Tag Archives: wing feathers

A surprise visit to see the Ks

I was not expecting to see a notification that Ferris Akel was on the Cornell University Campus in Ithaca this evening. What a wonderful surprise! The reason that everyone wants to see Big Red and her family is not to see spectacular things but, really, it is just to know that each and every one of them is safe and well. After the worry of Hurricane Elsa and the nests along the southwest coast of Florida, this was simply a joyful treat.

Ferris found K1 on a window ledge. How she got there is anyone’s guess. My goodness she is so cute. Whoever said that she is a mini-Big Red is so right. Her plumage is such a deep brick red and she has a full red-feathered belly band, too, with lots of peach on her chest.

Look at the image below. Notice the feathered area that extends above K1’s eyelid. It starts at the beak and goes to the back of the head. It is called the supercilium. The supercilium helps keep the glare out of K1’s eyes! It is often simply called a bird’s eyebrow.

Hawks can turn their heads 270 degrees. Sometimes it looks like they can do the complete 360 but they can’t.

You can see in the image below, despite it being blurry (rain at started), the peach on the chest and the low very dark feathers of the belly band.

The cere is the area around the nostrils above the beak. You can easily see it in the image of K1 above and below. It is light yellow. Notice that the eyes are a green-gray. When K1 is an adult they will be brown getting a deeper brown the older she gets.

Last year, Big Red and Arthur’s fledgling, J3, was born with deep brown eyes.

Ferris did some close ups of K1’s back so that we could see the scapular ‘V’. When both wings are held tight to the body it is the ‘V’ on the upper back. Examine K1’s scapular V. It has its own pattern. Some people use this along with the tail and the belly band to try and identify hawks that are not banded.

You can think of the scapular V as being the way the hawk’s back looks when the wings are closed.

K1 has a white terminal band on her tail feathers. In fact, it is rather wide. Notice the dark bands. When hawks fledge, we want them to have five, preferably six dark bands, so that they get lift and control and will be successful. K1 now has at least eight dark bands. We know that she is also an excellent flier.

The tail feathers help the hawk to do controlled manoeuvres. This is why it is so much better if they are longer at the time of fledge. The wing feathers – you can see the tips of them in the image below- are the most useful for flying. Did you know that the wing and tail feathers of the fledglings are actually longer than those of the adults? This is to assist them when they are learning to fly. After their first moult, they will grow in the standard length of an adult hawk (return to a normal length). Another interesting fact is that at the time of fledging, the feathers actually weigh more than the bird itself!

At the beginning of their second year, when they moult, the fledglings will get their red tails. When Big Red and Arthur bonded, Arthur did not yet have his red tail! Lots of people questioned Big Red’s intentions. She had many suitors but I think we can all agree that Big Red knew best. She has a wonderful mate in Arthur.

Ferris found K3 in one of the pine trees near to Rice Hall’s parking lot. What gave K3 away? Robins vocalizing!

K3 is looking at something intently.

K3 was doing a lot of preening. The preen or the oil glands are at the base of the tail. These oils reinforce or condition the surface of the feathers. Just like the oil you put in your car, the preen oil changes composition during the year. This oil, once it is exposed to sunlight, has been found to contain vitamin D.

Big Red was over on the ledge at Bradfield. I almost did not recognize her. In the summer when Big Red begins to moult, she starts becoming Big Blond. It looks to me like this process is starting.

But why do hawks moult? Feathers are made out of keratin, just like human fingernails. But unlike our fingernails, feathers do not continually grow. Once they are fully formed, they stop growing. Over time the feathers get damaged. This damage comes from normal wear and tear, the sunlight, parasites, and from injuries. These feathers have to be renewed. Hawks do not moult or change their feathers all at once. They would be unable to fly or function and would die. Moult is a gradual process. Big Red does not begin her moult during breeding season. It is too hard on her. The birds deplete their calcium producing eggs and Red tail hawks can lose approximately 20-30% of their body weight by the time the chicks fledge. Big Red will spend the summer and fall getting back into condition and replacing her feathers.

Feathers help the birds fly, they offer camouflage, and they also keep the birds dry.

Arthur was on ‘the throne’ on Bradfield. Neither Big Red nor Arthur moved from their locations during Ferris’s visit. Both Ks appeared to have a crop and neither were food begging. The crop is the first stage of digestion. It is like a pouch under the beak and the mouth. The crop expands with the food. The undigestables are rolled around in the crop to form a casting which the hawk throws up or ‘casts’. The rest of the food that can be digested enters the digestive system proper. The only raptor that does not have a crop is the owl. Owls have gizzards. If you watch Ospreys you will have looked to see if the chicks have crops. That way you can tell if they have had food recently.

It was an absolutely wonderful surprise. There is nothing nicer than spending the end of the day with Big Red and her family. I hope you enjoyed seeing them, too.

This is a great shout out to Ferris Akel. Thank you Ferris for taking your time to go and check on ‘the family’. It is wonderful to know that they are all fine and well.

