Falcon Camera Questions

Have a question about peregrine falcons?

Send your question to Jeff Meshach at the World Bird Sanctuary! Your question along with Jeff's response may be posted here - so check this page often when you view the nesting falcons.

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Questions from 2014

June 23, 2014
From Jeff: Hello everyone!!

How are the chicks doing?
My, how time passes so quickly! Seems SiouxZee was just laying her first egg only last week. She actually laid her first egg on March 21, and that's the day the camera went live. That's almost 3 months of Peregrine Falcon Cam bliss.

I am happy to tell everyone that the 3 remaining chicks are flying well now. The Sioux Energy Center staff sees and hears them now and again, as they further develop their flight skills and beg for food from SiouxZee and Coal. The kids stay together loosely, sometimes chasing each other in the airspace over the plant. Wildlife siblings of most species seemingly play with each other as they grow, the theory being they are developing their skills to better survive when they leave parental care. As much as I stay away from anthropomorphism, which is giving human attributes to wildlife, I sometimes can't help but think the babies are playing with each other for the shear fun of it (but you didn't hear that from me).

I mentioned the plant staff can hear the babies. I can vouch for peregrines having an incredible set of lungs, since I've had many a defending-her-nest female yelling at me just a few feet from my head. When the youngsters see a parent, especially if the parent has prey, they immediately start to food beg, which is a high-pitched and much repeated yak coupled with very rapid wing beats, even as they fly out to try to grab the prey from the parent. Sometimes the parent makes the baby(s) chase them before giving up the prey. Sometimes the parent gives a chick prey that is still alive. Chasing and grabbing prey is an innate behavior (a behavior the chicks are hatched with), but the parents will still present chicks with live prey so the chicks have to kill the bird themselves. Seems cruel, but the act helps the chicks learn while still under parental care.

Someone sent a picture of one of the babies resting on an I-beam, with its left wing flopped over the edge of the beam. The person asked if the baby had a medical problem. I'll answer that with another question, and this question is especially directed to those with children. How many times, when your children were young, did you creep into their rooms and find them in sleeping positions that defied the logic behind even the most twisted pretzel? Same thing goes with sleeping or resting peregrine babies. I've seen our babies with both legs extended out behind them, one or both wings extended and their faces planted in the nesting box gravel as they snoozed away. In short, there was nothing wrong with the floppy-winged chick. It was just weirdly resting.

In another month or so, our chicks will disperse, probably on their own, but the parents could also chase them away, for once the nesting season hormones leave the parent's bodies, they consider even their own chicks rivals to their territory. It's anyone's guess as to where the youngsters will go. Peregrine in Latin means "wanderer," so our chicks could wind up in South America by autumn's end, then migrate back next spring to anywhere in the US, Canada, or even the Arctic, as they try to find their own territories. Yes, sad to not be able to see them on a daily basis, but exciting to think about what they could be doing and where they could be in the western hemisphere.

As I sign off for the 2014 nesting season, I must thank the Sioux Energy Center Falcon Cam team. What a great bunch of people to work with, and I very much look forward to working with all of them again in 2014. I also want to thank all of you, with your stimulating questions and your compliments. Have a great summer, fall, winter, and I'll write to you next spring! Jeff.


June 12, 2014
From Jeff: Hello everyone!

The chicks are spreading their wings!

One of the statements from questions I received last week was, "Watching the chicks jump from box to I-beam and back, and all their flapping, makes me a nervous wreck! And none of the chicks listen to any of my lecturing." This made me LOL, and I thank the person for adding the humor to the times we are in, regarding "our" babies. This person, watching a box. In a way I'm nervous, too, but all I have to do is think back to the natural cycle of things, the fact that these youngsters are preparing for the journey to take their place in their own territories one day, and the nervousness is replaced by excitement.

I band peregrine babies at several other nest sites in the St. Louis area, and last week I got my eyes on the Clayton, Missouri, adult female peregrine's band as she landed close to her kids. I had just put her 3 babies back in the nest after banding. Getting a band number from a wild, living peregrine and knowing I was going to find out exactly where this bird came from, gives me a high beyond belief! Turns out this female was banded on June 2, 2009, by one of my colleagues here at WBS (I couldn't do the banding that day because of prior commitments). She was one of 5 chicks that were raised by the pair nesting on the AT&T building that year. As nervous as we all might be about the fate of "our" chicks, I hope you can all think of this particular paragraph and find some peace.

The first flight these birds take is like the first steps a human baby takes...awkward. If they go all the way to the ground, where they would be vulnerable to predators like raccoons, you can bet the great people at Ameren's Sioux Energy Center collect them and take them back up close to the nest. As I have stated before, we don't want to interfere with nature, but when it's easy and safe enough to get the kids out of danger, we will.

