The Royal Albatross are one of the largest seabirds in the world. They are also some of the longest lived sea birds in the world with an average life expectancy of forty years. That record was, however broken when ‘Grandma’, the oldest banded bird, raised her last chick at Taiaroa Head, NZ when she was sixty-two years old. This is an excellent video by David Attenborough on Grandma and the only colony of albatross where there are humans at Taiaroa Head near Dundedin, NZ. I hope you can open it!
This year’s yet-to-be-named Royal chick hatched on 24 January 2021. Its parents are Lime-Green-Lime (LGL), the mother. She is twelve years old. Lime-Green-Black is the father and he is eleven years old (LGK).
It is 5 March 2021 in New Zealand. The sun is just rising over Taiaroa Head. Already the cargo vessels are passing where the Albatross breed and raise their chicks.
The Royal Cam chick is forty days old today. This is the first time the chick has spent the night alone on its nest. It is in what is called the ‘pre-guard’ stage. The parents come and feed the chick after foraging and spend some time with them. This transition period to being completely unguarded might just be beginning. Normally the chicks are guarded during their first five or six weeks. After they spend the time alone on their nest except for feeding visits from their parents. The Royal cam chick will fledge when it is about eight months old.
Day in and day out a myriad of different types of shipping vessels pass by Taiaroa Head. This one toots its horn and wakes the Royal Cam chick up as it passes. The sun is just coming up.
The chick will spend the rest of the morning passing the time by watching the sea and playing with the materials in its nest.
Around 1:30 in the afternoon, the chick hears a familiar sound. LGL has returned from the sea and is doing a sky call. Sky calls are often described as high pitched screaming brays. Sky calls happen during socializing. Here you can listen to the sound of the sky call.
In this instance, LGL is announcing to her chick that she has arrived. Eventually the chicks will learn how to do the sky calls and will do one in return and with the parents.
The chick turns around and recognizes her mother. The mother is moving her eyes and head over the horizon. The Albatross do this often as a way of checking their surroundings.
LGL is clacking away happily. The little chick has raised its bill and is doing a gentle clacking. As the chick gets older and is hungrier when the parents arrive, this action – the clacking of the bill – will become more aggressive. It is a way to stimulate the parent to regurgitate food to feed them.
LGL does not feed her chick right away. She wants to spend time with it. She talks to the chick, acknowledges its bill clacking, and does some preening of its down.
After some time, the pair stop and check their surroundings.
The mother starts preening the head of the chick very gently.
Then she preens its back and wings. It must be like going to a spa for a massage.
After LGL is finished preening her chick’s neck, she touches the chicks bill and stimulates it so that the chick will begin clacking and tapping her bill. LGL reguritates the rich oily liquid squid shake and gives her chick a nice long feeding.
The Royal Cam chick may be only forty days old but it weighed 3 kilograms three days ago. The Chicks are regularly weighed on Tuesdays once they reach a certain weight.
This chick loves those squid shakes and has grown so much that the parents can no longer brood it. The little one wants to be close to mom so it cuddles up under her beautiful wing and tail feathers.
After a bit of a rest, LGL and the chick both look around.
Another boat is coming!
Rain has started to fall and the little one gets as close as it can to its mother so it will stay dry!
The rain has stopped and LGL has spent the night with her chick. This morning she is alert. It is 5:45 am in Taiaroa Head, NZ and the boats are already passing.
LGL feeds her chick before going out to fish – to feed herself and to return to her little one. Such a great mom!
LGL looks at the sea and the wind. The chick is asleep and before it wakes up she is off to fish.
This year there are satellite trackers on the parents so that researchers and the public can follow their movements. This information has show that they are feeding very close to where the chick is waiting.
I will also add that the northern island of New Zealand experienced three very strong earthquakes on 5 March 2021. Those earthquakes and the tsunamis that came did not impact the colony of Albatrosses at Taiaroa head. They reside near the very bottom of the South Island.
Sometimes the Royal Cam chick has visitors when its parents aren’t there. Meet Henry the Heron. Henry loves to do his snake dance for the chick and he also likes to photobomb the Royal streaming camera. Hi Henry!
Thanks for popping in to check on the Royal Albatross chick. This nest is fun to watch and there is no stress. The NZ Department of Conservation keep close watch on all of the albatross making sure they are healthy. The little one is weighed on Tuesday morning NZ time. And here is the link if you would like to add this lovely family to your bird watching list:
Thank you to Cornell Labs and the New Zealand Department of Conservation for their streaming cams. This is where the scaps were taken.
