes. There can be only 1 pair at this energy center. A few years ago in downtown St. Louis there were 3 pairs nesting, all within about a half mile of each other. From any one of these nests you could quite easily see the other two. I believe because of all the barge traffic that carries different kinds of grains, there is an overabundance of pigeons feeding on the grain that spills on top of the barge covers as they are being filled. Pigeons are one of the Peregrine’s favorite prey items (Peregrines prey on almost strictly other birds). I think the overabundance of pigeons, at least that year, explains why the pairs tolerated each other that close.

Another asked if our camera makes a noise or flashes a light, because they thought they saw the adults looking at the camera a lot. The camera does not flash a light, but will make a noise if the person that runs the camera pans in or out. We would never want to scare away the parents, so rest assured the camera is locked in its current position. Once chicks are hatched, it’s virtually impossible to scare away the parents, but especially early in the incubation period, parents are more apt to abandon because of a disturbance. As soon as we saw adult Peregrines at the box, we took all precautions. As always, thank you very much for the great questions. Just as a reminder, the chicks will be banded on June 1st. During the time it takes to band the chicks, the camera will be turned off. When it resumes coverage, each chick will have a band on its left and right leg. Next week’s ASK JEFF will be later in the week, but I’ll explain the bands and why we band the chicks. Take care everyone!

ASK JEFF 7 - June 6, 2023

HELLO EVERYONE! I am very happy to report that banding day, June 1, went perfectly. As I have told you many times before, placing bands on these incredible birds is one of my passions in life. Last Thursday was not a letdown, and in fact I witnessed the most spectacular dive, or stoop, by the adult male that I have ever seen in my life observing wild Peregrines. I’ll get to that later. First, the chicks. We have two definite females and one definite male. The fourth chick had a leg size that was in between the size 6 band that the males get and the size 7A that the females get. It is safer to place a band on a bird that is a little large in fit rather than a little small. So, I banded this particular chick with a size 7A. The chick in question was less developed in feather growth than the other three chicks. A very kind stenographer at Ameren Missouri’s Labadie Energy Center sent me a pictorial, with dates, of our Peregrine family that started when the first three eggs hatched. From the video the stenographer was able to isolate still pics and found that the fourth egg hatched about three days later than the other eggs. This is rare. Usually if the chicks are even one day old and there’s an unhatched egg or more, that egg/those eggs don’t hatch. Almost always, Peregrine eggs hatch within hours of each other. This phenomenon is thought to give all the chicks an equal opportunity of vying for food when mom or dad bring it to the nest. Eggs are laid about two days apart, but mom doesn’t start to consistently incubate them until the clutch, or full number of eggs she’ll lay, is finished. If the chicks hatched a day or two apart from each other, the two older chicks would be bigger, and could outmuscle the smaller, younger chicks for food, thus causing lower numbers of chicks fledging the nest. In this particular case, rest assured this younger chick is just as healthy as the other three, and many times I’ve watched this chick get its fair share of food. This chick is as large as the male chick, so for all of you taking a look after you read this, look for the chick that has shorter wing and tail feathers growing in. It should also have more down feathers on it than the other three, for at least another week.

We had a great question between the last ASK JEFF and this one. The question is, “What do we learn from banding the chicks?” First, having the chicks in hand allows us to see any evident problems with such a close visual inspection. If we wanted, we could also take blood, or swab the anus and/or the mouth and analyze the swabs. The most important reason we place bands on the chicks is to gain knowledge. When the chicks are standing now, you can see all of them have a black color field over blue color field band on their left leg. Within each color field are letters and numbers. On the right leg is a silver-colored band that has a sequence of numbers on it. All the numbers, color fields and letters on the bands are logged into the Bird Banding Lab’s national computer system. Anyone finding or seeing the bands can turn in the band’s numbers/letters and colors and find out where and when the bird was banded. I also log in the bands with the Midwest Peregrine Society and can find out even more information on a bird. I can also speak to the person that banded the bird for even more details. While we know so much about the Peregrine Falcon, there is still so much more to learn. Banding these chicks helps us continue to gain information that could one day come in handy if the species population starts to decline.

Earlier I told you about an incredible spectacle I witnessed, involving the adult male of our family. A little before 9 am on June 1st, I met Ameren Missouri employees in the Labadie Energy Center’s parking lot. We exchanged pleasantries as we walked toward the building, we would eventually band the chicks in. As we walked I noticed many Black Vultures flying low from the Missouri River’s direction, but with the day already warm, the vultures were starting to soar and quickly gain altitude. All 25 or so vultures were quickly soaring high over the large building that houses the turbines that produce the electricity we need for so much of our daily lives.

The vultures were also close to the center of the three stacks, which is the stack that has our Peregrine family on it. I quickly spotted the male Peregrine soaring with the vultures. He suddenly dove on one of the vultures that had gotten too close to that center stack. The vulture careened away from the male’s attack, and the male broke off its attack quickly. The male Peregrine made his point; “If you get too close to my chicks, I will attack you.” The group of vultures soared off to the south. The male continued to soar, and in less than a minute was at least 300 feet above the top of the stacks, which are 750 from the ground.

Suddenly the male folded the ends of his wings close to his body and started a steep dive toward the Missouri River, which is several hundred yards to the north of the energy center. I believe he had spotted a prey bird crossing the river, and from his high point of attack, thought he could get to and catch the bird before it made it to the trees along the river. This is how Peregrines hunt; from a high vantage point above a large expanse of water, forests or fields, waiting for a bird to fly far enough from cover to give the Peregrine a chance to catch it. Our adult male became a feathers and flesh bullet, speeding faster and faster toward the ground. From the six or so seconds it took from the start of his dive to where he disappeared from my view, I watched in pure astonishment! It was one of the most awesome six second snapshots of my life. From my estimate of his distance above the point he disappeared from my gaze (950 feet), compared to the time it took him from start of dive to point of disappearance (6 seconds), he was diving at least 108 miles per hour. I believe my heart rate was 108 beats per minute just before he disappeared. Seeing a wild animal, without the aid of an engine, moving so fast, is one of the many reasons I chose to study this fastest of all the world’s creatures. I’ll never forget what I saw on June 1st, 2023.

ASK JEFF 8 - June 11, 2023

HELLO EVERYONE! Today is Sunday, June 11. Today 3 of our chicks are 34 days old and 1 is 31 days old. Currently it is easy to tell which chick is the youngest. This chick has much more down on its body than the other 3. As the next 7 days progress the chicks will continue to lose the white down, so it will be a little harder to distinguish between chicks next Sunday. By next Sunday, don’t be surprised if a chick or 2 have flown from the box, or fledged. At 40ish days, the oldest chicks may decide to try flight for the first time. Also, there is enough room for the chicks to jump to the grating in front of the box, so there’s a chance they could be running around on the grating.

Today I’ve been watching the chicks on and off all day. Around 4:15 p.m. central I could see one of the older chicks going through the motions of eating something. At the same time, I watched a second chick going through these same motions. These two chicks put their heads down to their feet, then pulled upward with their beaks. The box, especially during afternoons and on cloudy days gets shadowy, so especially if a chick is in the back of the box, it’s hard to see exactly what it’s doing. Eventually the second chick mentioned pulled upward with its beak, and it lost grip with its feet. Part of a wing from a prey bird suddenly was in its beak. With essentially no meat on the outer wing, the chick just dropped the partial wing to the bottom of the box, which is where there are lots of partial wings and lower legs from the prey the parents bring to the box. When any bird of prey with strong feet eats, it grips the prey item with its strong feet, and at the same time, has the prey pinned to the ground, a tree branch, or in this case, the bottom of the box. With our chicks, the weight of the falcon standing on the prey, combined with the grip of its feet, keeps the prey in one spot and makes it easy for the falcon to tear small, bite sized pieces from the prey.

The first chick I mentioned continued to pull and tug at its feet, telling me it had something more substantial under its feet. Finally, the chick performing this behavior moved, lifting the item from its feet to its beak, and bringing it more forward in the box. I could now see the chick had in its beak the full body of a red-winged blackbird. This tells me that at least sometimes now, the parents are bringing full prey items to the box and just leaving the item, instead of staying and tearing the prey to feed to the chicks. All the chicks, even the younger one, have enough strength in their feet, and beak strength, too, to feed themselves.

Especially the three oldest chicks are spending more time perched on the front edge of the box, telling us they are getting better balance. At 5:00 p.m., I watched two of the three oldest chicks dozing while standing upright. Each of the two looked headless, as they had their head tucked under a wing on their back. This is another great indication of better balance. Even the youngest chick doesn’t waddle around the box on its whole feet anymore. It also walks confidently on the bottoms of its toes. The part of the foot that has a band on it is called the tarsus. Yes, that’s part of the foot, rather than the lower leg. The lower foot has 4 toes, so birds walk around on their toes all the time.

Over the last week there were no questions to ponder. Remember on our falcon cam website you can write questions you may have about our falcon family. I will write to you nest week.

ASK JEFF 9 - June 22, 2023


Good Day everyone! SUCCESS! The kids survived their stay in the nest box, and we all got to see our falcon family leave or fledge. I write to you on June 22. The last chick left the box June 21. The first 3 eggs hatched the eve of May 8, and that 4th egg hatched the eve of May 11. If my math is correct, we got to watch for 45 days, which is exactly the average time it takes a Peregrine chick from hatching to fledging. I’m sure you all have your favorite moments during those 45 days. As always, my favorite moment was banding day, which was when 3 of the chicks were 23 days old and the youngest was 20 days old.

I wish I could describe to you the feeling I get putting my hands on a bird that will dive at speeds well over 200 miles per hour and may move 5,000 or more miles in just its first year of life. My fleeting time with them gets permanently lodged in my long-term memory, and I can only tell you it gives me the greatest of pleasure bringing that few moments to the surface now and again.

I said “success” in that first sentence above, but I must be careful with that word when it comes to our family, and the world’s fledgling birds in any given year. Nature governs a bird’s time and circumstances on this earth, and nature is seemingly unkind. Sixty to 80% of all the birds hatched this year will die before they are 1 year old. There are literally millions of ways a bird can perish, but a few of the more prominent ones with Peregrines are:

  1. The first flight or two a Peregrine takes are at best clumsy. More times than not they go to the ground, where they become vulnerable to many other predators.
  2. Many Peregrine chicks just end up starving to death. The parents eventually stop caring for the chicks, and in fact will chase them from the territory they grew up in. When what you catch for survival (other birds in flight) is so agile, some Peregrine chicks just don’t become efficient at it before it’s too late.
  3. Humans and our modifications of the natural environment don’t help matters. Peregrines get hit by cars, fly into glass buildings and power lines and succumb to poisons we put out to kill pest birds, like pigeons and starlings.

