Peregrine Falcon Questions - Ask Jeff

mother perigrine falcon feeding her chick

Have questions while watching the falcon cam? 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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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! 


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.


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.


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.


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.


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!

Past Falcon Camera Questions

May, 22nd 2019


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 Portage de Sioux Energy Center Peregrine Falcon cam in 2020.

May, 20th 2019

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.

May, 13th 2019

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.

May, 5th 2019

Hello All. The day has come. We have hatching! One of our Peregrine Cam Team members saw the first chick 1st May. With the current rainy and somewhat cool weather our female is sitting very tight on her new family, but on the morning of May 3rd I finally saw the next generation. When she got up to let the male take over brooding duties, I saw 2 chicks. For those who watched last year, you may remember we had 2 then. She had 5 eggs, and why only 2 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 21st May. 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.

No one asked questions over the last week. I sure hope that changes, especially now that the chicks have arrived. I’m ripe for answering your questions, so talk to you next week!

April, 26th 2019

Hello Everyone! There were no questions asked last week, and with our female patiently incubating her clutch of 5 eggs, I skipped last week’s Ask Jeff. However, that doesn’t mean I didn’t have an interesting Peregrine Falcon experience over last week.

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 one side or the other. 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 4 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 2 days to continue their inspection, but once they found out the Missouri state endangered Peregrines were nesting there, they postponed their inspection until after 1 August (a special thanks goes out to MODOT for this postponement). The nesting cycle would be all over by that time of the summer, 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 defended 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 4 years at Portage de Sioux Energy Center the female has struck with her feet my helmet at least 30 times per nest visit, as she tried to shoe 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 4 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 Portage de Sioux 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 2 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 2 different Peregrine females successfully incubate all 4 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. Keep your eyes peeled!

April, 3rd 2019

Hello all! Our female, being 13 years old this year, has done it again. She’s managed to lay 5 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 26th. She laid her first egg on 18 March, and Peregrines usually lay an egg every 2 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 on 26 April.

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 number of days between eggs laid and egg development during incubation. If our female had 3 days between, say, egg 3 and 4, then the hatching date could be off by a day or 2. 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 2 days between the ages of each chick, the first 2 or 3 hatched would be bigger, stronger and would probably get most of the food, and the 2 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 fledgling (flying from the nest).

So far, I’ve had no questions to answer. Let’s get to it, folks! Put a challenging question out there for me to tackle. I look forward to any and all questions you may have.

March 18th, 2019

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.


June 26th, 2018

Hello all! Apologies for the lateness of this last of the 2018 Peregrine Cam season’s ASK JEFF. The team was trying to get the exact last day the chick was seen at or near the nest, and we came up with 7 June. During the last few days we saw her she was on top of the box and on the I-beams behind and to the left of the box. Whenever one of her parents came back with prey, they’d fly into the nest and the chick would come scrambling back to get her meal. During these later days the chick would just grab the prey and go someplace else with it. At the very least, she would turn away from the parent and spread her wings and tail out, hiding the prey from the parent. In the bird of prey world, this behavior is called mantling.

There were a couple great questions over the last 3 weeks!

A person watching adult Peregrines nesting in a box on the Throgs Neck Bridge that crosses the Hudson River in New York state saw 3 adults at the box (the box had young chicks in it), and the adults seemed to be getting along! As you might guess, the large majority of Peregrine pairs (and bird pairs) in the world do not tolerate any other adults in their nesting territory, and vigorously attack any Peregrine that comes into their territory. However, there are some cases of one adult male having two breeding females in his territory. The one instance I read about happened near Minneapolis, Minnesota. Through chick blood sampling it was proven that the adult male was the father of all the chicks. His two females nested in separate places, though. I personally would find it hard to believe that there were 2 females in the same box, or there were 2 males in the same territory with one female, but this is the thing about nature, folks. It is rare that you can be absolute about anything. If the person who wrote to me about the Throgs Neck trio would like to write again if he/she has gathered new information about these Peregrines, that would be fine with me.