The 38 day old Royal Cam chick at Taiaroa Head is having some time on its own as the ‘pre guard’ stage sets in. The parents are leaving their little one alone for various short periods. The satellite trackers on both Lime-Green-Lime (LGL, mom) and Lime-Green-Black (LGK, dad) indicate that they are fishing just off the shores of this peninsula near Dunedin, New Zealand.
LGL gave a sky call as she approached her beautiful little chick. The Royal chick had a really good feeding before LGL headed out to sea to fish.
After LGL left to go fishing around 9:30 NZ time, the little one kept itself busy playing with the nest, preening, looking around, and enjoying the sprinklers at the NZ DOC bring out to keep the chicks cool. This helps the chicks to not get stressed by the 25 degree Celsius heat (77 F).
And sometimes, when you are all alone, you have to defend your nest in case a stranger walks by! As the stranger approaches, the Royal Cam chick stands alert and begins clacking its bill mimicking precisely what its parents would do.
Chick is on alert!
And here comes Henry the Heron! Henry lives on Taiaroa Head and loves to photo bomb the Royal cam chick! Sometimes Henry even does a kind of snake dance with its neck. Henry would never hurt the little chick but he does love to come for a visit to check in on the little one. We will see him often before the fledge in September.
Where’s Solly? Solly is the 163 day old Eastern Osprey that was born on a barge in Port Lincoln. We checked in on Solly a couple of days ago and she was heading south from Eba Anchorage back to the Streaky Bay area. Well, Solly is now back in Eba Anchorage! Solly spent the night in the same marshy area as she did on her previous visit. You can see the green pin in the satellite image below. From that central point Solly has been busy going out fishing. It is always so nice to know where the birds are. These satellite trackers are quite amazing.
It is early March. The White Bellied Sea Eagles whose nest is in the forest of Sydney’s Olympic Park will not be actively undertaking nestorations for a few months but already they have come back to the nest to do some inspections. I wonder if Daisy the Duck making a deep hole for her eggs will cause them any extra work? Last night the bonded couple, Lady and Dad, spent their night sleeping on the ‘parent branch’ of the natal nest after checking out the condition of the nest earlier and making a list of what they needed to do.
The Kakapo Recovery had sad news. Uri was taken into care because he was unwell. He had lost weight and the team felt that he would improve significantly with regular food and some checkups. Uri’s blood tests looked good and he had gained weight. But Uri seriously did not like being in a building with humans. The decision was made to return him to the island and to provide supplementary feedings and check ups for him there. When the team showed up this morning to do their check up, Uri had died. Uri had no outward signs or symptoms of Aspergillosis, a fungal disease that affects Kakapo. A necroscopy will be performed to determine the precise cause of death. There are currently 205 Kakapo.
Aren’t they cute? Three little Kakapo chicks.
This is a link about the disease and the treatment that you might find interesting. The Kakapo in the video is such a sweetie as are all of these non-flying parrots. Everyone is working hard for their care and welfare.
Birds have developmental ‘milestones’ just like humans. Right now there are so many Bald Eagle nests where eaglets are already two or four weeks old. In others, the parents are incubating eggs. And there are others where the parents are only beginning to start working on the nests. You can see every stage of a Bald Eagles growth from the female laying the egg to their fledging from the nest on the many streaming eagle cameras. Every eaglet is different, just like people and their development will not happen on a single specific date.
Within the overall umbrella of bird development, you might remember Daisy the Duck (see previous blogs for more information on this remarkable little duck). This Black Pacific Duck laid her eggs in the Sea Eagles nest. We knew that the ducklings would jump from the nest 24 hours after hatching if we actually got to hatch – which, sadly, we did not. Those ducklings could see, forage, swim, and take care of themselves without help from the parent. Daisy would, still, gather them up and protect them during the night. Fully independent of their mother, those ducklings would have been ‘precocial’. In contrast, the eaglets are not fully developed, nor are they able to feed themselves, or fly down from their nest. Indeed, they are covered with fluffy down but are unable to regulate their temperature.
It takes from ten to thirteen weeks for eaglets to fledge whereas the ducklings do this at twenty-four hours. Eagles as well as all other hawks or raptors are ‘semi-altricial’. This means that they will be dependent on their parents for everything they need until fledge. Even after fledging, the parents will teach them to hunt and will provide prey supplements for them.