It's incredible how fast the chicks learn to use their wings. The second, third and flights beyond get better very fast, and within 3 or 4 days they are flying around the plant almost as well as the adults. However, catching other birds for their food, and mind you those prey birds are zipping and darting to stay away from their sharp talons, is a whole other story. After fledging, the kids stay in the nest vicinity and are fed by the parents for up to 6 weeks. The youngsters are boisterous, especially when they see Coal or SiouxZee flying around with prey. Any of the kids that see this fly out to greet...well, more like steal...the food from the parent, and then fly away to a secluded place, so another sibling doesn't try to steal the food from them. Nope, there is no sharing between the siblings in the real world.

Over the 3-6 post fledging weeks of parental care, the kids gain the flight skills to catch prey on their own. They will leave the area on their own, or sometimes the parents, eventually considering their own chicks rivals in their territory, chase the "freeloaders" away.

On final question to answer...someone asked what SiouxZee and Coal do during the non nesting season. At the latitude the St. Louis area is positioned, winters aren't harsh enough and prey is abundant enough that they just stay on their territory around the Sioux Energy Center.


The camera will be shutting down very soon, since once the chicks leave the nest they rarely go back. However, I'll be back next week with the season wrap-up. Hope everyone has a great weekend!


June 5, 2014
From Jeff: Hello to everyone!

What about the chick that fell?

Almost all of the 77 emails for "Ask Jeff" over the last week pertained to the chick that fell from the nest late last week. I am sorry to say the bird was found dead below the nest Tuesday morning. It fell about 160 feet. There was an extensive search for the bird over the days in between its fall and Tuesday, and speculation was it fell only 8 feet to the grating below the nesting box, since both parents were observed spending time there for 2 days after it fell. However, the bird fell in a place on the ground where it was hard to see. 

For those that didn't see the video, this particular chick hopped to an I-beam in front of the box (this was a surprise to me because all of the chicks were so young). Then, SiouxZee flew into the box with food, and of course the bird on the I-beam saw this and tried to hop back into the box for its share. When it hopped, it didn't quite make it to the front edge of the box. 

Folks, in the real world of nature, 60 - 80% of all baby birds die before their first year of life. Some of those deaths are from natural causes, like predators, a first awkward flight that takes them into water or falls. Some of those deaths are because of humans, or human-made items, like cars. As much as we get to personally know SiouxZee, Coal and their chicks because of this great thing called the Nest Cam, their situation is still "the real world of nature." Of the several thousand nesting pairs of peregrine falcons in the United States that will never have a nest camera on their nests, the same unfortunate things happen to them, too. In the grand scheme of things, if all baby birds survived to adulthood, there would be such an imbalance in nature that the natural cycle of other things, for example a bird's food source, would become unbalanced or depleted to the point where other wildlife would negatively be affected. Nature seems to have a plan. Sometimes we humans can predict it, but most of the time we can't. 

I hope everyone continues to watch the surviving 3 chicks until they leave the nest and try to take their place in our world. I know I will. I'll write to everyone next week!


May 29, 2014
From Jeff: Hello to everyone!

What actually happens when you band the chicks?

Banding day, which was May 23, couldn't have gone more perfect. I climbed to the box and removed the chicks at about 8:30 a.m. Of course, SiouxZee objected, but as usual, her objections were all verbal, which was good for me. I have never been struck by any of the adult peregrines while I was removing or returning the chicks, but of course, I take precautions, like wearing a hard hat, protecting my neck with a thick collar and my back and arms with thick material.

The chicks were quite healthy, and this year we had three girls and one boy. You can always tell the males from the females because the females are bigger. One of the reasons I wait until the chicks are between 20 - 25 days of age is to make sure I'm placing the correct sized bands on the birds, and at that age the females are already considerably larger than the males.

I placed a United States Fish and Wildlife Service band on one leg, which is a light weight aluminum band with a series of numbers on it. On the other leg I placed a colored band, with black field over a red field and within each field are different letters and numbers. These colored bands are much more easily seen on the leg, and therefore can be read more easily from a distance. So, any observer at the right time and place can get a band number, and if the band is reported, then we biologists can find out how far the bird has traveled and how old the bird is. For instance, we know SiouxZee is a 2006 hatch from a power plant in south central Iowa because of her black P over green 93 colored band.

We also extracted a small amount of blood from each chick for chemical analysis. We are not worried about anything the chicks could have picked up from the Sioux Energy Center, since most power plants in the United States have a pair of peregrines nesting in them, and these power plant peregrines produce healthy chicks every year. We are more concerned about human made toxins the birds could be picking up from their prey. Peregrines eat birds, and many of the birds they eat migrate long distances, literally in between continents. Since the human presence is found all over the world in one way or another, and in the most remote places, any toxins found in the blood could alert us to problems and help us save the species. just as the species was saved from the pesticide DDT long ago.