Feathers and Preening

You have probably never thought much about feathers unless you raise chickens and wind up plucking them yourself. Or your duvet is full of down and feathers and you find them all over the place if there is a small hole. But, maybe, like many of us, you wish you had wings and could fly – like Icarus – but not with the same consequences. I wish I had feathers and wings because then I would soar into the sky as high as I could go!

Before I begin, this posting is not the definitive answer to everything about feathers or preening. But I hope to give you a glimpse into the importance of both to Red-tail hawks. Sort of a nutshell version. If you are really interested in feathers and believe me, there is a lot to learn, I have included the name of a good book later in this blog.

Red-tail hawk chicks begin to jump and flap in the nest, according to my observations, approximately 2-3 weeks after they hatch. They are building the muscles in their wings when they flap and flap. Flight feathers not only help birds fly and soar but they are contoured and offer protection from the weather. In the first photo below, there is a snow and ice storm in Ithaca on May 8. Big Red’s feathers are keeping her dry and also protecting the chicks. Look carefully at the one under her beautiful red tail feathers.

Feathers keep birds warm and dry – in ice, rain, and snow. The chicks have not yet developed feathers to do this so Big Red covers them.

Several times this spring, the rain has just been torrential in Ithaca. Again, the feathers kept Big Red, no matter how drenched she looked, dry and in turn, she spreads her wings to keep the chicks dry and warm.

For us newbies, we were worried about Big Red in all the rainy weather. Here she is covering the chicks. They get so warm that they often stick their heads out just to get cool. And just a note. Both Big Red and Arthur have brood patches where their feathers have worn down from incubating the eggs and then protecting the chicks.

When it is really hot and humid as it is in both Ithaca and Syracuse the last few days, rain can be very welcome to hot hawks. Below is an image from the Syracuse University Hawk cam showing two of their newly fledged red-tails dancing in the rain to cool off. It reminds me of being in India in the late 1980s and 1990s. You would beg for the rains to come to cool off and would run out into the rain ever so thankful!

So remember. Flight feathers are not just for flying but they are also for protection from the weather. The water resistance from the feathers comes from hydrostatic pressure. Hydrostatic pressure is the tension between the structure of the feather versus the pressure of the water. Water droplets bead on the feathers.

Arthur leaving to get prey for the chicks with Big Red giving him directions. Notice his legs tucked up and the slight curve of his wings at the end and, of course, that beautiful red tail.

Wing feathers are the longest and the most useful for flying. Below is a closeup of one of the chicks with their wing feathers starting to grow. Also notice the tail feathers that are beginning on the chick and the recognizable “red tail” of the Red Tail Hawk on Big Red. The chicks will not get their beautiful red tails until they are in their second year. Tail feathers are like the rudder on a boat. They help the birds manoeuvre. About a month after they have fledged, the chicks should be able to soar into the sky.

Approximately 18% of the weight of a Red-tail Hawk comes from feathers. By the time the chicks are 29-31 days old, their dorsal wings should be 90% feathered. Their legs will begin to feather and they will get the characteristic “pantaloons”. The ear openings should be covered and the upper tail coverts should be well developed. By the time they are 35 days old (about a week from a possible fledging or first flight off the nest), the head will be at least 50% feathered, the dorsal body will be 95% feathered, and the breast should be 90% feathered. Their tail feathers should be five to six bands long, preferably. The more bands the more successful the first flight will be.

This chick is J3, the youngest. He is 31 days old. Note the distinctive “peach” on the breast, the lovely dark feathers marking the “apron” below the crop. The downy head is beginning to gets its feathers and the feathers covering the legs are there.

At the time these chicks fledge, their wing and tail feathers will be longer than their parents. With their first molt, they will return to normal. Molting is the falling out and gradual replacement of the feathers.

There is a really good book on feathers. It is Feathers: the evolution of a modern miracle by Thor Hansen. There is so much to learn including every part and its function! Apparently humans have the DNA to grow feathers but we don’t have the “switch” to turn it on and off. Feathers are much more efficient than their hair. Hawks also use their feathers like a sharpening tool to keep their beaks in perfect condition.

The simple definition of preening is that it is cleaning and maintaining the feathers. Preening reinforces and conditions the surface of the feathers with gland oils. These gland oils contain vitamin D. When the feathers are exposed to sunlight after preening, the oil works as a protective conditioner. The oil in the glands change composition during the year just like you will, if you live in a cold climate in the winter, change the weight of your oil in your car. Red-tail hawks spend approximately 77% of their time preening.

This is an example of a warble. This is when the head of the bird is folded all the way back and down and they are preening their wings
The chicks learn quickly how to balance themselves on branches or metal railings and preen at the same time!

One of the things that I found most interesting about the feathers is that because they are hollow, some researchers understand that birds can feel the changes in barometric pressure and will know what weather conditions are approaching. They are more likely to know the precise weather approaching than the local weather station. They have to. They live outside in the trees, roost on the ledges of buildings, and depend on millions of years of evolution to give them clues to nature’s mysteries so they can survive.