Until the onset of streaming cams, there was very little quantitative information on the development of Bald Eagle Nestlings. Today, there are cameras, often more than one, on nests around the world. You can, at any time of the day, watch Bald Eagles, Peregrine Falcons, Golden Eagles etc. at your leisure. The growing community of citizen birders has impacted the knowledge of avian development and behaviour considerably. We are, indeed, continuing to learn every day. Advances in satellite transmitters means that birds can now be studied after leaving the nest providing much information about foraging, distance from natal nest to establishing their own territory, etc. This blog today is general and non-scientific in its terminology.
Many look at the development of Bald Eagles through three stages: structural growth, feather growth; and behavioural growth. Others attempt to combine feather growth with behaviour and structural development into weekly goals. In fact, I have pondered over this blog and how to approach it for several days because there are different factors that impact development. One of those is gender. There are also studies that have shown that the levels of salt in the diet impact growth while others have examined the amount and quality of prey. We know from studying Red Tail Hawks that if you double the amount of prey and the eyases remain in the nest for several days beyond the average, they are better equipped to fly and hunt. Their overall condition is much stronger. For the purposes of our discussion, I have used evidence from the NEFL Bald Eagle nest in 2021 and the SWFL Bald Eagle nest in 2021 and 2017 (E9). There is one eaglet on the NE nest and two on the SW nest in 2021. The parents on the NE Florida nest are Samson and Gabrielle. Samson was born on this nest on 23 December 2013. He is a little over seven years old. We do not know the age of Gabrielle. At the SW nest, Harriet is in her mid-twenties and M15 is 11 years old. Both nests are located within close proximity to a city – Fort Myers and St Augustine. The Fort Myers nest is unique in that the D Pritchett family has a working farm on the land where the nest is located. They also stock a pond in close proximity to the nest specifically for the eagles. This means that there is always food available. Still, the parents bring in road kill as well as fish from the pond. The NE nest does not have this advantage but nest observations reveal that there is an abundance of food although the variety might not be the same as the SW nest.
Both E17 and E18 were born on 23 January 2021. N24 was born on 8 February.
The first week of their lives, eaglets are covered with fuzzy down. The proper term is natal down. They can sit up but it is difficult to support their heads and focus. You can see the white dot indicating the egg tooth. This will disappear later. They use the egg tooth to break through the thick shell. This is often called the ‘bobble head’ phase. Their heads are big and they do not yet have the neck strength to keep them upright at all times. Their eyes are adjusting to focus. Sibling rivalry might already have started. As the days progress, the eaglets will get the strength to hold up their head and balance it. They will also be able to focus with their eyes so they do not look like they are using their beak like a dart but with a moving target (often their sibling). While the bobble head stage is very cute, it is often a relief when the eaglets are more stable.
By week two, the eaglets will be observed crawling out of the nest bowl. They are not walking. They are crawling. N24 is using its feet and wings to help it get out of the nest cup and up to the pantry. It is five days old! Food is a great motivator! Samson has the little one ‘working’ for its dinner. This helps to strengthen its wings and legs. In the Captiva Florida Eagle nest, Peace climbed out of the nest bowl towards the food on day 2. The inclines of both nests are different. The parents present the eaglets with challenges to help them develop their strength such as stretching their necks, grabbing and holding food, working their legs and wings. It’s like having your own personal trainer!
The beak will begin to grow and the little ones should begin shooting the ‘ps’ out of the nest bowl by the end of week one or beginning of week two.
The eaglets are more observant of their world. They will have doubled in size from the day they hatched and their eyes and beak continue to develop. You will begin to notice that pin feathers are growing in at their wing tips. They will start to stand keeping their balance with these wing tips.
More feathers begin to appear on the shoulders and the back and the wing feathers are getting longer as the days progress. They are starting to wing flap and they will try picking up food.
N24 is twelve days old in the picture above and the one below. In the one below, you can also see the pin feathers right at the tip of the wing starting to come in. N24 is also standing for several seconds, getting its balance, and flapping those wings.
During the third and fourth week, a pattern of accelerated feedings and growth begins. Head and chest are still showing signs of some fluffy down but more dark feathers are starting to emerge.