I want to remind all our nest box viewers that as the chicks grow, they will start to leave the nest. The nesting box is supported by several metal I-beams, which are easily wide enough for the youngsters to jump to and leave the camera's view. Last year all four chicks left the camera's view and got to the back of the box where they couldn't be seen. Then one morning, SiouxZee flew to the box with food, and all the chicks raced into view, jumped into the box and enjoyed a good meal.

May 23, 2014
From Jeff: Hello all!!

Will you be attacked when you remove the chicks from the nest for banding?

Someone asked if SiouxZee and Coal will be attacking me as I go to the nesting box to remove the chicks for banding. Especially SiouxZee will be buzzing by me quite closely, probably within 2 - 3 feet. Peregrines have very loud voices, and the doplar affect I experience is quite amazing. When any animal defends anything, they use threatening behaviors and loud voices to make the menace leave, since no animal (including humans) wants physical contact that could mean injury and death.

 There have been many peregrine banders over the years that have actually been struck by the female, which is the main nest defender for all birds of prey (one of the theories why the female is larger than the male). I wear a hard hat, and on the back of it I've drawn a face, or at least two big eyes and a mouth full of teeth. When a human, or any predator considered a threat, looks directly at a bird, the bird gets nervous and usually flies away. With SiouxZee seeing the face on the back of my helmet, there's more of a chance she won't strike because she thinks I'm looking at her and therefore keeps at a distance. I have visited many peregrine nests where there was a chance the female could strike me, I've worn the helmet with the face on the back, and I've never been struck. Let's hope my luck holds out!

Speaking of vocalizations, someone asked if the mouth movements the chicks show when an adult brings prey to the nest means the chicks are vocalizing. Yes, the chicks have a hunger scream, and they are very loud, too.

Someone also asked if the chicks and the parents, with all their preening, are doing it because of parasites. I have visited many peregrine nests, and I've never seen any feather lice or mites, and I've never felt any crawling on me after handling the chicks. Birds take meticulous care of their feathers, because without them or with poor feather conditions, they could die. The adults are molting, or losing old feathers then growing in a lot of new feathers right now. The babies are growing in all their feathers. In a nutshell, the new feathers grow above the skin within a sheath, and the birds preen off the sheath so the feathers spread correctly for insulation purposes and so that the feathers resist air during flight. A large part of any chick's day is spent preening their new feathers.

May 16, 2014
From Jeff: Hello all,

What about the smallest chick?

Did continue to receive some questions about the unhatched egg. Any unhatched eggs usually get pushed to the back of the nest box or ledge (if it was a wild pair on a cliff), and it will stay there until nature finally degrades it and its shell pieces become part of the substrate. I will collect the egg when I band the chicks on Friday, May 23. We'll make two small holes in the egg, one at each end and allow the liquid to seep out. If there's something more solid in the egg, like a partially developed chick, then the egg will have to be broken to see how far along the chick was before it died. There could be many reasons the egg didn't develop.

There have been several questions about the smallest chick. For every year we have had this peregrine pair on the cameras (3 years now), there has always been a smaller chick, probably the last hatched, and in all the years, it has survived just fine.

The larger chicks do end up getting more of the food, but SiouxZee and Coal are great hunters and many times they bring food to the nest when the largest chicks are full, so the smaller ones do get what they need to continue to grow. Another reason there could be a smaller one or two is that the males are smaller than the females. This is true with all birds of prey. Yes, there's a chance the largest ones could get all of the food, and a chick or two could end up dying, but this is the way nature works. As long as there's prey for the parents to catch, and the parents are good at catching it, usually all the chicks survive to fledging, or their first flight from the nest.

Someone else observed that many times an adult will be in the nest box and just be standing there with the chicks seemingly not responding to the parent. Especially on these cooler mornings, SiouxZee is making sure the chicks aren't showing signs of needing to be brooded or kept warm. Altricial chicks, or chicks that are hatched helpless, need extra care and protection at the nest. All chicks can't regulate their own body temperature until they get to a certain age and size. So, SiouxZee, and sometimes Coal, stands over them looking for signs that the chicks may need to be brooded and, if needed, will cover them with her body and wings to keep them warm.

The chicks are about 14 days old now, and once we get back to normal May temperatures, SiouxZee will spend less time, especially during the day, brooding the chicks and definitely more time hunting to keep up with their ever growing appetites.

May 8, 2014
From Jeff: Hi folks,

What about the unhatched egg?

A lot of good questions are coming in, most of which center around the unhatched egg. Before I get to that, someone observed SiouxZee, as the eggs were hatching, eating a membrane from inside the egg shell. I actually got to see this, too. This membrane, and sometimes little pieces of the egg shell, are eaten by the female because especially the membrane is nutrient rich. Egg production by the female's body depletes her body of many nutrients, especially calcium. Nature has helped the female bird's body over the millennia by creating tiny bone spurs that grow into the hollow bones of birds' bodies, and these bone spurs are called medullary bone. As the eggs are produced, medullary bone becomes smaller and even disappears. Over the non-breeding season, the bone spurs reappear, so the body is ready to produce eggs for the next nesting season. Isn't nature grand!

