The two little ones on the Minnesota Department of Natural Resources nest are quite a lively pair. First time, four year old Harry has learned to feed and Nancy has relaxed. Harry is good on the nest and food is there. The little ones are rather spunky to say the least!
Bonnie went out hunting and brought a small live garter snake back to the nest. Lily got there first and ate the entire snake – live – all by herself – as Tiger and Bonnie looked on in amazement.
Look closely at how thick Tiger’s legs are. Look down at its talons. These two owlets are really growing! Both of them are flapping their wings and wandering around the nest. Tiger is very sturdy on those sturdy limbs! Both of them are endless pits in terms of wanting food.
Li’l and Big at the Duke Farm nest are growing and growing. There have been tandem feedings and attempts at self-feeding! Doing good. Li’l can hold its own against its big sib.
It really does help to be the only eaglet in the nest with a parental territory that is full of prey. Kisatchie is always being fed and cared for by its mom, Anna. Louis continues to be an expert fisherman and Kisatchie always has a full crop. I don’t believe this eaglet would understand what hunger actually was. And you know what? That is just fine. His feathers will go strong. Eaglets that have had periods – several of hunger – have thinner spots in their feathers.
In constrast, the Redding triplets are always hungry it seems. Two of them are trying to climb out of the nest cup so that they can have some of that juicy fish. It keeps mom and dad very busy!
I will leave you with an image of my heroine, Big Red, the Red Tail Hawk incubating three eggs on a light stand on the Cornell Campus. Big Red always gets my vote for ‘Mom of the Year’. She is quite amazing! Year after year she gets soaked, gets encrusted in snow and ice, and still she raises the strongest happiest eyasses. She is much loved.
This was a short update on how some of the nests are doing. Thank you for joining me today. Stay safe everyone!
Thank you to the following streaming cams where I got my screen images: Cornell Bird Lab, the Kisatchie National Forest, , the Pittsburgh Hays Eagle Cam, Friends of Redding Eagles, Farmer Derek, MN DNR Eagle Cam, and Duke Farms.
UPDATE ON THE ACHIEVA OSPREY NEST IN ST PETERSBURG. Tiny Tot was fed this morning at 9:27 after the other two. He had a small crop. It was the first time he ate in 3 full days. Tiny Tot later later had some seizures. It is unclear what damage the lack of food did to his internal organs. A huge catfish came in at 4:22. The two bigger ones ate for a couple of hours. Tiny attempted to get food and was pecked by 2. The dad, Jack, came and took the extra fish away. It is quite sad to see anything suffer so much, begging for food – literally starving to death. It is nothing short of a slow horrible death. The question is why? Is there a lack of fish? Does the father have two families? Other Osprey nests raise three healthy osplets to fledge – even small ones. A good example is Loch Arkaig in 2020.
The Achieva Credit Union’s Osprey Nest in St Petersburg, Florida has caused a lot of people to become anxious and loose sleep. It hasn’t just been me. Tiny Tot (or Tumbles) has a fan club that wants this clever little bird to succeed. It is now 7:30pm Saturday 27 March nest time. Jack has made four fish deliveries today – FOUR! The last days have had the little one, number 3, Tiny Tot or Tumbles – whatever you want to call him – begging for food and trying out ingenious ways to try and get it. Sometimes he was too late and the fish was gone but, today Tiny Tot prevailed.
The deliveries were made at 7:30, 9:48, 1:15, and 5:33. During the second delivery, Tiny Tot got under Diane, the female, just enough that he was out of range of any bonking. #2 tried to batter the little one but it stopped short – because it would have hit its mom! Brilliant move. #2 zero – Tiny Tot 1. It also put Tiny Tot in a good position for getting some nice bites. Progress continued.
In the image below, Tiny Tot is in front of Diane. He has what we call a Cropzilla – a nice pillow. The eldest is the one nearest us and it is passed out in a food coma. Tiny Tot had passed out on the tail of #2 but he is looking like he wouldn’t mind a little top up! Too funny. Mom had a nice meal, too.
Jack was a great provider today. 27 March 2021
Over at the SW Florida Eagle Nest on the Pritchett Farm, E18 branched today. E18 is one of two eaglets of Harriet and M15. Ironically, E18 was bonked so aggressively by E17 that many worried including the wildlife technicians when they both had to go into care for having Conjunctivitis. But something magical happened. The two are twins, born within a couple of hours of one another. The other day an intruder came and E18 instinctively put those huge wings you can see in the image below over E17 to protect her. Branching is one of an eaglet’s milestones and these two are doing brilliant! E17 branched yesterday but today, E18 had to go just a little higher. Remember that old rhyme: ‘Anything you can do, I can do better!’ It is all in fun but these two do move one another along in the challenges they have to get to be juveniles.