The eaglets are actively preening those feathers to help condition them as well as to help stop what some say is an itching as the feathers grow in. There is more wing flapping and the eaglets stand with confidence and stability. During this time you will see attempts at standing and walking. They begin to make some effort at self feeding. They are eating much more at each feeding often lunging at the parent to take the food out of their beak. Many observers say that their crops appear like they could burst! These big feedings often result in the eaglets sleeping immediately after a feeding. This is a ‘food coma’. The enlarged crops are extra storage spaces where food is held before being ‘dropped’ to the stomach. Sometimes people call this accelerated growth period the ‘clown feet’ era because the feet seem to grow way out of proportion to the rest of their body. They will also cast pellets. Pellets are food that is undigested such as fur and bones. Pellets are compressed into a hard shape and regurgitated. This often involves coughing and sometimes the eaglets appear not to want to eat the day the pellet is cast. This level of peak energy demands appears to begin to wane after about five to six weeks.
Beginning around week five to eight, the eaglets often sit with their wings drooping (getting heavy). Hopping and flapping wings occurs more often. They are very interested in what is happening outside the nest. By the end of this period, they will begin to have more of their juvenile plumage colouration. They will be able to hold food and tear bits. They will begin to mantle food. Mantling is the covering of food with the wings in order to have the prey item to themselves. They will stand for longer periods of time and are able to walk easily by the end of the period.
From week nine to fledging. The feathers will become more defined over their entire body and they will stand for longer periods of time upright. They can stand easily on one leg. The hopping, jumping, and flapping of wings accelerates. They are self-feeding but the parents will also continue to feed them. They will now spend their nights sleeping upright like their parents with their head tucked under their wing. They can easily perch on the edge or rim of the nest and will be branching, hopping up to a branch and back down into the nest. Branching tends to occur from seven to ten days before fledging, generally.
It is always exciting to see the eaglet hatch and sad when they fledge. Unless there is a transmitter or bands, they fledge and there whereabouts often goes unknown. Once they are wholly independent of their parents, the juveniles need to find their own territory and source of prey. Sadly, fifty percent of all first year eaglets perish while ninety percent of all year two eaglets tend to survive. The average age of maturity for Bald Eagles is five to six years although there is a young sub-adult male who is incubating his first eggs with his mate in Minnesota right now.
Thank you so much for joining me today. Stay safe. Be well.
Thank you to the Eagle streaming cams at NEFL and SWFL as well as the D Pritchett family. The scaps came from their streams.
I wanted to check in with all of Daisy’s fans to let you know that she is such a brave little mother. From the last posting, you will know that Lady, the White-Bellied Sea Eagle who lays her eggs on this nest and who raises her little sea eagles, showed up this morning at 5:37:11. Previous to now, it was mostly ‘Dad’ that came to check on the nest. Once in awhile, Lady would join him. I was always worried about Lady. Dad is, well, older. Someone familiar with the nest told me that he is nineteen years old. And he is laid back. As long as the bird laying their eggs on his nest is not a threat to him, I don’t think he cares. But Lady is different. She takes on the mantel of really being the person in charge of the nest. And maybe she hasn’t been happy with the way that Dad has been unable to evict “the bird” whose eggs are on her nest! It also seems that until today, the sea eagles had not actually caught sight of the the culprit, the owner of the eggs. But this morning Lady saw Daisy. Lady’s arrival and Daisy’s urgent departure meant that they almost crossed feathers! It really was that close. And Lady was mad. She had her whole chest puffed up. Lady became frustrated because she could not pick up the eggs in her beak. And then she began to tear the down from the top of the nest. But, sea eagles do not like duck down! There is no way around it. It is a foreign material to them. They are used to sticks. Down has no weight and it sticks to the beaks. That simple fact stopped Lady from doing any more damage. She tossed the down and, in doing so, covered up the eggs so the Ravens and Currawongs wouldn’t see them. What a nice thing to do for our little duck!
This morning Daisy did not go into hiding. She is getting near to hatch and she has much more invested in the eggs. She did flybys around the nest quacking all the time. The sea eagles left and within twelve minutes, Daisy was back on the nest brooding her eggs. Within a few hours, she had moved all of the down back to the nest and positioned it to warm the eggs. Other than really strong gusts of wind and a few song birds come to visit, the day, until now, has been uneventful. It is nearly 2pm in Sydney.
If the sea eagles are at their roost on the Parramatta River, one or both of them will probably come again today to check on the nest. But the high gusts of wind might discourage them. We can only hope. Right now they are more of a nuisance that keeps Daisy for incubating her eggs but they do not appear to be destructive. Daisy is not a threat to them. If, however, they stayed for five or six hours and the eggs cooled off, this would be disaster. Or if they moved the covering, the other birds might come and try to break or eat the eggs. So, once again, it is much better for Daisy if the day is simply boring and uneventful.
The image below was in the earlier post. It is a picture of Daisy arriving back at her nest with her lovely down scattered all over the twigs and leaves.