As most of you already know, one of SiouxZee's 5 eggs is way overdue for hatching and will most likely not hatch. All of the eggs usually hatch over a 2-3 day span. SiouxZee's first egg hatched on May 1 this year. There could be many reasons an egg from a clutch doesn't hatch. The reason could have been internal. Maybe sperm and egg didn't meet up before the shell was laid down inside SiouxZee's body. Maybe a hairline fracture of the shell caused bacteria to get into the egg and do damage to the developing chick or the yolk, the developing chick's food supply. We will probably never know the reason.

Through the chicks jostling around in the box, the egg will just get pushed off to the side, and I'll collect it when I go to collect the chicks for banding, which is going to be the morning of May 23. Unless there is a dead chick inside, I'll make a small puncture at each end of the egg and with air force out the liquid contents. The World Bird Sanctuary will use or display the egg shell for educational purposes. Our federal permits allow us to do this.

As I did last year, I want to make sure all readers know there could be a chick that dies. Chick deaths happen in nature all the time for many, many reasons.

If a chick dies, there's nothing we can do about it. My visiting the nest to try to save a chick puts me at risk, since the nest is 160 feet off the ground. I only want to visit the nest once. With SiouxZee and Coal's nest/egg/chick care record, I'd be surprised if any chicks die. I've known the pair since 2011, and over that time 18 out of 19 of their eggs have hatched, and 14 of the 18 chicks have fledged (made their first flight) successfully. I know we will all watch intently as this year's 4 chicks develop and leave the nest, and through the hard work and vigilance of the guy that works the camera (I thank him very much!), we'll get to see some great things.

May 1, 2014

From Jeff: Hello, everyone!

How soon will all of the chicks hatch?

The first chick hatched this morning! As we humans time things, the first hatching was 2 days late. However, nature has her own time table. Either way, we actually have pictures on the website of the baby as it is still in half of the egg shell that it is emerging from (see Eggs in Nesting Box). Getting these pictures is quite rare, for even if you can time it correctly, chicks hatching usually happens under the female as she incubates the rest of the eggs or broods the other chicks that have recently hatched. Brooding is the term for the female, and sometimes the male, as they keep the babies warm. Young birds are more like reptiles in that they can't regulate their own body temperatures, so mom and dad have to help until they get to be a certain age and size.

As SiouxZee sits in her box 160 feet up the side of the main stack at the Sioux Energy Center, I can now contemplate the day I'll band the babies. It is best to wait until the chicks are 20-25 days of age. Females are considerably larger than the males, and at the dates mentioned, it will be easy for me to make sure I'm placing the correctly sized bands on each bird. Also, at the aforementioned age range, the babies still don't have the grasping power in their feet that the parents do. This fact makes it easier for me, since the babies aren't trying to grab me with their feet as I remove them from and then return them to their nest during the banding process. The tentative date for banding is Friday, May 23.

In the coming weeks, you will have even better chances of seeing Coal bring food to the box for SiouxZee to tear up and feed to the chicks. Their appetites are never ending, and the bigger they get, the more food they need. Everything about the chicks grow, includuing all of their feathers. Of course, it's the only time with most birds where all the feathers grow in at once. In the coming years, the chicks as adult birds will molt, or lose old and then grow in new feathers, in a sequential fashion, so not as much food is needed to replace feathers.

In 2011, 2012 and 2013, SiouxZee had 5, 5 and 4 eggs respectively. All of them hatched. I'm sure we all wish her and Coal the best in hatching the remaining 4 eggs this season! All should be hatched in the next 24-48 hours.

April 28, 2014

From Jeff: Hello, everyone!

Where does Coal sleep? I see SiouxZee sleeping in the nesting box as she incubates the eggs, but is Coal nearby?

All day active birds of prey, within a size range, get pretty secretive about their sleeping quarters. They sleep in a place that makes it hard, if not impossible, for them to be attacked by night predators, especailly Great Horned owls. Peregrines are definitely within the size range where Great Horned owls consider them just another item on their menu.

Coal probably sleeps high on a structure within the Sioux Energy Center complex, which would keep him out of the reach of raccoons, and maybe even inside a secluded hole, where a Great Horned owl would not see him.

April 21, 2014

Answers from Jeff 

What is the substrate used in the nesting box? 

Hello, everyone. Yes, if you want to call SiouxZee's incubation boring, I guess I would understand. When you think about it, though, what perseverance it takes to sit almost motionless for about 22 out of every 24 hours for 30 days or more! 