E18 branches. Look at those gorgeous wings. 27 March 2021
And good things continue to happen over at the nest of Big Red and Arthur in Ithaca, New York. Big Red laid the first egg of the 2021 season yesterday. If it hatches first, it will be K1. Last year it was the second egg that hatched first. So one never knows! Tomorrow we should be expecting the second egg to arrive. But, over the past three seasons, Big Red has often been reluctant to give her mate, Arthur, much incubation or feeding time. Well, that seems to be changing. So far, I have counted five times that Big Red has had Arthur taking over the nest. The times were 6:36-8:56, 10:56-11:13, 13:20-13:46, 14:08-15:20, and 17:38-18:33. Arthur does a fantastic job. He always checks and rolls the egg and shimmies up. So cute! Maybe this year she will let him do a little more of the feeding! Tomorrow is egg watch.
Arthur incubating their egg. 27 March 2021
Even the hand offs of duty have gotten all worked out.
Arthur out, Big Red in. 27 March 2021.
That is it for this Saturday and Bird World. It is all good! Thanks so much for joining me. I am so glad that you are enjoying these incredible birds ‘er dinosaurs. See you soon.
Thank you to Cornell Labs Bird RTH Streaming Cam, Achieva Osprey Streaming Cam, and D Pritchett and the SWFL Eagle Streaming Cam. Those cams are where I capture my images.
There have certainly been a number of nest hijacks this season as well as a number of unwelcome intruders. The threats by the Great Horned Owls continue across the United States on well established Bald Eagle nests. Ravens have been attacking the Bald Eagle at the Channel Islands nest and, of course, we are more than aware of the danger the GHOW in Fort Myers is posing to the nest of M15 and Harriet. At the Pittsburg Hays Bald Eagle nest, on the night of 23-24 February, a GHOW launched an attack on the nest. It was the first ever recorded in that nest’s history. Daisy the Duck was not a threat to the White-Bellied Sea Eagles when she borrowed their nest to lay her eggs but the GHOW sure was to the Bald Eagles near Newton, Kansas who backed off and surrendered the nest to the GHOW. It is, of course, not just the ‘top of the food chain’ raptors that are being bothered, injured, or killed, it is also the smaller raptors such as the Red-Tailed Hawks.
For the past few days, Big Red and Arthur, the resident Red-tail Hawks who ‘own’ the territory within the Cornell Campus at Ithaca, have been renovating their nest on the light stand at the Cornell stadium. The pair have been together since the death of Big Red’s long term mate, Ezra, in 2017. Ezra was killed defending Big Red. It was shortly after Ezra’s death in March, that a very young Red Tail Hawk arrived on the nest. He didn’t even have his red tail! By the fall, when Arthur had shed his juvenile plumage, Big Red had decided that he was the one. She had put several potential mates through what could only be called an exercise to see if they were worthy of her and her territory and also to see if they would be good defenders and providers for her and the eyases. Arthur won the contest. The pair successfully raised eyases in 2018 (when Arthur was two), 2019, and in 2020, the Js. This year will be the Ks.
It is now less than a month til the first egg will be laid and the two are working hard to get what is left of the nest after the fledging of the Js. They began when there was still snow on the nest a few days ago.
‘Look at the mess those kids made when they kept trying to fledge from between the light boxes! Arthurrrrrrrr. There is a lot of work to do. You had better get busy.’
These two hawks are the funniest birds I have ever seen. Big Red is VERY loud and gives Arthur distinct instructions about everything. It is quite clear who wears the pantaloons in this nest. Year after year, they have sent observers into hysterical states of laughter, this eighteen year old RTH and her five year old mate.
The pair made several visits calculating the amount of nesting material that they are going to need to get the platform readied. Arthur brings in massive amounts of twigs building up the front and the sides of the nest over the following days as the snow melts.
And then, on the morning of 25 February at 6:56 a group of European Starlings come to check out the nest! Are they thinking that this might be a really good place for them to raise their young? Oh, I don’t think so.
Twenty-three minutes later, Arthur arrives at the nest with a piece of greenery. While raptors will use evergreen to keep away insects, laying a piece of pine in the nest bowl is a signal to all other birds that this nest is occupied.