This little duck is so marvellous. She goes about what needs to be done. It doesn’t take her long, using her bill, to rake the down that Lady has tossed all about, back on to her nest. In the image below Daisy is tucking it around the edges so none of the cold air gets in to chill the eggs.
Daisy is being tossed about and rocked in the wind and the old Ironbark tree is creaking.
Did you know that Daisy talks to her ducklings? She is constantly rolling the eggs and tucking in and the down and all the while she is clacking away at her little ducklings. She does not know if any of these eggs are viable but she carries on talking to them. Hers will be the first voice that they hear and the first face that they see. They will imprint on their mother, a Black Pacific Duck.
If all goes well, Daisy will jump from the seventy-five foot nest in the Sydney Olympic Park and her ducklings will follow. They will jump out, spreading their wings to slow their landing, and bounce like a puff ball on impact. They will straighten themselves and get behind their mom and follow her to water where they will forage for food.
I have mentioned the many obstacles that Daisy could face getting the ducklings to water. I understand that is about a kilometre to the nearest water. A very knowledgable friend of mine told me that she had seen ducks take their ducklings through parking lots and schools if need be to get them safely to a river where they will immediately be able to paddle about. Isn’t it marvellous? One day old and they can do everything for themselves. Daisy keeps them warm and safe at night. Amazing.
It is nearing 14:00 at the nest and there is a gentle rain. Daisy’s feathers are waterproof and the drops collect on the surface of the feathers. When Daisy preens she uses oil from an oil gland to coat and restore her feathers. In fact, you might have seen birds spending most of their time preening. Their feathers protect them from cold and heat but also allow them to fly and swim.
The rain stays on the surface. And, besides, Daisy is used to being wet – she’s a duck!
Besides the oil that helps to condition the feathers, the feathers overlap. Look at the image below. In addition, ducks have angled barbs on each side of the central shaft of the feather. Each barb has tiny, tiny little hooks help hold the feathers together. Someone told me that it is like velcro on each side. This means that Daisy is covered with a lightweight shell of feathers that protect her and also allow her to float in the water.
It is now approaching 14:45 on the nest and Daisy is showing no signs of leaving for a break. It is extremely gusty with occasional rain. While the rain does not hurt Daisy and it would roll off of eggs, I imagine that Daisy would much prefer to keep her eggs warm and dry. The wings might blow the feathery down clear from the nest and the nest cup might also get soaked if the showers increased in their intensity.
For now, our little duck seems just contented to let the nest rock and roll in the wind.
I want to thank Daisy’s increasing number of friends from around the world in joining us. It is wonderful to know that so many people who speak many different languages and live in varying different cultures, come together to watch the brooding of a little Pacific Black Duck who dared to make her nest in the tree belonging to the White-Bellied Sea Eagles.
We will look forward to having you with us tomorrow. It will be Day 17 of incubation! And so far, the little duck remains on the nest.
Thank you to the Sea Eagle cam, Birdlife Australia, and the Discovery Center for the cameras from which I took my screen images.
I was reminded yesterday that Daisy the Black Pacific Duck is not normally an inhabitant of the forest. She lives down by the water and would, at most other times, make her nest on the ground. She would shape grasses and other plant material into the egg cup or bowl. It is only once she has started hard incubation, that Daisy, like other ducks, will pluck the down from her breast and line the nest. She will continue to add plant material and down to the nest as needed, often replacing what others pull out and destroy.
This year, Daisy didn’t make her nest on the ground. Instead, her and her mate selected a very old nest in an Ironbark Tree in mid-December. That nest belongs to the White Bellied Sea Eagles whose territory is around the Parramatta River and the Sydney Olympic Park forest.
Daisy would have had many intruders if her nest were on the ground. But she would have been familiar with them and they with her. Because she is brooding her eggs in the forest, she is a curiosity. The birds and animals that live there do not know about ducks. They do know that it is the sea eagles that raise their young in this particular nest. Of the curious, one of the first was the the Pied Currawong who, unable to eat the exposed duck egg, threw a little mini-tantrum pulling out much down from the rim of the nest and tossing it over the rim of the sea eagle nest. Others who have come to the nest to check out Daisy have been the BooBook Owl, possums, Ravens, and Sulphur-Crested Cockatoos.