Yep, she gets "waited on hand and foot" by Coal, the male of the pair, but when I think about sitting so long for days and days, I can only think of muscle cramps and body aches and pains beyond belief. More power to the female peregrine! 

Someone asked what the substrate is in the nesting box, and what substrate is used in the wild? Peregrine falcons, as well as all of the world's falcons, do not make a nest. Some of the smaller falcons may use an abandoned stick nest that was built by another kind of bird. The American Kestrel, our country's smallest falcon, nests in tree cavities and adapts readily to a nesting box anyone can make and place appropriately (you can find plans for these nesting boxes on the Web). 

Before humans came on the scene (and even today), peregrines nested on cliffs, finding an adequately sized crevice with a gravel floor. The female scrapes a depression in the gravel with her feet and lays her eggs within the depression so the eggs don't roll around. On the bottom of the human made nesting box, we place pea gravel. Pea gravel is perfect in that it is easily moved around by the birds to make a scrape - and it drains very well, which helps keep the eggs dry.  


April 11, 2014

From Jeff: Hello, everyone! 

What about life expectancy of peregrine falcons in the wild? 

Because of the bands on their legs, and having the peregrine falcon cam, we know the exact age of both SiouxZee and Coal. As a refresher from last year, SiouxZee was hatched in 2006 at a power plant in south central Iowa, and Coal was hatched in 2004 at Ameren Missouri's Labadie Energy Center. (I got to put the bands on Coal and his siblings that year...small world.) 

This puts both birds at about middle to late age. If peregrines survive their first year of life, they have a good chance of living 12 - 15 years in the wild. Knowing this, I expect SiouxZee to have 2 - 3 more years of good productivity, laying 4 or 5 eggs with all having a good chance of hatching, and then her productivity will probably decline. She may start having 3 - 4 eggs, and maybe 1 or 2 won't hatch. 

Peregrines are like humans in that as their bodies age, things start to not work as well as when they were young. The same goes with Coal. 

Peregrine age also effects their ability to defend their nesting territory. There are so many peregrines in the environment now, I'm sure our pair has to fend off challengers many times during a year, especially during migration times (early spring and autumn). 

One day SiouxZee or Coal may suddenly disappear, and we would probably see a replacement female or male. The territory our pair possess is a good one, with the major flyway of the Mississippi River right under their beaks. This means there are a lot of prey birds moving up, down and across the river, so plenty of food for Coal, SiouxZee and their kids. If either bird falls out of the picture, it's almost a definite another will take its place and continue to nest in the box. 

Earlier I mentioned "if peregrines survive their first year of life." Sixty to 80 percent of all birds hatched in any one year die before they reach one year of age. Life in the wild is extremely hard! Once a peregrine fledges (leaves the nest and eventual care of its parents), it may not be able to catch enough food to survive. As fast as peregrines are, almost 70 mph in level flight and a record 261 mph in a dive after prey, they still have predators. At a year of age, in theory, "they've seen it all," so there's a better chance of catching more than enough prey to survive, evading predators and man-made hazards. 

In the meantime, SiouxZee and Coal have a great chance at being successful for the fourth year in a row, with 5 eggs in the nest due to start hatching April 29!

March 31, 2014

There were a lot of questions about the number of eggs and incubation period. 

SiouxZee and Coal's first egg was laid on March 21, 4 days later than last year and 11 days later than the year before. 

The lateness could be for many reasons. One of the best reasons is perhaps because of the harshness of the winter. With such a cold winter, all the way up to mid-March, all birds could put off laying for days to, in theory, give their eggs a better chance of surviving to hatchings. 

About once every 2 days, SiouxZee laid an egg, and as of March 29, she laid her fifth egg. Last year she had 4 eggs and in 2012 and 2011 she had 5 eggs. From 2011 through 2013, all of the eggs hatched. We'll keep our fingers crossed that her 5 eggs this season will successfully hatch as well. 

With her last egg laid, SiouxZee will now faithfully incubate her eggs, with a little help from Coal, through and including the last egg hatching. We should see the first egg hatch on April 29. 

It takes about 30 days for a Peregrine egg to hatch. Peregrine parents don't faithfully incubate the eggs until the last egg is laid, the theory here is if mom started faithfully incubating as soon as the first egg was laid, the first 2 kids hatched would have such a head start in development that they would eventually muscle out the smaller, younger chicks and get all the food brought in by the parents. Sporadic incubation until the whole clutch is laid helps ensure all the chicks hatch in about 2 days and all are roughly the same size with an equal chance of getting the food mom and dad provide.  

Several of you asked if last year's chicks have been seen. 

To my knowledge, none of last year's chicks have been spotted by anyone in the world, and I am serious when I say, "world." In Latin Peregrine means, "wanderer," which describes how far these fastest of the world's animals migrate. It would not be out of the question to have a band reported from the southern tip of South America, anywhere in Alaska or even the northern most tip of Greenland. 