After placing the pine needles in the nest bowl, Arthur looks around. ‘Where are they!? I hope they are watching!’.
Arthur decides to work on the nest bowl rubbing his chest against the twigs and nesting material to make an indent for Big Red’s eggs.
And before he leaves he takes a very good look around. Arthur knows that Big Red might like a nice squirrel for dinner but she would also love to eat any European Starling that tries to mess with HER nest.
I want to leave you with a smile on your face. It’s the end of February and we can all use one.
Big Red and Arthur do many things to teach their eyases. Sometimes it is about nest building and at other times it is imprinting the different prey items in their mind so they know what they should and should not eat in the future. And, sometimes, Arthur plays tricks. Have a laugh. The video is three minutes long:
Aren’t those little eyases just the cutest?!
Thanks for checking in with me and the birds. Updates tomorrow on the progress of the new mom at the KNF nest and some recent happenings in the Bald Eagle nest – first eggs happening everywhere including Canada. It is going to be busy in a month!
Thank you to the Cornell Ornithology Lab for its streaming cam on the nest of Big Red and Arthur.
First, before you get anxious, Daisy the Duck managed through the high temperature of Sydney yesterday. She left the nest at 15:11:10 to forage and returned twenty minutes before sun down at 19:45. It is currently day 14 of her brooding and it is 5:43 Monday the 25th of January in Sydney. All is well in the nest. The sea eagles did not make an appearance in the evening and Daisy did not go out foraging before dawn this morning. It is due to be another hot day on the nest.
Daisy just before dawn, 25 January 2021.
I have said often that the lives of our feathered friends hang on a thread. Anything can happen at any time. Sadly, much of the time the root cause has something to do with humans and our lack of respect for the environment. Rat poison – rodenticide – contains chemicals that cause the mice and rats to bleed internally. But before they did their movements slow down. Raptors (falcons, hawks, eagles) often catch the dying animals. While it is not always lethal for the larger birds such as adult Bald Eagles, it is for the smaller hawks and falcons and their babies. Toxins in the water flushed out from industrial plants is another or the heating of the oceans causes toxic red algae. Window strike breaks their necks. Tossing any food waste onto the highways causes the birds to come and not watching, they get hit by vehicles. The mesh bags that hold oranges and other fruits along with not cutting the ties on face masks tangles up the birds as does the mesh that people and farms use to cover the trees and bushes in their orchards. And of course the glue strips that catch the birds and cause them such devastating pain trying to free their little legs. I could go on. The list would be endless. The most prominent way is through the loss of habitat.
In a short period of time, in the world of our beautiful birds, there has been intense pain and great happiness.
At Captiva Island, there was such joy when Peace and Hope were each born, within six hours of one another, on 14 December 2020.
Hope and Peace being fed fish on Christmas Day by their dad, Joe.
Fishing line was discovered in the nest with a hook on it. The American Eagle Federation got permission from the US Wildlife Service to have it removed. On or about the same day, the parents brought a rat into the nest to feed the eaglets. No one knows precisely what happened but it was observed that Peace no longer wanted to eat and was becoming dehydrated. Peace passed away. Hope continued to thrive until a couple of days ago when people started noticing that ‘something was wrong’. They didn’t know what. Many noticed tremors in her leg. Others watched as it appeared she could not cough up a pellet. (Raptors cannot process all of the food that they eat. What they can’t is formed into a pellet that is coughed up). Some saw blood on her wing and leg. She coughed and choked all day, January 23. Many think her heart gave out last night. Connie, her mother, flew to the nest as she was taking her last breaths. One of the saddest things is that prior to Hope and Peace, Joe and Connie had fledged nineteen juvenile Bald Eagles in the twelve years they have been together. In fact, people exclaimed how physically strong these two were. Hope crawled out of the nest and up to the end where the parents bring in food when she was only two days old. They were both growing and getting strong. Peace died on 13 January. A few days, Joe took her body from the nest. Many are hoping that a necroscopy can be done on Hope to determine the cause of her death.
January 20, 2021. Hope with Connie on the nest overlooking their territory.
In the image above, three days ago, you can see how Hope was getting her beautiful dark brown juvenile feathers.
Apologies. Hope is moving. 23 January 2021.
In the morning fog, the same day of her death, Hope stands talls and is jumping up and down on the nest flapping her wings.
Today, Connie is standing over the body of her daughter, Hope, shading it. From all available evidence, birds grieve just like humans when they lose a child.