Yes, it is a hard world for a Peregrine to survive in, but there are thousands of success stories, too. Those successes are of course those Peregrines that survive to breeding age and produce as many as 5 chicks a year for 15 or so years of their lives. Also, we humans help the Peregrine by the research we continue to do to keep the naturel environment as clean and toxin free as possible. Through past research we found out the insecticide DDT was slowly, but surely limiting wild Peregrine numbers to the point of them becoming endangered. We corrected our ways by stopping the spraying of it in the U.S., and releasing Peregrine chicks hatched in captivity to the wild to bolster their numbers. Peregrines were taken off the Federal endangered list in 1998 because of human efforts. The bands I place on the chick feet help with research. When/if those bands are seen again, it helps we ornithologists figure out movement and breeding patterns that could one day bring to light better ways to manage our environmental modifications to help keep wild Peregrines safe.

I want to answer one final ASK JEFF question. Several of you asked why one of the chicks had such yellow legs/feet, compared to the more normal creamy color the other 3 have. After consulting with two well versed, raptor vets, the answer is, “Not sure.” One of the vets suggested genetic variation. I did comment on how bright yellow the male legs and feet are. Maybe this particular chick got its father’s genetics for extra bright leg/foot color.

Before signing off until next season, I want to thank Ameren Missouri for providing the camera and nest box, so our Peregrines continue to have a place to nest, and so we can look in on such an incredible phenomenon. Second, I want to thank the Missouri Department of Conservation for their hand in bringing us the live camera, and for all their work preserving habitat for thousands of life forms. Finally, I must thank all of you. Your questions help me bring to light everything about a Peregrine’s life cycle. I think Baba Dioum, the Senegalese conservationist, said it best when he said, “In the end we will conserve only what we love, love only what we understand, and understand only what we are taught.” This glimpse into part of a Peregrine’s life teaches us so many things, which I know will make us continually want to help them and keep our environment healthy for all living things. Take Care Everyone! Already can’t wait to write to you next year.


#11 - June 29 - Season Finale

Hi Folks! Seems it’s been forever since I last wrote, and my only excuse was a great vacation. In case anyone hasn’t noticed, our kids have “flown the coup,” “disappeared into the wild blue yonder,” and “headed for greener pastures.” On Tuesday, June 22, we closed down the web camera. While my quotes above may lead you to believe the kids are not even in the area of the box any longer, trust that they still are. The Sioux Energy Center is loud because of all the machinery needed to produce the electricity we need, but I would guess you can still here the kids yelling their hunger scream, especially when they see one of the parents fly by with prey. Our kiddos are flying very well now, but still don’t have the flight skills to catch another bird in the air. Mom and dad will continue to provide them with prey for another 2-3 weeks.

Today, June 24, our juveniles are 57 days old. You probably noticed how different the juvenile plumage color is from the adult color. Juvenile, or hatch-year Peregrines, will keep this color until about next March, when one would start to see some slate blue flight, upper wing contour and tail feathers growing in. By the end of summer 2022, the juveniles will have most of their adult color plumage, and then have complete adult color the following summer. The color change doesn’t seem to signify to other adult Peregrines that the bird they are looking at is fully ready for breeding, since some 2021 hatched Peregrines will produce chicks in 2022. Most, however, will start producing chicks in 2023.

Let’s get to the final set of questions. Someone asked about nest box maintenance and change-out. Your question couldn’t be timed more perfectly. In late August, we will remove the current box and put up a brand new one. Every time I visit the box, I assess its structural integrity. This box was placed in its position in February 2012. Although built with pressure-treated lumber, my last assessment gave the box a D grade, so it, along with the camera, will be replaced. We are working on the change-out date right now. Also, about every three years, I replace the pea gravel in the box. Because of all the defecation, feather dander and prey parts, the gravel will get “clogged” and not let water drain as it should. Eggs or chicks that sit in a puddle are sure not to survive. Good gravel is a must.

Another asked where the Peregrines roost and whether or not Peregrines can be nocturnal. Unless the female must incubate eggs or brood young chicks in the nest box, she and the male roost, or spend the night somewhere within the energy center. They probably roost in a place (under an awning?) where it would be hard to be attacked by a Great Horned Owl, and of course far enough off the ground so a raccoon couldn’t prey on them.

The second part of the question is interesting; can they be nocturnal or hunt at night? Before humans invented electricity and artificial light, the answer was probably no. From personal observations with the birds World Bird Sanctuary use for education, I know even diurnal raptors (hawks, eagles, kites, falcons) can see much better than humans at night. I’ve known individuals of all types mentioned that are able to fly to and land perfectly on perches when their human caregiver (that would be me) could not see the perch they landed on because “it was too dark.” With all of the artificial light big cities put out, many observers have watched Peregrines hunting well into the night, preying on night hawks (look in your bird books…they’re not really hawks), big insects flying around lights and even bats. During the spring and fall migration, many bird species fly at night to cut down the likelihood of a diurnal raptor preying on them. If these birds fly too close to cities, their risk of being captured by a Peregrine increases dramatically. Remember, Peregrines dive on their prey at speeds well in excess of 200 mph, so flying after dark, even with extraneous light, would seem to be very risky. They hunt with no issues.

We have come to the end of Ameren Missouri’s Portage de Sioux Energy Center, Peregrine Cam Season 10. I’m so happy to say the season was very successful, with three kids raised and fledged. Our seemingly old male and female proved wrong my fear of no fertile eggs. Nature will probably take its course and replace one or both parents sooner than later, but time, and a new camera, will tell. As much as I would like to see the same parents next year, I would be just as happy to see a new mate, or even a new pair. To me the most important thing is we have a pair to continue to produce chicks that will ultimately keep the Peregrine population strong.

I can’t tell you how great it is to write to you about our pair, their kids, Peregrines in general and to answer your questions. You always ask questions that make me think. Those questions help me remember past experiences, and good or bad, remembering those experiences makes me a happier person. I’m already looking forward to watching the next year’s events and writing to all of you. Have a great rest of 2021!

#10 - June 9 

Hello everyone! I write to you on June 9 at about 4 o'clock in the afternoon. The chicks are 42 days old today. I just took a look at the box, and two kids were on top of it. One was lying down and the other was perched on the north edge of the box, gazing off to the north. The third chick, if you can even call them chicks anymore, was nowhere to be seen. A few minutes ago I spoke to the person that manages the camera, and he has seen one of the chicks running around on the I-beams that the box sits on or is near. About 5 years back all four chicks did the I-beams, but would come running back to the box when mom brought in prey. If the third chick is close by, anyone lucky enough to be watching as mom brings food to the box would probably see the third chick suddenly jump into the picture, as it is probably as hungry as the other two.

The third chick could have also fledged, as we are very close to the average time (45-55 days old) the chicks leave the nest on their first flights, which leads to our first two questions; how high is the box off the ground, and what happens to the chicks on their first jump into the wild blue? The box is 167 feet from the ground. The height helps when the kids take their first flights. The chicks are old enough now that if they jumped on their own or were blown off the top of the box, they would not plummet to the ground. They would fly, at least well enough to have somewhat of a controlled landing on the ground or a nearby rooftop. Peregrine youngsters, with their overly long wings, are clumsy flyers at first. As mentioned, they may go all the way to the ground, but the motivation of hunger and seeing their parents, which they know means food, will stimulate them into flying to higher perches during subsequent flights. The fledging period is the riskiest part of a Peregrine’s life, since being on the ground makes them vulnerable to more predators. Mom and dad will continue to defend them from aerial predators, since those predators have to invade the Peregrine parent’s territorial space to get to the kids, and that act makes them quite visible to the parents. A mammalian predator may not be seen and could attack the grounded kid without either of the parents knowing. FYI, if a youngster is found on the ground by a plant worker, the worker can catch it and if the bird seems fine physically, the worker will take the kid to a higher place, usually on the smokestack.

The last question is, “Do the kids stay close to each other after they start to fly?” The short answer is, “Usually.” The kids learn quite quickly that a parent will feed the first kid they see, so staying close means the kids have a better chance for food. I explained in ASK JEFF NUMBER 9 how the parents help to train the kids on catching prey. As the kids fly better and better, the parents will just give the first fledgling that flies to them the prey item, and that exchange almost always happens in the air. If they see the exchange, the other fledglings may chase the kid that got the food. Yes, there’s definitely fighting over food in the fledgling Peregrine world. When there’s no food in the scenario, the kids will chase, dive on and clasp feet with each other. While they seem to do this for the fun of it, it’s probably nature’s way of teaching the kids the fighting skills they will need to eventually catch their own prey while in flight. If/when the youngsters start to catch their own prey, they eventually are either driven off by the parents or fly off on their own to start a solitary life for the next 8 to 22 months. Less than year-old Peregrines have been known to produce chicks, but usually around 22 months is when they start their own or become part of the territory, accept a mate and produce chicks.

There’s a good chance over the next week our juvenile Peregrines will fly away from the box and probably never return to it. If this happens, I’ll write one more, 2021 farewell ASK JEFF. Please continue to write your questions, though. I’ll write to you next week!

#9 - June 8

Hello everyone! I just took a peek at the kids. They are 37 days old today. WOW! They now look way less like Peregrine chicks and much more like juvenile Peregrine Falcons. All were perched on the front lip of the next box, dozing now and then during the warmth of the day. In between siestas they were preening, or taking care of their feathers. Unless they are migrating long distances all of our world’s birds preen more during waking hours than they do anything else. Feathers are quite the incredible “outer garment,” if you will. They keep birds warm, cool, dry and are the reason birds can fly. Even penguins and other water birds rarely have water touch their skin because of how well their feathers protect them. As great as they are at protecting and allowing birds to fly, feathers need constant care by their owners. Birds have an oil gland that protrudes from the base of their tails. When birds are nosing around near their tails, they are stimulating the oil gland to exude oil, which they spread on their feathers with their beaks. This oil makes the feathers almost waterproof and certainly water resistant. The oil also helps the feathers protect their owners for many months and even years. Adult Peregrines complete a full flight feather and tail feather molt every three years. They lose, or molt especially flight feathers in a synchronized manor. For example, they will molt number seven primary (outer wing feather) on both wings at the same time, so flapping flight stays in synch.
Let’s get to your questions. I have two great ones. First question is - please explain the process in which falcons learn to fly. Birds that can fly are hatched knowing how. Flight is an innate ability. Learning how to fly well is another story. As you might imagine, Peregrine Falcon flight takes even more coordination than most other birds because of how fast they can fly and that they catch other flying birds while both prey and predator are on the wing. I’ve been able to watch many juvenile Peregrines learn to fly well, and when they first start out, they are clumsy. Usually, their first flight takes them to the ground; maybe the second flight too. After that, they learn how to control speed and lift and can at least land on perches more efficiently.