Today, the Rainbow Lorikeets returned. They are the most colourful parrots in the forest! They are ever so curious about the duck in the sea eagle nest! Oh, not just six or seven, but dozens of them! And Daisy was not sure she liked them getting close to her and her precious eggs. Rainbow Lorikeets are a medium sized parrot that are plentiful along the east coast and southern part of Australia. Unlike Daisy who has a bill, they have a beak. They are nectar feeders and are no threat to Daisy. But she doesn’t know that! And like any mother, she will protect her nest and her young as best she can.
At first, it was only three (one out of the picture frame). They were a little cheeky and one of them, totally curious as to why a bird they had never seen should be in the eagles nest, crept over close to Daisy. Daisy turned around in her nest and away from the pleasant morning she had been having and ruffled her feathers and readied to defend herself against birds that she had never seen also. She did not know if they were looking for insects in the nest or if they would harm her.
One of the rangers that researches the nest of the WBSE said that the Rainbow Lorikeet were there to give Daisy the Duck a lecture about not making a nest in a nest owned by sea eagles. But, alas, it is too late if that is what they are doing. Daisy is now on day 7 of incubation duties. She is devoted to her duties!
After all of the commotion – and it really was a boisterous affair – with the Rainbow Lorikeets everywhere, Daisy settled into a little bit of nest renovation. Remember the Curra and Dad the Sea Eagle had moved down off of the nest. Look at how far Daisy can stretch her neck. I had no idea looking at her that her neck could get so long. She also used her bill to help gather up some down and plant material that had scattered.
A bill of a beak? Ducks have bills. They are very lightweight. The exterior coating over the interior spongy bone is made out of the same material as our fingernails, keratin. And just like our fingernails, the keratin covering is always growing, healing over dents and scratches, but also maintaining its shape after much use. Ducks do not have to go to a nail salon for a trim!
After nest renovations, Daisy takes some time to do some preening. Daisy’s feathers are very important to her. She is a ‘diving duck’. That means that she submerges under the water to find food. For ducks like Daisy, it is essential that their feathers be in prime condition. Many types of birds spend up to seventy percent of their time preening, conditioning their feathers. Daisy’s beautiful feathers have grown very tightly. The feathers are stiff and are quite strong compared to the down. In fact, people used to use the feathers as quills to use with ink for writing. Daisy’s feathers grow close together and overlap one another. Look closely and you can see this. They make many layers that are weather resistant and protect our duck.
It is nearly 11am in the world of Daisy. Dad the Sea Eagle did not show up at dawn to try and catch the intruder using his nest. Daisy has decided to try and rest a bit. She is still very alert.
Will Daisy take time in the heat of the Australian summer to go and forage? Will she voluntarily leave covering her nest? Will Dad come at dusk? We wait.
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.
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.
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.
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.
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.
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.
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.
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 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.
They might all be on one of the towers including the nest tower. Still, on occasion, they go their separate ways.
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.
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.
Little J3 spent the night of June 14 on Rice, apparently alone. He flew back to the nest hoping to have breakfast at 7:46 am on June 15. Arthur quickly awarded him with a squirrel which he mantled with both feet. The little guy was really hungry and no one was there to steal his food! Great hawk reflexes though. A couple of hours later Arthur returned with a chippie. Full to the brim J3 spent the day lounging on the grating or the natal nest, sometimes sleeping on his favourite leaves. At sunset, he flew back to the Rice building where he spent the night. He was just waking up this morning, stretching, and sleepy.
J1 also spent a bit of time on the nest rearranging the oak leaves that Big Red had brought in but most of her day was spent on top of Rice where her and J2 received prey drops from Big Red.
Around 5pm she made her way to the trees in front of the Fernow Building. At one point it looked like she wanted to get to the nest and she began breaking branches to aid her flight. Very intelligent. She then changed her mind. When I left her last night at 7pm she was in the Oak tree preening and this morning she was with a squirrel in one of the Oak trees in front of Fernow.
J2 is harder to keep up with as he is our “stealth bullet baby”. J2 has amazing flying abilities. It is like he skipped the learning stage and went to advanced intermediate. Yesterday he was aggravating a bunch of robins near the old coop buildings on the Cornell campus.
It is now the morning of June 16 and all is well with the J family. They are fed by the extraordinary hunting skills of their father, Arthur, aged 4. Their mother, Big Red, aged 17, keeps a close eye on the chicks. I wish I was on the ground chasing them about in Ithaca but, sadly, not. Postings about their development and happenings will appear daily albeit they could be short.
In the meantime preparations are ongoing, around the world, for the very first World Albatross Day on June 19. Stay tuned for information on that event as well as the challenges that both the Red Tail Hawks and Albatross face living with humans and machines.