Connie with the body of Hope.
There is frustration and anger and the debates continue as to whether or not intervention in the lives of these majestic birds should take place. Some argue that we are fortunate to be able to view their lives but that we should not intervene to help them unless it is clearly something a human has caused. Others state the opposite. While we are now privileged to watch the comings and goings of the birds, it is our duty to protect them so that they thrive. Unfortunately, nothing will bring back to the vibrant eaglets, Peace and Hope.
January 23 was also the day that Harriet and M15’s two eaglets hatched at Fort Myers, Florida.
E17 and E18 hatched just an hour and a half apart. What were two wet limp bodies have turned into fuzzy little bonking babies this morning!
E17 and E 18
Notice the white at the top end of their beak. That is the ‘egg tooth’. The egg tooth is a small white protuberance that helps the birds chip away at the shell so that they can hatch. By hitting on the shell, the egg tooth makes the first pip! The egg tooth disappears in a few weeks.
Bonking of bobbing into one another after hatch is a rather normal experience. The little birds cannot focus their eyes well, their heads are bigger and awkward til they get some strength in their necks, and because they know that food comes from their beak and the parent’s, you will often see them bonking back and forth. This should end after a few days but in some nests it persists as a means of establishing dominance. In some cases it can lead to siblicide, the killing of the other sibling.
And on 23 January in New Zealand, the Royal Cam Albatross chick belonging to LGL, Lime Green Lime, and LGK, Lime Green Black, hatched. New Zealand gives the albatross born at Tairoa coloured bands for identification. This couple were chosen to be the stars of the camera this year. The baby Albatross will receive a Maori name right before it fledges and we should know in a couple of weeks if it is a male or a female.
DOC Ranger Julia and LGK as he sees his baby for the first time.
I can always be found praising the New Zealand Department of Conservation. They protect their birds. Once the rangers noticed the ‘pip’ of the Royal Albatross egg of LGK and LGL, it was removed and a dummy egg was placed under the parent to continue incubating. The ‘real egg’ was placed in an incubator. The reason for this is fly strike, the infestation of fly larvae during the period that the chick is trying to hatch. This can lead to their death. Royal Albatross are a highly endangered species because of climate change and long haul fishing. The New Zealand government is taking a very proactive role in trying to keep their birds healthy and also in promoting the use of varies methods to protect bycatch, whether it is our gentle albatrosses or sea turtles.
This is a great video to introduce you to the topic of bycatch and how important it is to get international agreements in place to protect the ocean’s animals.
There is much you can do to help birds from cutting the lines to your masks and putting them in the trash, to educating people on feeding birds at feeders and ponds, to lobbying international agencies demanding the end to bycatch. If you go back through my posts you will find several dedicated to ways that you can help birds no matter what your financial status.
Daisy on her nest just after dawn breaks, 24 January 2021.
I will have a full report on Daisy’s day in about nine hours. The weather will be hot again in the Sydney Olympic Park and we hope that means that no sea eagles will come to see if they can catch Daisy!
Thank you for joining in the daily life of our favourite little Black Pacific Duck, Daisy.
And thank you to Pritchett for the camera views of Harriet and M15, Captiva Eagle Cam and the AEF for the camera views of Joe and Connie, to Cornell Bird Cams and the NZ Department of Conservation for their camera views of LGL and LGK, and to Sea Eagle Cam, Birdlife Australia, and the Discovery Centre for the camera views of Daisy.
For the past week I have been posting information on how we can all join in and make our environment friendlier to birds. The tips and the ongoing discussion with my chatters on the Cornell RTH FB page have been enriching. Those posts were a way of remembering J1, the eldest chick of Big Red and Arthur, who died a week ago today after what is believed to be a window strike at Weill Hall. J1 was a super large very maternal bird who could be hawk-fierce when required or a gentle goof pulling the tail feathers of her brothers if they sat on a bar above her. She loved playing soccer with pinecones and taking baths in the puddles after a hot day in Ithaca. Her birth brought joy to all and as she grew most recognized that she would be a gentle but firm mother like Big Red. Because of COVID-19 and the escalating deaths and subsequent civil unrest, her death sparked a deep sense of loss not only within her hawk family but also with the BOGs in Ithaca and those who love this family around the world. Big Red and Arthur led the two remaining chicks away from Tower Road and the business of the campus near Bradfield and Weill out to Holey Cow. Just looking it appears that the distance is around a mile but I could be all wrong. The area is rural farmyard territory as opposed to urban with its buildings, streets, and cars. And the parents have kept them near the barns with the cows and sheep and the fields where Big Red’s mate, Ezra, used to hunt. One evening all four took part in a team hunting event. Big Red from one side of the pine tree and Arthur on the other would fly into the tree chasing a squirrel down for the two juveniles to hunt it. The move has caused the chicks to slow way down and stop random flying stunts between buildings. You say, “Did Big Red and Arthur know that J1 had died?” My answer to you is “Of course, they knew.” Would they have wished that Cornell University would have earlier installed window reflective glass on their buildings? Absolutely. And so, that is why I am writing to you tonight. To introduce you to ways that you can help birds in your own neighborhood.