Another person asked if/how we track the chicks. We have never placed any kind of transmitter on any of the 26 chicks that have been produced at Ameren’s Portage de Sioux Energy Center since we placed the nest camera, but with every chick we do place a colored band on one of the legs. These bands have two colored fields, one on top of the other. I’ve placed black over green, black over red and black over blue bands on the chicks over the years. Each colored field has letters and/or numbers within each field. The size of these numbers/letters and the colored fields each number/letter is in make it easy to see, especially with a good pair of binoculars or a spotting scope. Because of these bands I’ve gotten many band returns over the years, giving me information about chicks I banded, and I’ve given many colored band sightings to my Peregrine banding colleagues. These bands are how we know our male was hacked at a power plant in southern Missouri in 2006 and our female was banded at a cliff nest in Minnesota the same year. These bands may not be as good as a satellite transmitter on a bird, but we still are able to collect lots of information we otherwise wouldn’t know.

With the transmitters, the chicks have to be full grown because the transmitters are placed on the bird’s back using Teflon straps that make a harness. With the optimal banding age being about 20 days old, I could not put a harness on such a young bird because it still would have so much growing to do. To use a satellite transmitter you have to catch the full grown youngsters using falconry trapping methods. Maybe one day we will place a satellite transmitter on one of our young birds.

My, how time flies (pun intended) when you are having fun. The 2018 Peregrine Cam season saw some tragedy and also a miracle. With our living chick falling from the nest box at such a young age, most would have thought it would have perished. Yet, with the hard and timely work of the Falcon Cam team and the World Bird Sanctuary’s rehabilitation staff, we were able to nurse the chick to good health and get it back into the box fast enough where the parents still wanted to care for it. The miracle chick went through the rest of its nest life without issue and left the nest to destinations unknown. We all hope one day someone spots the band and we find our miracle chick has become part of a breeding pair somewhere else in the world. Thanks to all of you that wrote in with questions, to the rest that intently watched our Peregrine Falcons, and I look forward to writing to all of you in 2019!

June 6th, 2018

Hi Folks. I just looked at our chick, 6 June at 1:55 pm, and she was standing on top of the box! With all the signs she’s giving us, I’ll say again it could be anytime now she will leave the nest box forever. Several of you wrote in this morning saying the chick was gone. Maybe it is running the I-beams to the left and behind the box and then came back.

I’ve never seen the behaviors myself, but have read accounts of what Peregrine parents will do to coax their kids into taking their first flight. With their eyesight being so sharp, you know a Peregrine chick can spot one of its parents flying from literally a mile away. The chicks will also immediately notice if the parent they are looking at has prey in its feet. To make it even more obvious, the parents will fly close to the nest and even bank to whichever side that will make the prey in their feet even more obvious to the chick(s). With the chicks always being hungry, they can’t help but take that first jump to try to chase the parent with the meal.

Today our lone female chick is 44 days old. Her juvenile colored feathers are almost fully grown in. When the feathers are growing, each one has a blood supply going to it. When the feather is at full length, the blood supply stops. With Peregrine Falcons the first 2 inches or so of the fully grown, large wing and tail feathers is hollow. Partially hollow feathers are probably an adaptation for flight. The lighter the body, the easier it is to fly.

So much growth, whether it be feathers or the rest of the body, is the main reason young birds are always hungry. Once a bird has all its feathers it will never again have to worry, if you will, about growing in so many feathers in at once. Each feather on a Peregrine has a life expectancy of about 2 years. As tough as they are, feathers do have a shelf life. To keep a bird symmetrical as it flies, only the corresponding feather on each wing will molt, or be lost, and when those 2 replacement feathers are done growing in another 2 will molt, and so on. The bird can molt in 2 or more tail and body, or contour, feathers at once, since those feathers aren’t as important to flapping flight.

Now to your questions; someone asked about the life expectancy of Peregrine Falcons. Once they make it through their first year they can live to 15 or so years old. The first year of life is hard for any animal on the planet, with 60%-80% dying during this time frame. Once they gain a year’s experience in dealing with all nature has to throw at them, they have a better chance of living a longer life.