However in December 2013, we did get a band report from a chick hatched in 2012! Someone took his picture near Lock and Dam 26, which is only about 10 miles downstream from the Ameren Missouri Sioux Energy Center.



Questions from 2013

June 18, 2013 

Any sign of the the peregrine falcon family? 

At last check, all the fledgling chicks are doing fine. The parents are still feeding them, and I'm sure the workers at the energy center can hear the youngsters scream when the parents bring food into the vicinity of the box. 

When the chicks see a parent, even if it doesn't have prey, they will fly up to greet the parent in anticipation of grabbing food. The chicks are always hungry, so the first chick to make it to the parent will get the food. I'd bet the chick with the food gets chased by the other chicks, and if the first chick isn't fast enough, the others will steal the food. 

A couple of you said you recently saw an adult at the box. If a parent comes in with food and none of the chicks are within sight, the parent may fly to the box out of habit. 

How many clutches do peregrine falcons have a year? Are they mates for life? 

Raising even one young peregrine is a big-time expense for the parents. With SiouxZee and Coal, courtship starts mid- to late-February; the first egg is laid in mid-March; the first chick hatches mid- to late-April; the kids fledge in early June and they don't become independent of the parents until early to mid-July. That's five months. If the parents started the whole process, say in mid-July, the second set of kids wouldn't be fledging until about mid-October. That wouldn't be enough time to beat cold weather. Also, the timing of fledging coincides with young prey birds fledging, so the peregrine youngsters have a large prey base. In mid-October, the odds of them catching easy prey would be way less, so the probability of the chicks surviving would be way less, too. 

Peregrines do mate for life, but if one of the pair dies, it is replaced quickly. This scenario probably happened this spring with a peregrine pair in Kansas City. For reasons of territorial defense, it is to the surviving mate's advantage to secure another mate as quick as possible. 

Will SiouxZee and Coal come back next year? 

We do hope SiouxZee and Coal return next year, but nature is quite harsh, and there's no guarantee one or even both will be back. If one or both aren't, I believe there's a good chance the territory will be occupied again. With all the prey birds that travel up and down the Mississippi and with such a great box to nest in, the territory is prime real estate for peregrines. We will have to wait and see. 

Thanks for the questions!



June 14, 2013 

Another incredible ride on the Sioux Energy Center Falcon Cam! Many of us got to see fantastic footage of the parents, eggs and chicks, from March 17 - when the first egg was laid - until now. To watch, talk about, band and write about peregrine falcons gives me a feeling that's hard to describe. I can only thank all those responsible from World Bird Sanctuary, the Missouri Department of Conservation and Ameren Missouri for bringing this great experience to my computer. 

I am already looking forward to watching and writing about the 2014 nesting peregrines at Sioux Energy Center. Will SiouxZee be the mom next year? Will Coal be back to take up his fatherly duties and provide his female and kids with food? Nature will continue to run its unpredictable course and we shall all find out. 



June 11, 2013 

Do peregrine parents teach their chicks how to hunt? 

Hunting behavior is innate, meaning baby raptors don't have to be taught to do it by the parents. They just grow up knowing, and this was proven back when the peregrine was an endangered species. Many organizations, including World Bird Sanctuary, released baby falcons that were hatched and raised in captivity from a hack box, which food was placed in on a daily basis. Peregrine babies cannot catch food upon fledging from either the hack box or the nest, but parents continue to provide food for the babies in the vicinity of the nest, and the babies would come back to the hack box for food as they developed their flight stills. 

There have been many accounts of the parents bringing a prey item that's still alive. The chicks will fly in to take the food from the parent bird, and when the youngster first grabs a prey bird that is still alive, they usually drop it like a hot potato. Of course the young falcon wasn't expecting the prey item to still be moving, but hunger helps the kids get over their fear of live prey quite quickly. It takes two to five weeks for the babies to develop good enough flight skills to catch their prey. I had the privilege of observing our first hacked peregrines in 1985, and watching them go from their first awkward flights to the sleek, efficient predators they are was incredible. 

Are the chicks vocal? 

Some of you observed the chicks' beaks moving rapidly, especially as mom or dad brought prey to the box. Yes, the chicks are very vocal. To have your head close to the box as a parent brings in prey would cause hearing loss after only a few prey items. 

Are the chicks vulnerable to ground predators? 

I never count out a raccoon raiding even the most inaccessible nest, since they are so smart and can problem-solve very well, but the nest cam box is 180 feet off the ground, and unless a raccoon figured out how to work an elevator, there is no way a raccoon or any other mammalian predator could get to the box. However, great horned owls and golden eagles can and will kill and eat peregrines chicks. With all the lights on at night at the energy center, the parents would probably see a great horned owl as it tried to approach the nest, and would attack to drive it off. There are no nesting golden eagles in Missouri or Illinois as far as I know, so hopefully no worries from that predator. 