This is where the second question comes in - explain the process in which the falcons learn to hunt. Birds don’t fly to feel free. The “feel free” thing is what humans add to the scenario. For all bird behaviors, there’s always a motivation. For Peregrine flight, their first motivation is probably hunger. When they see mom or dad bringing prey to the nest, they will try to fly away from the nest to get the prey before one of their siblings can. The parents will start to drop the prey from well above the ground, probably to make the kids have to catch it themselves. The parents will then start to bring in prey that’s still alive, so the kids may have to catch something that can still move, and certainly will have to kill it if they catch it. With all this going on, the kids are developing better and better flight skills. The parent training continues for 3-4 weeks, and then the kids start to fly at prey birds on their own. At about this point the parents stop bringing prey in, and will even chase the kids out of the parent’s territory. Those kids that successfully catch prey are the ones that survive and have the best chance of living long enough to find a mate and produce their own chicks.

Our kids have about another two weeks before they leave the nest box. I hope everyone soaks up the great viewing as much as possible. I’ll write to you all next week.

#8 - May 27

Hello all! On Tuesday, our chicks turned 28 days old. Now it’s quite easy to see their flight feathers coming in through the down. The flight feathers are the wing and tail feathers. When I banded them a week ago today, the tail/wing feathers were about a half inch long. Soon we will be able to see the down on the chest and back replaced by the contour feathers. As you might guess, contour feathers grow from the body and all grow to curve just the right way as to hug the body contours. This “hugging” helps with waterproofing, insulation and aerodynamics.

I’m going to get right to the questions. I had several over the week, and all are good questions. Someone asked if the chicks were healthy when I had them in my hands. While we didn’t do any bloodwork or official physicals, I’ve had enough healthy Peregrine chicks in my hands over the years to know our three are healthy and well fed. Rest assured, if I thought any were not healthy, I would have brought them to the WBS Wildlife Hospital so our great team could assess further and prescribe the right treatment.  I would have gotten the chick(s) right back to the nest quickly, and the parents would have continued to feed and raise them. It’s a falsity that birds will reject their chicks if handled by humans. Most of the world’s birds have a poor sense of smell.

Another great question was what percentage of our chicks will survive to adulthood. It’s safe to say that 60%-80% of all birds hatched in the world this year will die before they are a year old. It’s hard to survive in nature. There are many hundreds, if not thousands of scenarios that could take the lives of 2021 hatched chicks. Human activity probably makes the odds even worse, but there’s human activity that has helped Peregrines in particular. WBS was one of many hundreds of organizations that released captive-hatched chicks to the wild, especially when the Peregrine was federally endangered from 1972 to 1998. Our efforts helped bring back the Peregrine as a breeding species in Missouri, with the first wild chick in over 80 years hatched on the downtown St. Louis AT&T building. That chick was hatched in May 1991 and it had parents that WBS had released to the wild a few years before. Currently the greater St. Louis area has about nine pairs of nesting Peregrines, including nests at Ameren Missouri’s Labadie, Rush Island and Meramec Energy Centers. The more Peregrines there are successfully nesting, the better chance the species will continue to survive and thrive, despite the percentages mentioned above.

“What happened to the eggs that didn’t hatch with our pair on camera?” From where I write, all I have to do is turn my head a little to the left and my eyes fall on those eggs. There was only liquid in those 2 eggs, so I placed a small hole at the narrow end of each egg and shook the liquid out.  Even if there had been partially formed chicks in the eggs, so much bacteria takes over once an egg dies that makes it impossible to find a cause for not hatching. WBS has the proper federal permits to use eggs and other bird parts for our educational programs. Inquisitive children, of all ages I might add, will eventually get to hold those eggs.

“How many times a day do the parents come to the nest now?”  Because the chicks are producing their own body heat and especially with the warm temperatures, mom does not have to brood, or help keep them warm anymore. The parents come to the nest to feed the chicks, which happens 3-5 times a day, and that’s about it. Mom has a high perch that puts her about 150 yards above and away from the nest box.  It’s the perfect place to keep a watchful eye on the box. If any predatory bird happens to get too close, you can bet she will dive on it and strike it with her feet, just like she did so many times to my helmet when I took the chicks for banding. She’s a great, protective mom!

Finally, two days ago someone took a screenshot of mom in the box, sometime mid-morning. This person described her behavior as pacing within the box, with her beak agape. From the screen shot I believe mom was taking advantage of the shade the box provides. With the screenshot, I noticed the chicks also had their beaks agape. Birds pant to keep themselves cool. They do not have sweat glands on their bodies. I’d guess all could imagine the feathers being wet from beneath and how that wouldn’t work with such a body covering. Panting rushes air across moist mouth and throat parts, and as the moisture evaporates it cools the blood vessels near the throat, and that cooler blood continues to circulate and helps keep the body cooler. During the morning hours the sun shines right into the box. We intentionally positioned the box facing northeast. The chicks need the sun to help with vitamin D production, yet as the day gets warmer and the sun seemingly moves to the west, the box becomes a shady spot to help keep the chicks cool; and mom sometimes, too.

Gosh! You all rock with those great questions. Thanks for watching and writing, and I am already looking forward to next week’s ASK JEFF.

#7 - May 20

Hi Folks! Yesterday morning, 19 May, was banding morning, and I am happy to report we have 3 girls, and all were healthy, well fed chicks. I placed a United States Geological Service (USGS) band on one of their legs, and on the other I placed an auxiliary band, which has 2 colored fields with white numbers/letters in each field. Both bands are aluminum, which is light weight, but sturdy. The USGS band has small numbers on it; much too small to see from any more than a foot away. However, the auxiliary band’s letters/numbers can be seen from a hundred or more yards away with the use of binoculars or a spotting scope. The auxiliary band makes it possible to gather information on a bird that’s alive and well in the wild. For instance, our female falcon has a black color field over a green color field auxiliary band, with a D in the black field and a 53 in the green field. This band was placed on her leg in June 2006 while she was with her nest mates in a cliff nest in a state park in Minnesota. At the end of this banding season, I will register all the peregrine chicks I banded with the Midwest Peregrine Society, the organization I get the auxiliary bands from. Then anyone that belongs to that organization can go to their website, type in the band numbers/letters/color fields they may have seen on a wild bird, and presto! You immediately get the information on that bird. Later this year this same information will be given to the Bird Banding Lab. Anyone can go to that website and enter band numbers/letters, and you will receive a certificate with information about the bird that has or had that band.

While I was at the front of the nest box, mom falcon struck my helmet many, many times as she flew by. Of course, she perceived me as a threat to her chicks, and the strikes were her way of trying to drive me away. She is such an impressive bird! Even as she pummeled me, it did not diminish in the least my respect and admiration for her and her species. While common today, mid last century the Peregrine was placed in peril because of the pesticide DDT. Over several decades, hundreds of thousands of tons of this pesticide was sprayed on our crops to kill insects that ate the plants. In the late 1960’s, we found out through scientific research that the pesticide got into the peregrines through the birds they ate and caused eggs with shells so thin the female would crush the eggs just trying to incubate them. DDT also brought other species, like the Bald Eagle and Osprey, to the brink of extinction before the pesticide was banned from use in the U.S. in 1972. All of those species were placed on the federal endangered species list the same year. Through the work of many organizations, including World Bird Sanctuary and Missouri Dept of Conservation, the Peregrine was taken off the endangered species list in 1998. Over the last 20 years, Ameren Missouri has placed nest boxes at 4 of their energy centers, and today all 4 have nesting pairs of Peregrines!

The chicks were removed from the nest and taken to an air conditioned room for banding. From time of removal to the time I placed them back in the nest box was about 45 minutes. Because of mom’s attacks I was efficient when putting them back, but still took a few seconds to wish the chicks luck in all their future endeavors.

There was only one question to answer from the previous week, and it was the perfect question for the day. “When will the chicks leave the nest?” Today they are 21 days old, and they will make their maiden flights when they are 45-50 days old. Enjoy the kids while you can. I look forward to writing to you next week.

#6 - May 14

Hello Everyone!  I am writing to you on the afternoon of 14 May. The chicks are 16 days old today and are growing rapidly. We will be banding them the morning of 19 May, when they will be 21 days old. At that age I will be able to tell the difference between males and females by size, which is quite important when placing the bands on their legs. The females are so much larger than the males that they get a larger size band.

You have probably already noticed that mom falcon isn’t spending as much time in the box. When the chicks get to about 10 days of age their bodies are big enough to produce their own body heat, therefore they can keep themselves warm without mom having to brood them. We have been having chilly nights over the last 5 or so days. Mom probably broods them at night, but during the days she can leave the nest. Rest assured she is very close by, in case a predatory bird comes too close to the nest.

A couple of you asked about predators of Peregrine falcons. Both Bald and Golden Eagles will prey on the chicks. Great Horned Owls will also prey on the chicks, and even will prey on the mom as she incubates or broods at night. Peregrines like to nest in high places, which is to lessen the chance that a mammalian predator can get to the nest. If the parents see even an eagle coming toward the nest, they will both attack it. Yes, the eagles are much larger, but the Peregrines are the fastest of the world’s creatures, with a top recorded speed of 261 MPH. They will dive at any predatory bird from above and strike the bird with their feet as they pass by. Even eagles understand they could be badly injured by the parents, and they will steer clear of the nest.

Another asked how many broods, or groups of chicks Peregrines will have in a year. Because they have to put so much effort and time into raising chicks, they raise only 1 family per year. They may have as many as 5 chicks per year, and are of breeding age from about 3 years of age well into their teens. They may have only 1 brood per year, but can have many years of broods.

A couple of others asked if Peregrines attack anything they consider a threat, how do I get so close to the nest? Rest assured, especially the mom will hit my hardhat many times during the few seconds it takes me to get to the nest, place the chicks in a crate and leave. I also have a heavy jacket on and safety glasses. Even with all this personal protective equipment, I still never look away from the box while I’m at it. Because her strikes are so fast, It would take less than a split second for her to put a serious cut on any bare skin, so I don’t put anything in harm’s way and I am as efficient as possible when I am exposed.

Some of you may ask, “Why do you put yourself in such a situation?” With all we know about this incredible species, there’s still much we don’t know. Placing bands on the chicks helps us gather information on each individual and the species in general. The small blood samples we take from the chicks helps us know if there are any toxins that could interfere with their reproductive system, or other systems vital to survival. Yes, my actions put me at risk, but the rewards of knowledge that may one day save the species by far outweigh the risks.

Thank you again for the great questions, and I look forward to writing to you after our banding day on 19 May.

#5 - May 6

HELLO ALL!! I’m writing to you on 6 May, in the afternoon. I just looked at the camera and Mom was slumbering peacefully, with her 3 chicks, 2 of which were hatched 28 April and 1 on 30 April. It’s quite interesting to me that one of the eggs hatched so long after the first 2. Two days doesn’t seem that long. However, a theory on why mom doesn’t start continuously incubating until the second to last or last egg of the clutch is laid is so all the eggs hatch in about a 24-hour period, and thus all chicks are about the same size. Even if not continuously incubated at first, the eggs don’t die, but do develop more slowly. One of you asked if a chick can kick another chick out of the nest. Eggs are laid about 2 days apart, and if a female Peregrine has 5 eggs and started continuously incubating with the first egg laid, the first chick would have an 8-day head start in growth over the last chick. With that much size disparity, the first 1-2 chicks would at least muscle out the younger, smaller ones when mom would feed, and the nest would probably end up with just 2 chicks. With mom not continuously incubating until the clutch is finished is nature’s way of making sure as many chicks as possible have the best chance to survive. The chick that hatched 2 days after the first 2 will probably be fine, but will be 2 days behind in growth.