Another questions is whether birds remember a traumatic experience. With all the training I’ve done and seen done with birds, I know for sure that they remember a bad experience. At World Bird Sanctuary we keep all experiences positive when training, but if an individual has a negative experience, you can tell by behaviors afterword that they remember. The person who wrote the question pertained it to this chick falling from the nest at an early age. While this bad experience might have some baring on this chick leaving the nest, ultimately the need to fly will prevail, and she will take flight. One other thing; birds don’t want to fly, as we humans might think. Yes, to us flight would be breathtaking and symbolize freedom. To a bird flight is a means of transportation to food, a mate, water and leaving a nesting area when cold weather comes.

As I mentioned in the last ASK JEFF, once the chick leaves the nest I’ll write one final ASK JEFF for the 2018 Ameren Missouri Portage de Sioux Energy Center Peregrine Cam season. I’ll talk to you sometime soon!

June 5th, 2018

Hello All! Today our chick is 39 days old. I just finished watching her (1 June at about 10:15 am), and she was jumping quickly from nest box floor to front edge and then back into box again. After this seemingly strenuous activity, she plopped down on the box floor, and she seemed to be falling asleep. On these hot days and especially after getting a meal (which she probably did earlier in the morning), the chicks seem to want to nap away the heat of the day. Back in 1985 when I first started with WBS, I had the privilege of monitoring our first ever hacked Peregrine Falcons, which we released from a hack box on the then Pet Incorporated building in downtown St. Louis (this building is now the Pointe 400 building and has been converted to apartments….and by the way, has had a pair of Peregrines nesting on it for the last 3 years!). As a quick refresher, hacking is releasing captive raised birds of prey to the wild. Hacking had a major roll in bringing the Peregrine back from the brink of extinction. I can remember watching the 2 young Peregrines we released, after they had fledged from the hack box, laying down on a shady ledge and falling asleep during the hottest part of the day. Yes, we interns monitoring the young falcons found it hard to not do the same thing! As another refresher, the current adult male of Ameren’s Portage de Sioux Energy Center was hacked from a box in 2004 at a power plant in New Madrid, Missouri.

The only question I had over the week was asking about a strange behavior the female was exhibiting as she stood in the nest box along side the chick. The behavior was described as throwing her head back several times with her mouth opened. While Peregrines perform behaviors that even the best behaviorists have a hard time figuring out, I do believe I can explain this one. All birds have very efficient digestive systems that process food quickly so this food isn’t weighing them down very long. As efficient as their digestive systems are, the system can’t digest everything the bird swallows. With Peregrines eating mostly other birds, you might guess that as they swallow the meat and bones from the prey item, Peregrines will also swallow many feathers during the meal. Peregrines cannot digest feathers. As the digestive juices within the stomach dissolve the meat and bones, the movements of the stomach compact the feathers into a pellet that’s shaped roughly like an egg. About once a day, and usually in the morning, the pellet is regurgitated from the mouth. I get to see the nest floors when I visit nests to band chicks, and the floor is littered with pellets. Yes, you can take apart dried pellets to see what birds a Peregrine has been eating.

When a bird gets ready to “throw” a pellet the back of their neck arches up and their moth opens wide. As the pellet moves up the esophagus the bird will shake its head side to side to expel the pellet. We naturalists at WBS get to see this behavior all the time from the birds we handle on a daily basis. Sometimes the pellet doesn’t come up in one piece. When this happens a bird will throw its head in many directions, including over its back, to bring up the rest of the pellet. I believe the viewer with the question was seeing our female with a small piece of pellet somewhat stuck in her esophagus. No worries, folks. I’ve seen our mom several times since the day the viewer saw her, and she’s fine and dandy!