Most of you will know some of these points but you might have forgotten or maybe you didn’t know. I certainly didn’t know all of them and tonight I find that I am still learning. So here goes:
Make all of your windows bird friendly by installing strips on the outside so there is no bird strike. Check your local wildlife or nature centre. They often have this available in their shop.
Speaking of windows. Governments in Australia have announced that all buildings will now be required to use reflective glass. It is estimated that 1 million birds die from window strikes annually. Supporters of the new reflective glass windows believe that they can save 90% of the birds with this new measure. Write to anyone in your community who will listen!
Bird-friendly coffee. Almost everyone reading this blog will drink some kind of coffee a day. But, as I have learned recently, not all coffee is the same. There are now many organic beans and blends as well as fair trade coffees but if you want to be the most environmentally friendly with your cup of java, then you must find bird friendly coffee. And this is not easy! The Smithsonian must certify the coffee to be grown under shade so that the forests are not cleared to qualify beyond being organic and fair trade. So look for the labelling and ask your local roaster to get beans brought in for you or you can order on line.
Water. The summers are getting warmer. The heat impacts all of us. One simple way to help the birds is to put out bowls of water so that they have a fresh drink and a place to have a bath and cool off. You don’t need to go down and buy a fancy bird bath. Readers of my postings have suggested checking your local thrift store for bowls or even bird baths. Many use the dishes that go under pots. One even suggested the plastic liners for paint trays (new, of course). Since I work with clay, we have an array of shallow bowls outside and every day around 4pm the little song birds line up for a drink and a splash. One day the largest of our local Grackle community decided to have a bath. It was sweet.
Cats. Cats are one of the most prominent dangers to birds. Where I live it is illegal to let your cats outside. But in many parts of the world this is not the case.
Herbicides and pesticides. One major birdseed company in the US (who also supplied herbicides and pesticides for gardens and lawns) was discovered to have poison seed in their product several years ago. Make sure you know where your birdseed comes from BUT also let your garden be natural. All of the treatments for lawns are very dangerous to animals.
Mouse and rat poison. Rodenticide. Do not use poisons to trap mice and rats. They mice and rats eat the poison, get sluggish, and are easy for the raptors to catch. Then they die. It has been clearly proven that raptors are much better at keeping down the rat population than poisons. Tell anyone you know not to use these products that stop the blood from coagulating. In fact, cats can also die if they eat a poisoned mouse or rat.
Plant a tree. During this very chaotic spring, people have been seeking calm. Trees and gardens offer places for peaceful contemplation. They also help the biosphere. So instead of paving your patio, consider creating a rustic treed space that is bird friendly instead.
Slow down. When you drive slow down. It will cause less deaths from window strike.
You might want to keep gear in your vehicle to help with injured birds. This can include but is not limited to gloves, a secure cage, and soft blanket. Know the contact numbers for your local wildlife rehabilitation centre.
These are not the only ways but they are a beginning. You might want to think about ordering the bookthat was recommended to me today. It is Nature’s Best Hope: A New Approach to Conservation that Starts in Your Yard.
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 wingsThe 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.
It is called Reverse Sex-size diamorphism. There are several theories as to why this happens with Red-Tail Hawks.
The first is that the females had to be larger to protect themselves from the feisty males.
The second is that the females selected smaller males to be their mates because the size difference allows each of them to hunt different prey and reduce any competition for food between the pair. Raptors that hunt birds are generally smaller and faster with the female specializing on larger prey. At the beginning of the nesting season, the female becomes an active hunter and again when the nestlings are larger. Generally the adults tend to partition the prey resources in their territory.