Several of you asked why the other 2 eggs didn’t hatch. There could be many reasons…maybe those eggs somehow developed cracks in their shells and bacteria got in and killed the chicks, or maybe mom’s or dad’s old age meant some infertility. When I band the chicks (19 May) I’ll collect the eggs, but it will be virtually impossible to tell why they didn’t hatch. Over the last 3 seasons our pair has had only 2 chicks hatch per season, so I’m very happy to have a third this year.

Another question is what would happen if one of the chicks died. With all birds in the world, chicks dying in the nest is quite a common occurrence. With some species, the chick is fed to the surviving chicks. With many others including most peregrines, through movement of the other chicks and adults, the dead chick(s) gets moved off to the side. Sometimes parents from other species will remove the chick from the nest.

Another asked if mom and dad are ever in the box together. It’s quite rare to see both birds in the box at the same time. When mom needs a break from incubating eggs or brooding young chicks, dad will come in, mom and dad are vocal for a few seconds, mom leaves and dad takes over duties. He may be with the eggs/chicks for an hour or so, mom comes back, they are again vocal for a few seconds, then dad leaves and mom resumes duties. Dad never roosts in the box, especially during the nesting season. Dad will roost close by in case a predator approaches. Even during the middle of the night both adults will defend the nest. From all my observations of birds I’ve noticed that even day active birds can see much better than humans can at night. I’ll talk to you all next week, and keep those questions coming!

#4 - April 28th

We are in the final countdown. As I write this ASK JEFF installment on 28 April, it should be any day we see little white heads bobbing in the nest, when of course mom gives us a peak as she keeps them warm under her feathers. Young birds can’t regulate their own body heat until they are few days old, so mom must keep them warm. Our female has been doing it for about 13 years now. We can definitely call her a seasoned mom.

I mentioned the following early in the falcon watching season, but want to reiterate the potential of none of the eggs hatching. The female was hatched in 2006 and the male was hatched in 2004. Fifteen and 17 years old are quite old in the Peregrine Falcon world. The reproductive system starts to falter as any bird moves into its later years of life. If we don’t see chicks about 2 weeks from now, it will be safe to say the eggs won’t hatch. I know we are all hoping we see chicks very soon!

The first of your questions I want to answer is actually about the eggs. “Does the mother falcon know if there’s life inside the egg?” The bottom-line answer is no because the female will incubate many days past when chicks should be hatching. However, when a chick is close to hatching, it will start to make noise that the mom can hear. In some species the mom will make noise when she hears a chick in an egg, which is thought to be encouragement to the chick to pip, or break out of the egg.

Another question is what nesting material does the mom use if there’s no gravel to make her scrape, or depression in the gravel so the eggs don’t roll around. None of the world’s falcons bring any nesting material to the nest spot. They only use what’s at the cliff crevasse, the nest cavity (kestrels nest in tree cavities that were made by woodpeckers) or the top of a building. If there’s no gravel, sometimes the eggs roll and the female usually ends up incubating one at a time, which usually means none of the eggs are incubated enough to hatch. However, I’ve seen 2 instances where the female had no gravel on a flat piece of windowsill wood, yet each female hatched and raised 4 chicks. There wasn’t a camera at either nest, so no one knows how each female did it, but obviously some females can adapt to no gravel and get the job done.

“At what age can one tell the difference between the males and females?” This is a good question that I must take into consideration at every Peregrine nest I visit. The males are smaller than the females, and get a smaller size leg band. I must make sure I am placing the right size band on especially the female, for if I were to put a male band on a female leg, that small band would cause problems for the female when she grows to full size. I always make sure the chicks are at least 18 days old before I put the bands on, and I like to band at 20 days old to be fully sure. If when banding I see a falcon chick that is in between band sizes, I always place the larger size band on the leg. To me birds of prey are kind of like some dog types, in that both grow their legs and feet to full size well before the rest of their bodies grow to full size. Legs/feet are so important to each animal that it seems natural selection has placed extra emphasis on their growth. Birds of prey are feeding themselves well before they leave the nest, so they need strong feet to hold prey down and in place as they tear pieces with their beaks.

“Where does the male stay when the female is on the nest?” He usually perches within a few hundred yards of the nest and in full view of it. He would be the first to sound the alarm (get very vocal) and attack if a predator was approaching the nest. The female would hear him and leave the nest to help the male defend.

“Are there falcons that will take over the territory when our pair is gone?” Peregrines were taken off the federal endangered species list in 1998. They were taken off because research proved their population was large and self-sustaining enough that they would thrive and not become extinct. The bottom line is there are lots of Peregrines now. The Portage de Sioux Energy Center nest box and area are great for Peregrines in many ways. For example, there’s a great, safe place to nest (thank you Ameren Missouri staff), their territory encompasses a large body of water that gives them an advantage at catching prey and there’s lots of prey species. I am very confident another pair will quickly take over when our pair is gone. I am also confident each of our parents have had to fight off, or defend this territory from many other Peregrines that challenged for supremacy. Our female has successfully defended for 7 nesting seasons and the male for 6.

For the last question, someone asked if Peregrines migrate in large groups because they saw a group of 50 or so birds that looked like Peregrines. Peregrines are solitary migrators. It is rare to see even 2 together during fall or spring migration. If I had to guess what type of bird this person was seeing, I would guess they saw a flock of gulls, which have a similar silhouette and do migrate in large flocks. There are several gull species that can be seen in/near St. Louis. As a side note, the Peregrine pairs in the great St. Louis area don’t migrate, staying on or near their territories year round. If any of the Peregrine team sees a chick in the nest, I’ll be quick with the next ASK JEFF. Take care everyone!

#3 "Old Man" Incubating the Eggs - April 13

Hi Everyone!

As I write this (13 April about 1:30), I’m watching the male incubate the eggs. As a refresher, the male is at least a third smaller than the female Peregrine, and with 5 eggs to incubate, you can probably guess the male struggles to get his whole body over the eggs to keep them warm. He also uses both his wings to help keep the eggs under him.

As much as I have to snicker at his incubation antics, I am in complete admiration of this “old man.” Last week it was confirmed he’s the same male since the 2016 season. He has a black over green colored band. Within the black field there’s a D, and within the green field there’s a 53. This band allows me to trace his origin. Way back in 2004 this bird was hacked from the New Madrid power plant, in New Madrid, Missouri. Hacking is releasing a bird to the wild that was hatched and raised in captivity. Hacking helped remove the Peregrine from the federal endangered species list. World Bird Sanctuary hacked over 80 Peregrines. The reason we stopped hacking is because we began to find many wild Peregrine pairs raising their own young in the greater St. Louis area; the ultimate goal of hacking. If my math’s correct, our “old man” is almost 17 years old. He’s still physically fit enough to defend his territory and hopefully father this year’s chicks. Yes, I admire this seasoned veteran.

Since ASK JEFF NUMBER 2, I’ve had only one question to answer. When will the eggs hatch? Based on my observations, the eggs should hatch sometime between April 25th and 30th. Incubation time is not an exact science, but for Peregrines it’s roughly 30 days from the time the last egg of the clutch, or group, is laid. The last egg was laid about 26 March. I’ll write again next week!

#2 Four More Eggs - March 30

Hello Everyone!

Since I wrote to you last, there have been 4 more eggs laid. The 5th one was laid sometime yesterday evening. As a refresher, our female, which is now confirmed the same female from the last 6 seasons, usually lays 5 eggs. The last couple of years only 2 of the 5 eggs have hatched, but less fertile eggs in a clutch is one of the expectations from a male and female as old as our pair. While not yet confirmed it’s him, the male from the last 5 seasons is a 2004 hatch and the female is a 2006 hatch. Seventeen and 15 years old, respectively, is quite old in the Peregrine Falcon world. Because of age, one of the first systems to start to not work as efficiently is the reproductive system. As much as I could say none of the eggs may hatch, I’ll say all 5 could hatch. We shall see what’s under mom in about 30 days from today.

I just spied on mom. She was incubating the eggs, dozing off, gazing out the front “window,” dozing more, gazing, dozing…this pattern will go on for most of every 24 hour period until late April, when the eggs are due to hatch. The male will fly in to incubate the eggs 2-3 times a day, but usually for an hour or less per break. When the female leaves she’ll go to a spot to collect the prey the male has provided, eat it, preen (care for her feathers) after her meal, then fly back to switch with the male. While it’s hard to tell which bird is on the eggs, try to do some rough measuring each time you look. The female is much larger than the male, so of course takes up more nest box floor space. Pick known spots on the front rail of the box near where mom’s head and end of tail are, and then reference those spots every time you look. When you see the bird that easily fits within those reference points, you will know you are looking at the male.

Now to last week’s questions. Several asked about the lab results from last year’s chicks. As a stark reminder, a few hours before I was going to band the chicks last early May, both died. I was able to quickly retrieve both chicks and get them to our vet for necropsy (an animal autopsy) and tissue samples. Unfortunately, there was nothing conclusive on why the chicks perished.

Someone asked about sleep patterns with our Peregrines, since this person sees the same thing I mentioned above. While I don’t know of their sleep patterns except to say they get a little more sleep during dark hours, I can tell you birds are light sleepers. There are few birds in the world that don’t have to worry about the animals that can prey on them. Birds have the ability to wake up from the slightest, out of the ordinary sound. For example, a song sparrow roosting on a low branch of a young red cedar probably has the ability to phase out the sounds of wind blowing through the bows near its roost. However, it will quickly wake up when a raccoon steps on and crunches a dried leaf as it approaches the cedar. Our female may fall asleep as we watch her incubate during the day, but would probably quickly wake up if she were to hear the male get vocal if, say, a bald eagle approaches the nest.

Another asked about the egg laying behaviors of the female. The female looks terrible just before she’s going to lay an egg. She will fluff up her feathers, breath quickly and sometimes heavily, and sometimes half stand up just before the egg drops. I’ll bet all the human moms out there can feel for our female during egg laying.