At 39 days old our chick could be leaving the box over the next 7 or so days. If she chooses to walk the I-beams our camera man will do his best to find her so we can keep watching. If she flies away from the box I’ll write one last ASK JEFF for the season. Of course, like all of you I’ll hope we get to watch her for as many days as possible.

May 21, 2018

Hello everyone! I’ll give you a quick refresher from my ASK JEFF 7, written Monday 14 May.

When I went to band the chicks last Monday, 14 May, both chicks were not in the nest box. One had fallen to its death and the other was on grating about 8 feet below the nest box. The living chick was brought back to World Bird Sanctuary’s Wildlife Hospital to make sure it hadn’t suffered any broken bones or other injuries when it fell. On Tuesday X-rays were negative, and for the next 3 days the chick was rehydrated and fed well. Yesterday afternoon I placed the bands on each leg.

This morning, 18 May, Mike Zeloski, long time WBS staff member and I took the chick back to Portage de Sioux Energy Center and placed it back in the box. Mom and dad were there still defending the nest, which was great to see. I climbed to the box and put the chick back in, all the while being pummeled on the helmet by mom.

The big event we needed to see was mom coming to the box and feeding the chick. If chicks are gone from the box too long, both parents could lose the drive to want to care for any chick. Within 15 minutes the female brought food into the box and fed the chick! We were ecstatic!

In the wild Peregrine Falcon world nature takes its tole on especially the chicks. Within their first year of life, 60% to 80% of all chicks will die. Living in the wild is a hard life. In this case we were able to reverse the trend. Regardless of how many times the female raked her talons across my helmeted head, it was so rewarding to let the chick slip from my hands and hop to the back of the box, turn around and hiss at me. I wished her (yes, the chick is a female) luck, did the same with mom, and we all got out of there to let the parents go on raising the chick.

A special thanks goes out to all who helped with getting the chick back into its nest box. You all rock!

May 15, 2018

Hi Folks. There were 5 of us WBS staffers that left this morning for the Portage de Sioux Energy Center, bright-eyed and bushy-tailed, ready to collect and band the 2 chicks in the nest box. I for one checked the camera Friday afternoon before leaving work and saw 2 chicks, as I expected, slumbering in the box in between meals brought in by mom. I didn’t check the box during the weekend.

This morning I was first to leave the safety of the structure that supports the large stack at the energy center. Again, as expected, mom was right there to “greet” me, diving in close and striking my helmet 2 times before I could get within the relative safety of the I-beams leading up to and supporting the box. I found parts of several prey items at 24 feet below the box. I’ve found many of these things over the years, so one more time, all completely expected. It was when I looked up at the grating just below the box that things started to seem wrong. There on the grating, about 12 feet below and behind the box, was one of the chicks. At 21 days old, the chicks are still quite helpless and definitely cannot fly. So, why would one of the chicks be so far from the box?

Rather than asking anyone questions, I climbed the ladder to get to the chick, stepped onto the grating and took the chick into my hands. It was certainly alive, but not completely well. As I examined it, Dawn Griffard, WBS’s executive director, got to the top of the ladder, and I handed her the chick. The mom Peregrine continued to swoop in and hit our helmets as I hoisted the crate up that would house the chicks as we took them to the building where we would band them. Also hoisted up was the ladder that would help get me the last 10 feet to the box, along with some safety equipment. After a few more minutes I hooked myself in and climbed to the box. I peered around its left side to find that the second chick was gone.

For the 45 seconds it took to look into the box mom peregrine stuck my helmet 5 times, so I ducked back down to the lower lever to assess the facts. We found out that early last Saturday afternoon a strong, straight line wind hit the energy center. The wind was strong enough to suck both chicks from the box. Just in front of the nest box it drops 167 feet to the ground, so we all agreed it was a miracle that this chick was somehow blown to the grating below the nest and survived. Upon further observation we were able to spot the second chick. It was on a ledge 100 feet below us, and unfortunately it was dead.

