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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, including 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, especially 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
From Jeff:
Hello, everyone and welcome back to Ask Jeff and the Peregrine Web Cam! I am thrilled to again be able to answer your questions. Let's get started.

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 hatching.

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.

Watch the video of Coal sitting on the eggs! Notice, he flies in and waits for SiouxZee to leave. Then he takes her place to help incubate the eggs. View video.

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. t 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.

Photo courtesy of Randy Koratev.

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