I saved for last this question; were the Peregrines brought here to do “crowd control” on pigeons? I hope many of you chuckled at the wording of this question as I did, but it’s a great question! It’s a safe assumption that any tall structures, whether they be human made or natural (eg. cliffs), will have a lot of pigeons living on them if those structures are on rivers/lakes with barge traffic. I don’t know all the stats, but would guess a large portion of the grain grown on U.S. soil is moved to/from granaries by barge. I believe that’s accurate because I know millions of tons of grain is moved by St. Louis by barge. For those that traverse the vehicle bridges over the Mississippi River near St. Louis, take a close look at the light posts and high electric wires on/near these bridges and you’ll probably see hundreds of pigeons there. They are waiting to feed or have just finished feeding on the grain that’s spilled atop the barges as they were being loaded. Peregrines feed almost strictly on other birds, and pigeons are definitely on the menu. Peregrines, like most other birds, will find territories that among other thinsg, will provide them with the best opportunities to catch food, and Peregrines will nest on the same tall structures the pigeons like to live on. Power plants on large rivers/lakes, with their tall stacks and other structures, produce living opportunities for both pigeons and Peregrines. Those that manage power plants, and any other tall buildings close to rivers/lakes in the situations mentioned, would much rather deal with a pair of Peregrines than hundreds of pigeons. To finally answer the question, Peregrine nest boxes are placed on these human made structures to lure Peregrines in so they can provide “crowd control” on pigeons.

Thanks for all the great questions! Can’t wait to write to you next week.

#1 Nesting Season - March 23


I’m so excited for the 2021 nesting season to get started, and to let you in on a little secret, the season started Sunday, 14 March, with the first egg laid. With the cool, wet weather we’ve had since Monday, the female is incubating more than she normally would, but she must so the eggs don’t get too cold and perish. As a refresher, many raptors around world don’t start faithfully incubating until the clutch, or season’s group of eggs, is fully laid. With the eggs being laid about 2 days apart, if the female faithfully incubated starting with the first egg, the first 2 chicks hatched would have such a head start in growth, they would probably outcompete the other chicks, and the pair would end up fledging less chicks (fledging is when a chick leaves the nest for good). Faithfully incubating just after the full clutch is laid allows for the eggs to hatch close to the same time, so the chicks are roughly the same size.

We don’t know if this year’s female is the same we’ve had since 2015 (or male since 2016), but signs are point toward “same female;” the biggest sign being she’s an incredible nest protector. She so protective, even during the non-breeding season she will attack anyone that tries to get too close to the nest. She doesn’t just fly by and yell at you, like Sioux-Zee did. Sioux-Zee’s the female from the first 3 years of our nest cam. Our current female will hit you with her very strong feet and pointy sharp talons, as she flies by at around 100 mph. My yellow hardhat has the scars to prove it! Our current female is the reason our camera quality is poor, and unfortunately will be for the season. We have this beautiful, brand new, high picture quality camera, all wired up and ready to go…that’s sitting on a team member’s desk. Might as well be a paper weight. Yes, she may be hard for us to handle, but beware any aerial predator that tries to eat her chicks. That predator could literally lose its life trying to secure an easy meal. In my experience our female is unmatched in Peregrine Falcon nest defense.

Remember to submit your questions to the Peregrine Cam website, and I’ll answer as many as I can for my weekly ASK JEFF segment. I’m already looking forward to writing to you next week!

#1 Nesting Season

HELLO EVERYONE! I am so glad to be able to be writing about our Ameren Missouri’s Sioux Energy Center Peregrine Falcon pair, for the 9th year in a row. As you may have been able to see, the female is on 3 eggs now. I’ve some very exciting news to get to, but first I must refresh everyone’s memory on what happened last year.

It’s never a great thing to have to bring up such a negative circumstance, but in the world of wild Peregrine Falcons, it’s something that happens a lot more than most would imagine. The 2 chicks that were growing just fine, and only 3 days from being banded, suddenly died. When chicks are first hatched, they cannot regulate their own body heat, and therefore must be brooded, or kept warm by mom. Once they reach a certain size, mom stops brooding them because they can regulate their own body heat. Last year’s chicks had already reached the age where the female was coming to the box mostly to feed them, but not lingering long. No one realized the female had abandoned the chicks until it was too late.

When we get as far into the nesting season as we did last year, and the female is suddenly gone, one of two things can be assumed. First assumption; the female somehow died while away from the nest.  Second assumption; the chicks died and when the female came to the nest and realized they had, she abandoned the nest. With the chicks seemingly healthy, my first assumption was the female died. That assumption has been proven wrong. She’s back!

We know it’s our female because of the bands she has on her legs. On her left leg she has a black over green band.  In the black colored field there’s a sideways D. In the green field there’s a sideways V. The green field has faded considerably, so the band had to be in just the right light to see it. Our great and diligent cameraman not only focused in to get the sideways V, but was also able to get a good look at the band on her right leg. That band is a United States Fish and Wildlife Service band, and we were able to see enough of the numbered sequence to get the positive ID on her.  To refresh, our female was named Lizard by the person that banded her on a cliff nest within a Minnesota state park.  Lizard was banded as a chick in 2006. The male of this year’s pair, the same male as the last 4 years, was banded and released through the process of hacking, in 2004, at a power plant in southeastern Missouri.

The second assumption about the 2019 chick deaths is probably what occurred. The chicks died at about 17 days old. There are many diseases birds die from, and without being able to collect the bodies quickly, we weren’t able to find a reason. Our team deeply cares for the well being of our Peregrines, but a higher priority is our safety.  It’s no easy feat getting to the nest box, and by the time we would have been safely able to get there, the bodies would have decayed enough where it would have been very hard to find cause of death. We shall all look at 2019 as a tragedy, but our female produced and raised to fledging 12 chicks the 4 years before that. In Peregrine Falcon nesting terms, that great success. We shall all hope she continues her success in 2020.

Please remember to send us your questions. I’ll be answering them weekly, along with updates on our pair, and hopefully in mid April, all their chicks.Talk to you soon!

#2 Sitting Tight

Hello everyone! As of today, 27 March, our female is on 4 eggs. She’s what I call “sitting tight,” which means only moving off the nest when the male brings her food and she takes a break from incubating. For these short breaks (rarely more than an hour), the male does his best to fit his significantly smaller body over the eggs to keep them warm. Sitting tight also signifies she has her full clutch. A clutch is the number of eggs a female bird will lay for a particular incubation period. With Peregrine Falcons, they spend so much time courting, selecting a nest site, incubating, then raising their chicks that they can afford only one clutch per year. Birds like the Eastern Bluebird (Sialia sialis) may have 3 clutches of eggs in a year, with the time for their courting, selecting a nest cavity, nest building, incubating, and chick raising significantly shorter than Peregrines.

You may notice in the above list of activities for each species that I didn’t mention nest building for the Peregrine. Bluebirds nest within cavities of trees or of course in a bluebird box one may affix to a tree, pole or fencepost in their yard. Within the cavity they will build quite the elaborate nest, consisting of different grasses found within their territory. The grasses are fashioned into a circle a few inches deep, with a bowl at the top so the eggs stay put. Peregrines, and falcons in general, don’t use any materials for their nests. Peregrines will usually find a crevasse in a cliff that has gravel or dirt on the floor, and make a depression, or “scrape,” to lay eggs in. The scrape keeps the eggs in one spot. Other falcons of the world, for example the Merlin (Falco columbarius) may nest in a stick nest that was previously made by another raptor. Merlins migrate through Missouri and Illinois, but usually nest further north in our country and into Canada.

No one asked questions during the previous week, but I understand we are just getting started. Remember, folks, any questions you have about our Peregrine pair you can ask through the websites of Ameren Missouri, Missouri Department of Conservation and World Bird Sanctuary. Talk you next week.

#3 Incubating, Hacking, and Longevity

Hello All! Here we are, smack-dab in the middle of the incubation cycle. If you like to watch mom doze during the long hours, then there’s plenty of entertainment. If you’ve been or will be lucky enough to see the male come in and switch the incubation roll with the female, that would certainly be more exciting. The switch can happen any time of day, so hard to set your clock by it. Last year there were 5 eggs for him to try to spread his much smaller than the female’s body over. Our cameraman got comical footage of the male trying his best to fit over the eggs. He’s got it a little easier this season with 4 eggs in the clutch. Lucky for the eggs mom’s incubation breaks rarely last more than an hour, but as you know, we’ve had a lot of success over the 9 seasons we’ve been watching these incredible birds. They are definitely doing most everything right during incubation.

Let’s get right to your questions. In this season’s first ASK JEFF I used a word to describe how the male of our pair got into the wild. The word is HACKING, and someone asked what that is. Especially before the Peregrine came off the endangered species list (1998), humans made a concerted effort to help the species’ wild population increase. We took chicks hatched in captivity and “hacked” them to the wild. WBS hacked captive-raised chicks from 1985 until about 1995. By 1995 we had several Peregrine breeding pairs in the area, which is the ultimate goal of hacking; the birds released start to produce chicks. Several St. Louis organizations built hack boxes on their roofs, then WBS placed the 35-day old chicks in the boxes. The chicks were locked into the boxes, but the boxes had a big, barred window so the chicks could look out into the spaces they would eventually fly in. At about 45 days old, the chicks were removed from the box, transmitters and bands were placed on their legs, the barred window was removed and the chicks were placed back into the box. At that point they could fly, so they came and went as they pleased. Since the chicks had been fed in the box for about 10 days before their release, they would continue to come back to the box because they knew it provided food (provided by hack site attendants). This is important in hacking process, since a just fledged chick doesn’t have the flight skills to catch other birds in the air. Over 4-6 weeks after release the chicks learn how to catch food, and they eventually wean themselves from the hack box. Back in 2004 our male was hacked from a power plant in SE Missouri.

Another question was longevity of wild Peregrines. With our female being 14 years old now and the male 16, they are near the end of their lives. I would be surprised if one or both were back for the 2021 nesting season, but no need to fret if they don’t return. Because of our pair and many thousands of others in the nation, there are many Peregrines in the wild now. Ameren’s Sioux Energy Center is a prime place for Peregrines to nest, so I’m confident we will have a breeding pair there far into the future.

Last question for the week was when our eggs are expected to hatch. Our first egg was laid on about 11 March, and last laid on 20 March. The female won’t start consistently sitting on the clutch until it’s finished, with the theory on this being all the chicks in a clutch will have a better chance of surviving if they all hatch on the same day. If she started incubating the eggs as they are laid, the chick from the first egg laid would have a 6-9 day age (and therefore size) advantage on the last chick hatched. The last and probably second to last chick hatched would probably be outcompeted for food. The eggs should hatch on about 20 April, give or take a couple days. With all we know about the world’s birds, it’s still hard to predict the exact day eggs will hatch. We on the Sioux falcon team do not count our Peregrines before they hatch!

I’m already looking forward to talking to you next week.

#4 Design of a Nest

Hello all! On Thursday morning, 9 April I watched the camera for about a half an hour before I started writing this week’s Ask Jeff. Our female slumbered for most of the timespan, yet at the end she busied herself moving the pea gravel with her beak, at least the pea gravel she could reach without getting off her eggs.  She pulled some up close to her, and other times she moved pebbles away.  When there’s seemingly nothing better to do, I guess priorities shift to make sure the pebbles within her reach are placed exactly how she wants. Around 20 April we should see the fruits of her seemingly boring labor.