Another theory is that the females need to be larger because they must accumulate reserves in order to produce eggs. When they are incubating eggs and brooding young, they rely on the male to feed the family. Red-tail hawks are usually born in April when the prey are sluggish and just coming out of hibernation. Small males can make quick turns. In the case of the Red-tails on the Cornell Campus, Arthur W, the male, is known as the ‘stealth bullet.’ He is quick, fast, focused, and quiet when he hunts. Big Red’s former mate, Ezra, was like Arthur W a great hunter but he was also about 30% smaller than Big Red as is Arthur.
Ezra has his wings spread and his legs tucked tight. If you look closely you will see that he is delivering two items to Big Red. The first is a snake and the second is a flower! It is very difficult to get Big Red and Arthur to stand up straight at the same time. They certainly do not listen to requests from humans!This is the closest I have come to finding an image that might be able to show you the difference in their size. Big Red is on the left and has her head leaning back preening and she is a little more slumped than Arthur who is on the right.
In terms of the nestlings, the only way to positively known the gender of the bird is through either a DNA sample or you see them laying an egg when they are older. Everyone likes to guess the sex of the chicks growing in the nest cup. Using reverse sex-size diamorphism, we speculation whois a female by their overall size as they grow in the nest and the size of their feet. But again, no one can be absolutely sure. In the past one of the small nestlings was always believed to be a male. This particular bird injured its wing and, as a result, had to be taken to a vet. The bird’s DNA was tested and, to the surprise of many, it was determined to be a female. So not every small Red-tail Hawk is a male!
In terms of the relative size of each J, J1 is the largest of the three. Early in its development, everyone noticed the large size of its feet. Now as a juvenile, J1 remains the largest of the three siblings. But there is something else about J1 that I personally find fascinating. J1 is very much interested in nest maintenance. She can be seen, even today, mimicking Big Red in attempts to vent the nest bowl. She rearranges the nest twigs and on the second day after she fledged, she brought a branch to the top of the Rice patio. There seems to be 100% agreement that J1 is going to be a good mama like her mother, Big Red.
J3 in the front and J1 behind watching J2 fledge. Look at the difference in the size of their legs as a starting point.
J2 on the other hand is also a large bird, not as large as J1 but larger than J3. J2 was actually the first egg to be laid but the second to hatch and is, therefore, actually the oldest. His fledge was more like a fludge when he climbed up on the light box and then slipped but his flight was still remarkable. J2 has continued to be a very, very strong flyer already interested in hunting. The shape of “his” head – you will notice that I continue to use the term “his” – is also different than that of J1. He has an intense focus and besides bugs and insects he has already been interested in small birds in the territory. To my knowledge he has not caught one. He is also very aggressive. A few of us believe he is truly a male and will be a great hunter like his dad, Arthur W.
J3 eating his first prey drop after fledging.
J3 is the problem child that everyone loves. . J3 was born four days after the other two and it was also the last egg to be laid. Taken together, J3 is actually a week younger than its siblings. That is a lot in the life of a Red-Tail Hawk chick. It may also account for the fact that Arthur W brings food to the nest tower in an apparent effort to feed J3 away from the two larger siblings. Let me try to explain what has been happening. Normally the juveniles are spread out being individuals. This trio is quite different according to the people who have monitored all of the broods on camera (since 2012). It is because they tend to congregate together. To hang out. If one is on the Rice patio, all three might be there.
All three on what is called the Rice patio. Arthur W often makes food drops here but it is also a safe and flat site where they can sleep in the sun or practice their skills.
They might all be on one of the towers including the nest tower. Still, on occasion, they go their separate ways.
J1 in one of the oak trees near the Fernow Building looking at a squirrel.
A prey drop is just that – one of the parents dropping lunch. The juveniles will, unless they have recently eaten, fight for the food with the most aggressive mantling the prey. Unless the prey item is too large for the chick to eat all at once, sharing doesn’t seem to happen. So, because of J3s size and a seemingly lack of aggressiveness in comparison to J2, J3 is somewhat at a disadvantage. This is the reason that I believe Arthur W still supplies food on the nest to the little guy.
Arthur has been dropping lunch off to J3 for several days now. This was around 3pm. He seems to be looking for J3 who arrives almost immediately.J3 mantling the prey that Arthur W dropped on the nest. Remember mantling is a way of protecting the food item so that no one else can steal it.J3 finishing up his afternoon snack.
For now, the gender of the three juveniles is sheer speculation. There are no banding practices and no GPS monitors on the Js. In other words, no identification. It is only when one of the juveniles might find its way to the vet and be both recognized and tested that the sex would be determined.
Tomorrow we are going to talk about the importance of preening.