Because of the compassion we have for these noble birds, one cannot help but feel great sorrow when things like this happen. Of all the birds I have had the privilege of studying and working with in my life, Peregrine Falcons are my favorite. As much as I am grieving for the lost chick, my knowledge of nature lets me grieve only so long. As much as I love to watch the chicks grow and be able to see the incredible parents so up close and personal, I keep a certain objectivity about these wild birds because I know nature can randomly select in favor of tragedy. Yes, tragedy has happened to our Peregrine family, but there’s nothing anyone could have done about such a random act of nature (a big wind in this instance) coming in and taking one of the chicks. Of the many thousands of Peregrine nests in the U.S., it is inevitable that many of them will experience the loss of chicks, or even total failure, because of nature. I can console in reminding everyone of the 30 chicks our 2 set of parents have raised and fledged from this box.

About the surviving chick; the WBS team in attendance this morning was lucky to have within its ranks Bethany Spiegel, our rehabilitation coordinator. Her initial assessment of the bird showed only dehydration from lack of being fed, so we brought the chick with us to our rehabilitation hospital. The bird will be x-rayed the morning of 15 May to make sure there are no broken bones.

There are 3 scenarios for the chick’s future.

#1, there’s a chance the chick could be placed back in the box later this week. With only a few days from underneath mom Peregrine’s watchful eye, she would continue to care for the chick as if nothing happened.

#2, if the chick has to be separated from its parents more than a week because of a more extensive injury, we could not put it back in its box. Such a long separation means the parents would lose the drive to care for chicks. However, WBS would foster the chick to an area nest with similar aged chicks or send the chick to another area that has chicks of a similar age. We have a great network of fellow Midwest Peregrine banders, so finding a nest would pose little problem, and fostering has been very successful with many species of raptors (including Peregrines).

#3, if the chick has an injury that would make its wild survival impossible, WBS would gladly accept and train the bird for use in our education programs. Many of our education ambassadors have injuries that make them permanent captives, and with the right training and care, this Peregrine would help especially children learn about the species.

Our number 1 goal is to get the bird back into the wild, and we will do our best to achieve this. Rest assured I will keep you all informed of our miracle chick.

May 11, 2018

Hello everyone! Wow, do our chicks grow fast. Today is 11 May, making the kids 18 days old. When they were hatched they were each about an ounce and a half. At 18 days of age males will be about 12 ounces and females about 16 ounces, or one pound. That’s an 1,100% increase in weight for females and an 800% increase for males. Their high protein diet of other birds helps them grow up quick. Raptor chicks are altricial, which means they are hatched helpless and need a lot of parental care to become juveniles that may successfully leave the nest and start their own lives. This is compared to precocial, like wild turkey chicks, that can walk and even fly short flights just hours after hatching. All chicks grow quickly, since youngsters in nature are more vulnerable to predators. Peregrine chicks getting big and leaving the nest quickly means less predators can catch and eat them.

There were few questions over the last week, and some of the ones I had I’d already answered in the last Ask Jeff. However, I am happy to write again about the 2 unhatched eggs. We’ll probably never know why they didn’t hatch. Some reasons could be, a) small cracks in the eggs that allowed bacteria to enter, b) mom and dad are quite old for wild Peregrines (12 and 14 years old respectively) meaning their internal organs might not be working as well as when they were younger, or c) the eggs could have gotten cooled for too long a time span and died from this. With the hard freezes and cold days we had in mid April, I would vote for c. If mom had to leave the eggs to help the male chase away a potential territory rival or aerial predator, the eggs could have gotten chilled for too long.

I just looked on the web cam and couldn’t see the 2 unhatched eggs. As the chicks got bigger and moved around the nest they could have broken the eggs, or pressure could have built up because of extreme bacterial action and the eggs popped. If the eggs are there when I collect the chicks for banding, I’ll remove them from the nest.