The only other predator that could raid a vulnerable nest would be a black rat snake. They are terrific climbers and do eat bird eggs and babies, but again, the parents would attack and drive a black rat snake away. Attacks by any predator have been one of the theories on why baby birds grow so quickly. The faster they leave the nest, the better chance they have of surviving to produce their own kids.


June 5, 2013 

How do peregrine falcon chicks get water? 

Bird kidneys are much more efficient than mammalian kidneys. Just the water within the prey fed to them has enough water in it to satisfy their needs, especially since the chicks don't exert as much as their flying parents. 

What is the status of last year's chicks? 

There have been no band returns from last year's chicks, which hopefully means they are all surviving just fine. In June 2012, I banded three females at a peregrine nest in Clayton, Mo., about 10 miles west of St. Louis. On Aug. 14, 2012, one of the females was spotted near a power plant in Indiana, about 176 miles from where she was banded! One of the bands I place on the legs has large numbers and letters. This band can be seen from further away, giving an observer more of a chance to read the band and gain knowledge about a bird while it is still healthy and surviving in the wild. 

Thanks for the questions!



May 31, 2013 


Last year we had lots of calls and questions on where the peregrine babies went, because at this time a year ago the box was empty even though it was too early for the kids to fledge the nest. Since the babies hatched, the three males should take their first flights around June 10 and the female around June 20 (45 days old and 55 days old, respectively). 

There are many steel girders or beams in front and around each side of and behind the box. Last year the chicks got adventurous, left the box and hopped away from the camera view. During the first day of this, the mother peregrine flew into the box with food and the mystery was solved. The chicks came racing across the girders, hopped back into the box and took the food. Almost all raptors do what's called "branching," when they leave the nest and walk out to the branches supporting the nest. Maybe at the Sioux Energy Center we should call it "girdering!" 

Banding Day Videos 

Several asked about viewing the footage of the peregrine falcon chicks getting their bands.

View banding day videos. 

Thanks for the questions!



May 28, 2013 


A kindergarten class asked when the chicks will be able to produce babies of their own. A very good question! On average, peregrine falcons start producing babies when they are about three years old. There have been some cases where two-year-old peregrines produced babies, too. 

Thanks for the questions!



May 15, 2013 

Territory Size 

A question came in about territory size, and if placing more nesting boxes at Sioux Energy Center would attract more than one pair. The average territory size of a peregrine is roughly five square miles, but that number could be a lot larger, depending on prey availability. In theory, the more prey there is in an area, the more predators the area can support, and visa versa. However, peregrines can only tolerate another nesting pair so close. Then the line in the sand (or should I say air) is drawn. I know there’s another peregrine pair about three miles up the Mississippi on the Illinois side. Another pair is about seven miles upstream from that pair, on an Illinois cliff. Peregrines are fiercely territorial, and will attack other raptors species, including eagles, when the threat comes too close to their nest. 

Height of the Nest 

Someone asked about the height a peregrine nest must be from the ground. In my experience, I’ve a nest that is just 30 feet from the ground, and the highest nest I’ve seen is on the AT&T building, downtown St. Louis, which is 46 stories up! I don’t think there’s even an average I can give. If the location seems right to a pair, they will take advantage. 

More about Peregrine Chicks 

Another few questions were about predators of peregrine chicks, why both SiouxZee and Coal will try to pile all the kids under them during certain times of the day and how often the chicks are fed. All baby birds are more vulnerable to predators while in the nest. Many kinds of mammals and snakes will prey on babies in the nest, which is why baby birds grow so rapidly. The faster they can fly from the nest, the better chance they have of surviving. 

Until they reach a certain size, baby birds cannot regulate their own body temperatures. Birds are more like their reptilian-like ancestors as babies, so mom or dad must brood them, which means provide them with warmth from their bodies, especially when there are cool temperatures. 

The larger baby birds are the more food the parents must bring to the nest. Around 17 days old, the parents are probably coming in three to five times a day with food, but the following week will probably double the amount of food. Around 28 days of age, the babies will have quite a bit of strength in their feet, so you will start to see the parents bringing in food. One baby will take the item and try to get as far away from the others as possible to feed itself. You also may get to see the chicks fighting over food. 

Replacing the Camera 

The last question I want to address came from a school group who asked if the cost of replacing the camera was affecting us not repairing or replacing the camera. Please rest assured World Bird Sanctuary, Ameren Missouri and the Missouri Department of Conservation want all viewers of the Falcon Cam to get the best look possible at these avian miracles. We also want the birds and the workers that must approach the nest box to be as safe as possible. Taking the camera off its pedestal for replacement would take too long to accomplish, exposing workers to attacks from the parents and keeping the parents from their babies for too long a time period. When the weather warms up and the chance for condensation lessens, we should see a perfect picture of the family from dawn to dusk. 