Nest building is not a priority with any of the world’s falcons. They only fashion a depression within whatever substrate is at the location, lay their eggs in the depression and then incubate. Many of the world’s birds construct elaborate nests, using sticks, greases, mud, sand mixed with rotting vegetation and sometimes even human made objects.

Bald Eagles (Haliaeetus leucocephalus) build the largest nest of any of the world’s birds of prey. They start the base of their nest (usually built in a very tall tree) with quite large sticks, sometimes as long as 8 feet.  From the base to the top can be many feet thick, and across the nest top can be 10 feet wide. The bowl of the nest, where the eggs will be laid, consists of grasses or dry aquatic weeds.  These softer items help cushion eggs and aid in keeping the warm temperature needed for incubation. The record Bald Eagle nest was built in Florida late last century, and it measured 9.5 feet across the top, and was 20 feet tall.  Someone actually weighed all the sticks after the tree it was built in broke, and the nest weighed 2.9 tons!

Barn Swallows (Hirundo rustica) and Cliff Swallows (Petrochelidon pyrrhonota) build a nest with mud and grass. These swallows must find mud of just the right consistency, mix the mud with the dried grasses at just the right time so the mud/grass mixture sticks to the rock, barn or steel wall they build the nest on. Especially with Cliff Swallows, their nests hang precariously over water bodies, almost always with an overhang, so the nests can’t get wet from rain. Most of the large river bridges in our area are colonized by Cliff Swallows.

The Malleefowl (Leipoa ocellata) from Australia is a bird about half the size of a wild turkey and is related (quail, chickens, pheasants, turkeys are all in the Galliformes order of birds).  With his feet the male Malleefowl scrapes a 1-3 foot deep and 6-8 feet wide depression into the sandy ground of its habitat, fills the depression with a mixture of dried and leafy vegetation, then kicks sand over the vegetation to make a pile about 2 feet tall.  Again, with his feet he excavates a nest hole between sand and vegetation, the female lays as many as 30 eggs in the hole and the hole is covered with sand.  The rotting vegetation under all the sand provides the warmth the eggs need for incubation. The male will kick sand from or kick sand back on the top of the mound to keep the mound at a consistent temperature.  This pile, depending on the warmth of the day, can consist of 5-8 tons of sand/vegetation. Upon hatching the chicks dig their way to the surface of the mound, move into the brush and can run fast and fly well within a day of emerging.  Neither the male or female provide any protection for the chicks. Chicks of all Galliformes birds are called precocial, meaning they can move well and feed themselves at very young ages.  Bird of prey have altricial chicks, meaning the chicks must have lots of parental care from hatching to even well after leaving the nest.

Keep those questions coming, folks. I’m already looking forward to writing to you next week.

#5 Inspirational Wings

Hello all!  Here we are, just 5 or so days from our chicks hopefully emerging from their eggs. Yes, not the most exciting of times, as evidenced by our female doing a lot of slumbering as she adheres to her very important job. This morning, Wednesday, 15 April, I did about 20 minutes of watching. In the AM the sun sheds perfect light on our female, and I’d guess she enjoys the warmth on these recent, chilly mornings. When one knows how fast a Peregrine can travel as it pursues its prey and how far one can travel during migration, seeing one sit in the same spot for such long stretches of time brings some irony to its otherwise rapid lifestyle.

I have a cousin I grew up with in NJ, and as we went through high school and then college, we became close friends.  He now lives in AZ, but we keep in regular touch with each other. My cousin is a huge fan of human flying machines, and regularly watches fighter jet airshows or parks near a military airport close to his home, just to watch the jets come in and leave. I, too, get a huge kick out of fighter jets passing by, and over those later years in NJ my cousin taught me how to identify the fighters, and I taught him how to ID birds.

I will always wonder if our world didn’t have birds in it, would we have ever developed the airplanes that take us around the world, and probably someday, to outer space. There’s so much technology that goes into, say, a passenger airliner; its radar, communication and pressurization capabilities, and of course the huge engines that thrust its hundred or more tons into the air. If its wings weren’t fashioned like those of a bird, all the technology would be worth nothing.

Around 400 BC the Chinese developed kites. Because a kite is fashioned like a bird’s wing, the kite continually lifts into the air, but needs force pulling it down to do so. Those that have held the string that’s connected to a kite know the upward force the kite exerts.

Around 1485 Leonardo da Vinci studied and wrote about bird wings. He made drawings of flying machines that he thought could carry humans, but da Vinci lacked the technology to develop his machines.

In the early 1800’s George Cayley, and English Baron, experimented with wing design and developed the first glider that carried a human. The human was a child.  I wonder how George ever convinced the child’s mother that all would be fine! George is considered the first true scientific investigator of flight and the first person to understand the principals and forces behind it.

On 12 December 1903 Orville Wright became the first human to fly on a motorized airplane. Before he and his brother Wilber ever accomplished this, they put plenty of study into a bird’s wing.

On studying how a wing works, one must look at its lengthwise cross section. Imagine your eye at the tip of the wing and you’re looking toward the bird’s body.  Cut the wing between your eye and the bird’s body and you will see a cross section with a lower edge that’s concave and an upper edge that convex. Because the upper edge is convex the air moves faster over it than the concave, lower edge. There are You-Tube videos showing this (just write into your internet search bar “how a wing works”). The faster the air moves over the upper wing, the lower the air’s pressure becomes. The pressure of the air moving under the wing is higher because of the lower edge’s concave shape.  High pressure under the wing and low pressure above causes the wing to lift.

Of course a bird, insect, bat or airplane needs a force to push it through the air. Maybe next week we can talk about how a bird’s wings create that force.

Nature has provided humans with so many things essential to our lives.  Let’s all continue to keep her “flying” at top speed. Reduce. Reuse. Recycle. Conserve. With the current times I will definitely add, “STAY HEALTHY!” Keep those questions coming, and I’m already looking forward to ASK JEFF #6.

#6 Waiting for the Hatch

Greetings everyone! As I write this on Thursday, 23 April, we are into the third day since the eggs were due to hatch. I’ll throw out the reminder that predicting when a wild egg will hatch is like predicting the weather; it’s not an exact science. There are many variables that affect egg development, with temperature consistency being a big one.  For example, if the mother has to leave the nest to help the male defend their territory, the eggs could become chilled enough to lengthen development time. The humidity of the environment under the mother as she incubates can also affect egg development. This morning at about 11:40 the male flew into the box to give mom a break. From the time she hopped off the eggs to the time the male was settled on them took about 15 seconds. These quick incubator changes help us understand how important consistent temperature and humidity are.

One of the questions over the week asked what happens to the unhatched eggs after the fertile eggs hatch. When the chicks first hatch, they must be kept just as warm as the eggs, since birds can’t regulate their own body heat until they reach a certain size and grow the downy feathers needed for insulation. Peregrine Falcon eggs in a nest usually hatch within a 24-hour time period, so it becomes evident fairly quickly what eggs won’t hatch. Yet both parents seemingly continue to incubate the unhatched eggs. Especially once the chicks become more mobile, the unhatched eggs naturally get pushed aside. Those eggs eventually break and the shell pieces become part of the nest substrate.

Another question was asked about a clutch of Peregrine eggs in a nest near San Francisco. The parents abandoned the eggs. Just like the actual number of days it takes a wild egg to hatch, there are many variables that could explain why eggs would be abandoned. One example is one or both parents were somehow killed. Peregrines, as well as all wild animals, lead a hard life. Maybe the eggs got chilled for too long and died. Sometimes an egg gets a minute crack that allows bacteria to enter the egg. The infection could kill the egg. Even if eggs are quickly collected and analyzed, it still may not be determined how the egg died.

Hopefully when I’m writing ASK JEFF #7 I’ll be talking about the new chicks and answering all your questions. Have a great week and stay healthy!  

#7 And Then There Were Three

Hello Everyone!

The blessed hatching occurred either late Friday night, 24 April, or early Saturday morning, 25 April. Three of the 4 eggs hatched and mother falcon now is caring for her hatchlings. Today, Wednesday, 29 April, is quite chilly, rainy and windy, with only a high of 50 degrees. Because the chicks, at only 4 days old and cannot regulate their own body temperatures, mom is busy brooding, or keeping the sometimes squirming lumps warm. I’ve looked in 3 times today, and she seems uncomfortable. Because of their size she can’t put all her weight on them, so has to half stand and use her wings to keep the chicks under her.  She’s diligent, though, and with all her successes in the past, we know she will perform her work well.

Banding day will be 15 May. I personally like to band the chicks when they are around 20 days old. By that time they are already showing the male/female size difference. With most birds of prey, females are larger than males. Also, at 20 days their feet are about as large as they are going to be for life. I liken raptor chicks to puppies, which have full grown feet well before their bodies are full grown.  Because of the size difference in the sexes, females get a size 7A band and males get a size 6 band. At 20 days I know what size band each bird gets.

The one question I got over the week was when the parents will not have to brood the chicks anymore. When the chicks are 9 or 10 days old they have big enough bodies and enough insulative down that the parents should stop the brooding. This timing is also dependent on the outside temperature. By Saturday the temperature is supposed to be back in the low 80’s.  You’ll not see mom or dad brooding them that afternoon, but then probably will resume as the sun sinks below the horizon.

There will certainly be more to come as our chicks grow. Keep those questions coming. Talk to you next week.


#8 Protective Parents

Hello All!

Today, Friday, 8 May, the chicks are 13 days old, looking healthy and growing like weeds.Today is chilly; only highs in the 50’s with a stiff wind blowing. Every time I looked at the nest cam today mom had the chicks against or very close to her body. The chicks are too big for mom to get them all under her body, but she still is sheltering them with some warmth and wind blockage. On days with 60-degree temps or more mom doesn’t have to stay so near them because the chicks can mostly regulate their own body temperatures now. I say “mostly” because on cold days/nights mom still must be very near them.

We had some good questions over the week, so let’s get right to them. The first fits in well with my above paragraph. “How long does mom leave the babies alone when they are this young?” There are plenty of perches within 20 feet of the box where if mom was on one of them, you couldn’t see her on camera.  The chicks will fledge, or fly from the nest, when they are 45-55 days old. They have to be much closer to that age frame before mom will venture further from the nest.  She not only broods and feeds the chicks, but she’s the number one nest protector.  If any other bird or mammal (including humans) come close enough to the nest, she will attack, flying close enough to the threat to rake it with her strong feet and sharp talons.  She also has a very loud voice, and usually flying close to the threat without touching it, yet yelling so loud, the threat gets the picture “loud” and clear and retreats.