Speaking of banding, I’ll go to the nest on Monday morning, 14 May and remove the chicks for about an hour for banding and drawing a small amount of their blood for analysis. The blood will be tested for toxins that could have entered the eggs as they were developing in the mother. Peregrines became endangered because of the pesticide DDT, which entered the parents because the DDT was within their prey. If someone had been looking at Peregrine chick blood in the 1950’s, maybe we could have stopped using DDT soon enough to keep Peregrines from becoming endangered (they became endangered in 1972 and were taken off the federal endangered list in 1998). This is the thinking behind current blood analysis. If we find a trend in a toxin showing up in their blood, we can hopefully do something about it to keep the species from again becoming endangered.

When banding I’ll also find out what sex each chick is. I’ll let you all know early next week. Until then, keep watching!

May 2, 2018

Hello All! First, I want to say thank you very much for all your emails trying to help with viewing the bands on each of the parents. In the end the person that controls the camera and I figured out that we have the same male as last year, and the same female as the last 3 years. The male was hacked, or released, as a young falcon at a power plant in north central Missouri in 2004. The female was banded as a chick at a cliff nest in 2006 at a state park in Minnesota. For reasons we will never figure out, the parents never presented their color banded legs to the camera until each started feeding the chicks. Then it became easy to get their ID’s.

This year we have only 2 chicks from the 4 eggs that were laid. There could be many reasons the other 2 eggs didn’t hatch, including small cracks that let bacteria into the eggs, eggs got cooled for too long a time period and died, the eggs didn’t get fertilized correctly when they were still in the female, etc. Also, our female is 12 years old now and the male 14. In the wild Peregrine world each has reached the upper limits of their lives. Maybe internal organs aren’t working as efficiently as they once did.

The 2 chicks hatched on 23 April, which means I will be banding them on 14 May. They’ll be 21 days old on banding day. Once the chicks reach 17-18 days old their legs and feet are full sized. This means I can safely place the correct sized bands on their legs, of course after measuring their legs. Males are a third smaller than females. They get a size 6 band, and the females get a size 7A band.

Now to the great questions I received over the last week.

Several asked when the chicks fledge. On the average the males fledge at about 45 days old and the females about 55 days old. If my math is correct, the chicks should be fledging in mid June. They are still too young to tell what sex each is, and until I actually have my hands on them it’ll be just speculation on their sexes.

Another asked how the male gets the prey to the female so she can feed the babies. In case you don’t know, the female does the majority of feeding the babies, especially during the first 20-25 days of their lives. As mentioned earlier, mom is the larger of the 2 sexes, and one of the reasons we think she’s larger is to better defend the nest from other aerial or ground predators. So, dad catches, kills and plucks most of the prey during these early days. Then he’ll fly by the nest. Mom sees he has prey, then she’ll fly out and in mid air the male will transfer the prey to mom. Peregrines are one of the most maneuverable of all birds of prey, so it would be quite spectacular to be able to see the transfers happen. Maybe one day there will be Peregrine cameras that swivel and focus fast enough to follow the female as she receives the prey for her chicks.

Finally someone asked if the bright lights of the Portage de Sioux Energy Center are any kind of detriment to the Peregrines. My short answer would be no. If anything, the lights may allow the Peregrines to hunt further into the night. There are hundreds of bird species that migrate at night, so if these birds are passing through the lights they could become prey for our falcons. Many years ago I read a very interesting account of Peregrines living in the Chicago area preying on bats after dark. There was enough light given off by all the buildings in that huge city where the Peregrines could see bats well enough to catch them. We have 2 other energy centers in the greater St. Louis area that have nesting Peregrines, and I know there are many other power plants in the nation that have nesting Peregrines. With all this Peregrine action, it seems to me the lights don’t disturb the Peregrines at all. Plants that produce energy for we humans are located near large bodies of water. Water is needed for many reactions and cooling processes, hence their locations. Most of these plants have high buildings or stacks, which are ideal places for Peregrines to hunt from (before humans Peregrines nested and still do nest on cliffs above rivers and oceans). Especially the Mississippi River, with it mostly north to south flow, has many bird species that use it and its flood plain as a migration corridor. Peregrines feed almost exclusively on birds, so plants and even other tall buildings near water are ideal places for Peregrines to live.