Thanks for the questions!




May 7, 2013

Camera Issues 

We are experiencing problems with the camera at Sioux Energy Center. With all the blowing rain a few weeks ago, some moisture got into the globe that protects the camera lens. The solution to this - a small heater within the globe - burnt out. On May 17, the chicks will be banded a short distance from the nest. While this is happening, Ameren personnel will try to repair the camera. The camera lens is the worst early in the morning, but the sun warming the globe helps to clear up the moisture late morning. We apologize for this problem and will do our best to repair it. 

Egg Hatching 

Several had questions about the process of egg hatching. At about 30 days, the chicks are ready to emerge from the egg. All unhatched bird chicks are equipped with an extra point on the end of the upper beak called the egg tooth. The chicks use this to punch a series of holes (that eventually form a circle) at the fat end of the egg. Once the circle is completed, the end of the egg falls away and the chick emerges. Mom and dad only provide verbal encouragement; they squeak and twitter, which stimulates the chick to keep making the holes with its egg tooth. The tooth should disappear soon, but can now still be seen on the chicks when their heads are sillouetted against the dark back of the box. Once the egg pipps, or the first hole is created, the process usually takes about 24 hours. It's hard work for such a small being, and there are times where the chick stops and rests. If an egg doesn't hatch, the chick's movements eventually push the egg off to the side. All four eggs have hatched this year - two chicks hatched on April 26 and the other two on April 27. 

Leaving the Nest 

Another had a question about the timeframe between hatching and fledging, or leaving the nest. All birds grow very quickly, for while in the nest they are more vulnerable to predation. Male peregrines usually fledge at 40-45 days, and females 50-55 days. The smaller, more agile males gain their flight skills earlier, with one of the thoeries being they leave the nest first so the bigger females don't mistake their brothers for food! 

Chick Deaths 

Lastly, I want to brace everyone for the potential of chick deaths. Because of natural processes, whether bacterial, large disparity in chick sizes or many other factors, chicks do die in the nest. Last year we were able to watch all five chicks leave the nest. This year and in years to come, we may not be so lucky. We cannot interfere with nature. To try and do something for a chick that may not be getting as much food as the others could jeopardize the other chicks, and maybe even me! The nest is 180 feet off the ground, just being up so high is a risky situation. 

Eggs are laid two to three days apart. Usually a female bird will wait until the last egg is laid before she starts to seriously incubate. The wait helps make sure all the eggs hatch close to one another in time. If a bird has to incubate the first egg early, it may have a six- to nine- day head start on the last laid egg. Such a difference usually means the last chick or two hatched might get muscled out of food by the older chicks. This year, SiouxZee had to start incubating her eggs right as the first was laid because March was so cold. But as of this morning, all four chicks look healthy and happy, even getting a bite to eat when dad Coal brought in food. 

Thanks for the questions!




April 9, 2013 

Jeff, is there a pattern for the male falcon of when and what times he will feed or replace the female sitting on the eggs so she can eat? - Mark D. 

There is probably a pattern on when he relieves her at the nest while eggs or young babies are present. Eggs must be incubated constantly once the incubation starts. Baby birds are much like reptiles; until they achieve the size and down feathers to regulate their own body heat, they must rely on the heat from mom or dad. This "temporarily changing of the guards" pattern can be figured out by someone that could watch most of the day for a few days in a row. There probably is not a pattern for dad bringing food to the nest for mom, only because dad doesn't catch food consistently enough to show a pattern. For birds of prey, it has been estimated for every food item brought to the nest, there are 10 unsuccessful attempts to catch food. 

Does the mother falcon have to lie in a certain way so she doesn't crush or crack the eggs when she's incubating them? - Caitlin S. 

Mom rarely puts all her weight the eggs. She parallels her lower legs (called the tarsus) to the nest materials under her and spreads out her legs enough to fit all the eggs in between them, with probably an egg or two forward from her legs and an egg or two behind her legs. One of the theories of why females are larger than males in birds of prey is the bigger body more efficiently incubates eggs and broods young babies. 

March 27, 2013 

Hi Jeff, is this the same pair of falcons as last year? And if so, do they migrate south and then return to this nesting site, or do they spend winter here? - Robert L. 

It's a pretty safe bet to say that the Sioux peregrines stay on their territory year round. Adult birds and sometimes juveniles are seen periodically throughout the non-breeding season by Ameren Missouri's Sioux Energy Center personnel, either around the nesting box or perched near the energy center. Peregrines from further north definitely migrate south for the winter - sometimes all the way to South America. 

We weren't able to get the band number of the male last year, so I'm not sure if this male is the same one. We did get his band number earlier this breeding season and now know this male was hatched at Ameren Missouri's Labadie Energy Center in 2004. I actually put the band on that bird in June of that year. 

Thanks for the questions!


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