Someone observed the mother falcon standing over the chicks with her mouth agape. That person asked if mom was communicating with them.  Falcons and other birds of prey have been observed making noises just before egg hatching, with the theory on this being mom encouraging the chicks to break through, or pip the egg.  Mom and dad falcons seem to “talk” to each other, especially during courtship. They also become vocal during exchange of incubating duties.  I believe the person making the observation with our falcon was seeing mom panting. Birds don’t sweat like most mammals. They cool themselves by rushing air across their moist mouth and throat parts. The evaporation of liquid within the mouth helps cool the bird.

Another question was what does the male do all day long when he’s not incubating the eggs or brooding the chicks. I mentioned mom is the number one nest protector. Dad is a close 2. If, say, and eagle ventures too close to the nest, dad is the first responder. He will fly above the eagle and attack from above. If he thinks he can get away with it, he’ll rake his feet and talons across the eagle’s back. He’s also very loud.  Whether male or female attacking another bird of prey, the falcons know to be cautious. Again, I’ll use an eagle as an example. If the eagle sees what’s coming, in a split second it can roll over, feet flashing up and grab a falcon that gets too close.  The eagle would make short work of the smaller bird of prey, killing and then eating it. Yes, even the fastest of all the world’s animals can become a meal for another animal.  Dad also defends the territory from other Peregrine Falcons and is always on the look-out for the chick’s next meal; his and mom’s, too.

Last question was, “Do male and female ever spend time together in the nest box?”  They spend very little time in the box together, and for that matter, very little time perched close together.  Affection is not on a bird of prey’s list of behaviors. They may mate in the box, but that process is very quick; literally a few seconds.  When dad comes into relieve mom of incubating duties for a few minutes, he lands and jumps in the box as the female jumps out. When dad brings food, mom flies out, meets him in midair and they do the exchange, usually quite spectacularly from a human’s point of view.

The chicks will be banded next Friday, 15 May, around 9 in the morning. The camera is turned off for the hour or so it takes to extract, band and put back the chicks. Late Friday morning you will see the chicks’ new jewelry, which helps us biologists gain knowledge on their movements around the continent, nesting behaviors, etc. I’ll report on their health and the experience next Friday afternoon. Until then, keep those questions coming!  Have a great week.

#9 A Sad Day

Hello all. We’ve had tragedy at the nest box. This morning as I was getting out of my vehicle at Ameren’s Sioux Energy Center to get ready for banding our 20-day old chicks, I was informed that 2 had jumped from the box and one had passed away in the box. The chick that passed away in the box died sometime overnight. Around 6 this morning the other 2 jumped from the box. With the chicks not even walking on their feet yet, them jumping from the box was very surprising.

I still climbed to the box to retrieve the passed chick that was still in the box. I found another just under the box, where 2 I-beams come together. That chick was also dead. The third chick fell to the ground. All 3 bodies will be necropsied (that’s an animal autopsy) and we will try to find out why the chicks so suddenly died.

The person that pans the camera looked at recorded footage from last night. He watched until he could not see into the box because of darkness. Nothing about the chicks’ behavior gave him any hint there was trouble.

When I climbed onto the beams near the box to retrieve the chicks, mom falcon acted as normal, pummeling my yellow helmet with her feet as she rapidly flew by. Dad falcon was also flying very close, yelling at me. The box had feathers from prey items, just as normal.

This tragedy was the last thing I expected, as WBS staff person Darcy Evelhoch and I made our way to the Sioux Energy Center early this morning. In previous ASK JEFF’s I’ve spoken of how nature can seemingly be cruel, not only in our situation, but with all other living things on the planet. Still, when you get to see so much of our Peregrine Falcon pair and the chicks they produce and raise, one cannot help but become attached. My attachment comes through in the respect I have for the species, our 14 year old female and her 16 year old mate. They have been together for 5 seasons now and have contributed 8 fledglings to the North American Peregrine population. I really didn’t think the last ASK JEFF would come so quickly in the nesting season, but again, nature has her own agenda, and it sometimes doesn’t work out for the human onlookers. If we get definitive answers from testing the chicks’ bodies, I will write another ASK JEFF. I hope everyone has a great summer, and I look forward to writing to you in 2021.

4.7 - 2019 Nesting Season

Hello everyone! Yesterday morning (18 March) we found the first egg in the nest. This signifies the start of the 8th year we will show you the nesting lives of Ameren Missouri’s Portage de Sioux Energy Center Peregrine Falcon pair. For those of you that have watched over the years, you will probably notice the box is in the same location as all years past. Back in early January I replaced the gravel in the box and gave the box a good inspection. It’s more than sound enough to house our Peregrine pair and their chicks for another year.

The gentleman that runs the camera has been keeping a close eye on the box, and he and I have already determined we have the same male and female as last year. As a refresher, the female is a 2006 hatch and was banded as a chick in a cliff nest at a state park in Minnesota. This is her 5th year as Portage de Sioux’s breeding female. The male is a 2004 hatch, and this is his 3rd year as the breeding male. He was raised in captivity and released to the wild (the process known as hacking) at a power plant in New Madrid, Missouri. Of course, we know the histories of each bird because of the bands they have on their legs. If you get a chance to see the legs as you watch, the female has a 2-colored band, black over green, with a sideways D in the black field and a sideways V in the green field. The male also has a black over green band, with a normal D in the black and a 53 in the green. If you have the privilege to see both birds at the nest box, the female is considerably larger than the male, which is typical with birds of prey.

I’m looking forward to again fielding your questions as the nesting season unfolds. I’m very excited that we are able to watch again, and I wish our nesting pair the best of luck for the 2019 season.

4.7 - Mom Lays Five Eggs

Hello all! Our female, being 13 years old this year, has done it again. She’s managed to lay five eggs, just like last year. Thirteen years old is quite old for a Peregrine, and the male is 15 this year. Just like humans in their later years, bodily systems don’t work as efficiently as when we were younger. There’s more of a chance some of the eggs won’t hatch, but of course we will hope for the best.

If my calculations are correct, our female laid her last egg on March 26. She laid her first egg on March 18. Peregrines usually lay an egg every two days until the clutch, or full number of eggs laid, is finished. The incubation period for a Peregrine egg is about 30 days, so the chicks should start hatching around April 26.

You may notice I used words like “usually” and “about” to describe egg laying and incubation period. As much as we know about birds, there are still variables that could make small changes in the number of days between eggs laid and egg development during incubation. If our female had three days between, say, egg three and four, then the hatching date could be off by a day or two. If mom had to leave the eggs to, say, defend the nest from another bird of prey, egg development could have slowed, which may change the hatch date. Most birds usually (there, I used it again) won’t start constant incubation until the full clutch is laid. This delay in incubation makes it so all the eggs hatch in about 24 hours. In the Peregrine world, mom and dad will feed those chicks that push, squabble and get closest to mom/dad as they present the food. Birds grow so quickly that if there were two days between the ages of each chick, the first two or three hatched would be bigger, stronger and would probably get most of the food, and the two smallest would more likely perish. Having all the chicks hatch within 24 hours makes it so they are roughly the same size, and each will have a great shot at getting their fair share of the food and surviving to fledging (flying from the nest).

I look forward to any and all questions you may have.

4.12 - Mom Gets a Break

We’ve had the privilege of watching the Ameren Missouri’s Sioux Energy Center Peregrine falcons for 8 years in a row. This pair is now into the incubation period by about 14 days. I’ll admit there’s not too much to see as the female provides the warmth that allows the eggs to develop into chicks. I’ll use the example of raking leaves. Yes, not the most stimulating of jobs, but when you are done, take a step back and look at your yard, you almost always say, “Wow, that looks nice!” I know we will all be elated when in two and a half weeks or so our female gets up from her scrape and shows us her beautiful chicks.

Earlier this week I was watching and got to see some entertaining footage of the dad keeping house. When I turned on the feed, I could tell the male was on the nest. A couple of times a day the female takes a break, and the male flies in and assumes incubation duties for sometimes as long as an hour. I could tell the bird I was looking at was the male because he’s considerably smaller than the female, and just doesn’t take up that much space in the nest box. Take a look. For those that don’t already know, there are five eggs. When the female incubates, she has no problem covering all five with her bigger body, and seems to be comfortable enough to even doze off as she sits. Not so with the male. With the smaller body, I had to laugh out loud as he got up, changed angle, settled back down, then got up again, changed angle, settled down, then got up…you get the picture. He had to use his wings to help keep the eggs underneath him. Several times he also gently used his beak to push an egg back under his breast. It was so obvious he was not comfortable with all the “lumps.” After 10 minutes of this, I saw that he was looking up at something, and even slowly turned his head to follow the progress of the invisible-to-me entity. Of course it was the female, probably soaring on a thermal, enjoying the last minutes of her break. The male gently got off the eggs, stretched his sleek wings above his body, hopped to the perching in front of the box, then jumped into the blue. About 1 minute later, mom landed on the same perching, stepped into the box, balled up her feet and settled on the eggs. There’s a theory that a female raptor’s body is larger than the males so she can more easily keep the eggs, and then young chicks, warm. From what I observed, I’m in 100% agreement with this theory.

There were a few questions this time! Thanks to those of you who took me up on the challenge from the last ASK JEFF.

First question is how high off the ground is the nest box? It’s 167 feet from the ground. I do not have to climb all that way. Most of that distance is covered by an elevator ride. The last 30 feet are ladders.

Second question is what happens to a chick or chicks that die as youngsters? Are they consumed by the parents or other chicks? With Peregrines it would be quite rare for a dead chick to be eaten by its nest mates or a parent. The parents are great food providers and would have had to fall on hard times for this to happen. One of the theories on why any mated pair of birds settles on a territory is food abundance.

Last question is would I intervene and remove a weak chick to correct the health issue and then get it back to the nest? I would not, with the main reason being the disturbance I would have to create to climb to the nest to remove the chick, then have to climb to it again to put the chick back in. Climbing to the nest creates stress on especially the parents, so I make sure I go to the nest only once to place the bands on the chicks and draw a small sample of blood to make sure there are no human made toxins within. The scientific knowledge we gain from placing bands on the chicks and knowing what is and isn’t in their blood is the only instance worth placing stress on the parents. When I climb I make sure all my actions, and the actions of those around me are efficient, so the chicks are removed from the nest as little time as possible.

Great questions, folks! Keep them coming. Talk to you next week.

4.26 - MODOT Finds a Surprise

Hello Everyone!

I got a call from a photographer in the Hannibal, Missouri area, and he told me he was watching a Peregrine that consistently perched in a group of cottonwood trees just upstream from the bridge that takes interstate 72 and U.S. route 36 across the Mississippi River. He sent me pictures, and sure enough he got some great images of an adult Peregrine. The bird’s consistent position peaked my interest. First, I know Peregrines like to nest on bridges crossing large bodies of water. Bridges provide good hunting perches for this bird-eating predator. As birds try to fly across the Mississippi, Peregrines streak to them to try to catch them before they can get to cover. Second, what caught my interest most is bridges provide safe nesting places for the falcons. I asked the photographer if he ever saw this bird flying up and under the bridge, and he said he’d seen this behavior several times. I speculated the photographer was taking pictures of the male of a pair, and the female had her nest on the underside of the bridge.

My speculation was turned to truth when a Missouri Department of Transportation (MODOT) bridge engineer saw the four eggs on a steel beam when he was performing an inspection of the bridge on the same day the photographer sent me the pictures. MODOT was going to hang a “snooper” scaffold under the bridge over the next two days to continue their inspection, but once they found out the Missouri state endangered Peregrines were nesting there, they postponed their inspection until after August 1. (A special thanks goes out to MODOT for this postponement.) The nesting cycle would be over by that time and they could do their inspection under safer conditions. Yep, the birds would be done with their nesting, and just as importantly, the workers would be safe from attacks by the female as she defends her nest. Once the chicks leave the nest the female mostly loses her need to defend the nest. If there’s anyone that knows how viciously a female Peregrine defends her nest, it’s certainly me! Over the last four years at the Sioux Energy Center the female has struck my helmet with her feet at least 30 times per nest visit, as she tried to push me away from her precious chicks.

So, all parts of the above story are quite fascinating to me, but the one bit of information that spun my mind into a series of questions was the part where the bridge engineer said the four eggs are on a steel beam, with no nesting material around them. There are no falcons in the world that bring nesting material to their nest. No sticks, grasses, wood bark; nothing. At the Sioux Energy Center we provide a nest box with pea gravel on its floor, which simulates a cliff nesting situation. Before humans came on the scene, Peregrines would search for a place on a cliff that provided a level, mostly dry surface with some gravel or soil within which they’d dig with their feet a depression, or scrape, so their eggs stayed in one place. The depression also allows the pair to more efficiently incubate all the eggs at once. So, how does a female Peregrine incubate her eggs when they are sitting on a hard, flat surface? How does she not break them with her weight? How does she get all the eggs (as many as 5) under her at the same time?

In my experience I’ve witnessed Peregrines in the “hard, flat surface” scenario be perfectly successful, and ones that were not. All birds have feathers on their bellies, as they have over most other parts of their bodies. During a nesting season, females of some species actually pluck their belly feathers so their warmer skin is against their eggs and young chicks. This mostly featherless patch is called the brood patch. In my experience observing Peregrines, the females don’t pluck their belly feathers. This could be so they can keep their eggs and young chicks warmer with no nesting material to help insulate the eggs/chicks. If you are lucky enough to watch - especially the female - just before she settles her belly on the eggs, she fluffs up those belly feathers, thus enveloping most of the surface of each egg with those insulating feathers. The heat from her body (birds have a 104 degree average temperature, where humans are 98.6 degrees) warms the eggs and the feathers insulate.

Still, a female Peregrine on a flat, hard surface must have to prop her body up somewhat so her full weight isn’t on the eggs. A bird egg is very strong, but with all her weight on the upper side of the egg pushing the underside of the egg against the hard surface, you’d think cracks would form. Also, you would think she’d be much less comfortable for the 30 or so days of incubation. Her weight is probably supported with her whole foot. A bird foot includes the toes, the joint where all the toes meet and the bone that goes from that joint all the way up to the next joint, which is in essence the ankle joint. In my experience I’ve seen two females on flat surfaces incubate only one egg at a time, while the other eggs rolled around on the surface. When she’d leave for her brake, the male might incubate a different egg then the female was incubating, and when she returned she might incubate a different egg than she incubated before she left. You can probably guess that each of these nests failed. I’ve also observed two different Peregrine females successfully incubate all four of their eggs on a flat, hard surface, with all eggs hatching. The difference between the successful and unsuccessful females; hard to say. These are the questions that keep it interesting for me. You can bet I’ll again report on the Peregrine nest under the bridge at Hannibal, Missouri. In the meantime, our female should have chicks sometime over the nest 7 days.

5.24 - An Unfortunate Event

Hello All. I have some bad news. Over the weekend 18-19 May our 2 chicks died. In working with the person who runs the camera, it has been determined that the adult female stopped coming to the box. The chicks were still totally dependent on being fed by the female. The chicks don’t start getting strength in their feet and beaks, at least enough to feed themselves, until about 30 days of age. At that time they can also stand. All 3 things, standing over the food to be able to tear, having the foot strength to hold the prey in place, and beak strength, are very important in them being able to feed themselves.

The male cannot raise the kids on his own. Nature has given him the job of providing food for the female, and she brings the food to the box, tears it into pieces with her beak and feeds the chicks. When the female stops coming to the box, the male just isn’t capable of taking over the duties of feeding. Our camera man poured over camera footage from the weekend and found some video of the male sitting on the unhatched eggs. Of course, he doesn’t have the capacity to understand this futile effort. This bazaar behavior tells me something happened to the female.

Our female was 13 years old. In Ask Jeff 1 I spoke about how this is quite old for a Peregrine. There are so many things that could have happened to her; so many things that it’s useless to speculate. Over the 8 nesting seasons we have been able to get our viewers into the lives of Peregrine Falcons, I’ve mentioned how hard it is to lead a life in the wild, not just for Peregrines, but for all wildlife. Nature is seemingly cruel. Wildlife has to deal with predators, prey that can fight back, bad weather, let alone the obstacles we humans place in nature. Unfortunately we have to deal with this event, but I can safely tell you that there will be a thousand Peregrine nests in the United States this year that will fail, or have already failed. Again, this is just the harsh reality of nature. The bright side is there will be many more thousands of nests that will be successful, as our nest has been for the 7 years before the 2019 nesting season. Bottom line is the Peregrine Falcon population is still very strong, and with all the care and compassion we humans put into helping them be successful, there will always be Peregrines and much more wildlife for us and future generations to enjoy.

I think I can speak for our falcon cam team to say we all look forward to bringing you Ameren’s Sioux Energy Center Peregrine Falcon cam in 2020.

Author: Jeff Meshach, World Bird Sanctuary

5.21 - My, How Those Chicks Grow!

Hi All! We are rapidly approaching banding day, which is Tuesday, 21 May. My, how those chicks grow! They were about an ounce (28 grams) at hatching, and at 16 days of age (I write this on 17 May) they weigh about 12 ounces (336 grams). On banding day they will be 20 days old, which is the perfect age to band. Bird of prey chicks are altricial, meaning helpless for the first several weeks of life (the opposite is precocial, like duck chicks that can follow mom and swim within hours of hatching). I take advantage of this helplessness in that I don’t have to deal with biting, footing chicks when I collect them for banding. At 20 days of age they still aren’t walking, have no strength in their feet and very little beak strength. Yet, they are old enough where I can tell the difference between the males and females. Males are considerably smaller than females, thus I must use different size bands on each.

I got a question over the week! The question is when will mom stop brooding the chicks? In ASK JEFF 5 I wrote about the differences between incubating and brooding, and the reason why mom (and sometimes dad) must keep the chicks warm. As the chicks grow their bodies eventually get big enough where their core temperature starts to remain the same, which is 104 degrees F with most of our world’s birds. The more insulation there is around the cores of their bodies, the easier it is for their bodies to keep a constant temperature. This coupled with those amazing feathers, which are the world’s best natural insulation, our Peregrine chicks start to regulate their own body temperatures around 10 days of age. At 16 days old, which they are this day that I write, and with the temperature being in the low 90’s, there is no need for mom to do any brooding. Even if the temperature dipped into the 50’s tonight, the chicks would be fine without extra warmth from mom.

I’ll write to you next week right after banding day.

5.9 - Eight Days Old and Going Strong

Hello all! Today (5/9) our 2 chicks are 8 days old. Especially Dad falcon is busy bringing in prey for mom to feed to the ever growing chicks. As I write this I see Mom is busy brooding (I explained brooding in the last Ask Jeff) because the temperature is cool today, with also a little rain. Her position in the box is much different than it was a week ago and beyond, when she had very small chicks or just eggs. The chicks grow so fast that they make Mom have to stand up more as she keeps the chicks warm under her.

Fast growth is an understatement when speaking of chicks. In a mere 50 days the chicks will be fully grown. That’s going from weighing about an ounce and a half (45 grams) at hatching to males weighing about 28 ounces (800 grams) and females weighing about 50 ounces (1,425 grams).

You may ask why the females are much bigger than the males. There are several theories on this phenomenon. Some say males are smaller for better agility when trying to catch prey, especially during the critical time of incubation and young chick brooding. The male does almost all of the hunting for the female and then the young family.

Some say the female is larger than the male for nest defense. If the body is bigger it is thus more intimidating to would be egg/chick stealers. Still others say the female is bigger to be able to produce the clutch of eggs. The eggs take a lot of nutrients from the body, and if the body is bigger it should be able to more easily produce eggs and still leave plenty in the tank for other bodily functions.

A female bird’s body has another little secret to help with egg production. Birds that fly have hollow places within the larger bones. With flying being one of the most strenuous exercises in nature, having hollow bones helps save weight and makes for a lighter body more easily kept aloft. Females have the ability to grow medullary bone within the hollow spaces. Medullary bone is small bone spurs that grow from the bone surfaces within the hollow spaces. It grows over the non-breeding season, and during egg production the spurs decrease in size as the eggs are produced.

Still no questions from our viewers. I miss your questions! Please write them in and I’ll get right to them on the next ASK JEFF.

5.3 - We Have Hatching!

falcon baby sitting with eggs in a nest. falcon mother feeding baby in nest. Falcon mother snuggles with two babies.

Hello All.  The day has come. We have hatching!  One of our team members saw the first chick May 1.  With the current rainy and somewhat cool weather our female is sitting very tight on her new family, but on the morning of May 3 I finally saw the next generation – we were even able to grab a few photos.   When she got up to let the male take over brooding duties, I saw two chicks.  For those who watched last year, you may remember we had two then.  She had five eggs, and why only two hatched we will never know. However, with her and the male’s old age (13 and 15 years old respectively), it could explain lack of nesting productivity.

When a bird is keeping eggs warm, it’s called incubating. When a bird is keeping chicks warm, it’s called brooding.  It’s very important to keep the young chicks warm because birds can’t regulate their own body heat at first. They are much more like their reptilian ancestors (reptiles are cold blooded) until they get to be a certain size and grow their downy feathers to help insulate their small bodies. If you watch the Peregrines on a daily basis, you’ll see mom brooding the chicks a lot over the first 5-10 days. After the 10th or so day, and/or if the temperature warms into the 80’s, mom will start spending less time brooding because the chicks will start to regulate their own 104 degree F body temperature.

Our banding day is scheduled for May 21.  We turn the camera off that morning until our activities are done. Then you’ll see the new “jewelry” on the chicks. I like to band the chicks at 20 days because then you can easily tell the difference in size between the males and females.  Females are larger than the males, which translates to a different size band for each.

I’m ripe for answering your questions, especially now that the chicks have arrived. Talk to you next week!

Alert Info