Nest and Eggs
1. Where is this nest located?
The nest is on a light pole about 80 feet above an athletic field at Cornell University.
2. Do the hawks use the same nest each year?
Red-tailed Hawks may or may not use the same nest from year to year. A pair may have a few nests in the area and may fix up two or more nests for the breeding season before they finally settle down and choose one. They may also build an entirely new nest. In 2012, Big Red and Ezra nested lower on the same pole than they had the previous year. In 2013 they moved to a new pole nearby. In 2014 they stayed in the same nest as 2013. In 2015 they returned to the 2012 nest.
3. Do they mate for life?
Mated pairs are monogamous and usually stay together for life. If something happens to one of the pair, the surviving member will usually find another mate. Red-tail pairs have courting displays in midair and sometimes hunt together as a team.
4. When were the eggs laid?
In 2012, Big Red laid the first egg on March 16, the second on March 19, and the last on March 22. In 2013 she laid eggs on March 14, March 17, and March 20. In 2014 the eggs were laid a little later on March 19, March 22 and March 25. Red-tailed Hawks usually lay eggs every two or three days until the clutch is complete.
5. How many eggs do Red-tailed Hawks lay?
Red-tails usually lay one clutch of eggs each year consisting of one to four eggs. Research shows that in the United States and Canada, clutch size appears to increase from south to north and from east to west. There is some evidence that the number of eggs produced depends on food availability. In 2012, 2013 and 2014 the Cornell hawks have laid three eggs each year.
6. How long does it take for the eggs to hatch?
According to the scientific literature, Red-tailed Hawks usually incubate their eggs for about 28-35 days. In 2012, the Cornell hawks’ eggs hatched 38-41 days after the first egg was laid. The eggs hatched on April 22, April 24, and April 26. In 2013 eggs hatched 40-42 days after the first egg was laid. Two eggs hatched on April 22 and one on April 24. In 2014 eggs were laid March 19, 22 and 25, they hatched April 27 and 29, taking 35 – 39 days to hatch.
7. No one is sitting on the eggs or young. Won’t they get cold?
It is normal for parents to leave the eggs and nestlings exposed now and then. In most cases, they don’t stay away long enough for the eggs or young to suffer harm. Red-tailed Hawks have evolved over millions of years to cope with variables such as harsh weather.
8. What happens if the eggs are damaged?
If only one egg is damaged, the parents generally continue to incubate the other ones. If something happens to the entire first clutch of eggs, early in the breeding season, Red-tailed Hawks will often lay a second clutch.
9. Why hasn’t one of the eggs hatched even though the others have hatched?
Red-tailed Hawks typically lay an egg once every two or three days until their clutch is complete. They start incubating as soon as the first egg is laid. The eggs laid first have a head start and hatch sooner than the ones laid last. In some cases, however, an egg may not hatch because it wasn’t fertilized or because the embryo didn’t develop properly.
10. What is “pipping”?
"Pipping" refers to the process of the chick initially breaking through the shell, using a hard projection on its bill called the egg tooth. The resulting hole is the "pip" that the chick then enlarges to finish hatching.
11. When the chick is still in the egg, how does it get air to breathe?
Oxygen gets into the egg through pores in the shell. Hawk chicks may take more than 12 hours to make their way out of the egg after pipping. They get their first big gulp of air when they pierce the membrane of the egg under the shell. Once they pip, they keep their bill close to the pip and the growing crack they're working on.
12. Which parent sits on the nest?
Mom and Dad share incubation duties, but usually the female is the one sitting on the nest all night. Males will bring food for females on the nest, but females also hunt and eat when they are off the nest.
13. How big is their territory?
Red-tailed Hawks generally hold a territory of 1.5-2.0 square miles, but territories may be larger if less food is available. According to local observations, Ezra usually hunts near some woods and a cemetery a few miles away, but he has also been observed catching prey on campus very close to the nest.
14. Doesn’t the nest get disgusting from all the blood and stuff? Can somebody from Cornell clean up the nest so the babies don’t get sick?
Parents often remove dead carcasses when the chicks are young, but dead prey is often left in the nest as the nestlings get older so they have a chance to pull prey apart. Nests are naturally messy, but the young have evolved to defecate over the edge of the nest.
Parents and Young
15. How can you tell Big Red and Ezra apart?
The female, nicknamed “Big Red” in honor of Cornell University, is noticeably larger, with a darker head, nape, and throat. She has a numbered band on her right leg. “Ezra,” named after Ezra Cornell, the founder of Cornell University, is banded on his left leg. He’s smaller and has golden-tawny feathers on his face and head, and a paler neck than Big Red.
16. How old are Big Red and Ezra?
Big Red is twelve years old. She has a unique numbered band on her leg, and the records show that she was banded in the nearby town of Brooktondale, New York, during her first autumn in 2003. Ezra is at least ten years old. He was banded in 2006 as an adult bird on Judd Falls Road near the Cornell campus.
17. How can you tell apart male and female hawks?
Male and female Red-tailed Hawks are similar in appearance. Adult females tend to be larger than adult males. Behavioral clues can also help you figure who’s who. For example, if you see one of the hawks laying an egg, you know she’s the female.
18. How old are Red-tailed Hawks when they have their first nestlings?
The average age at first breeding is not known. Though a few juveniles younger than two years old have been observed breeding, in general Red-tailed hawks usually don’t start breeding until their third spring.
19. Are the baby hawks boys or girls?
It’s difficult to determine whether the nestlings are males or females just by looking at them, but females tend to be noticeably larger than males as soon as three weeks after hatching. The only way to tell for sure is through DNA testing.
20. How can you tell the nestlings apart?
It can be hard to tell which is which, but in general the biggest nestling is the first one that hatched and the smallest is the last one that hatched.
21. Won’t the babies get smothered from the parents sitting on them?
The parents don’t sit down on the chicks hard enough to smother them. The chicks can breathe even when their parents are brooding them.
22. When will the young hawks get their juvenile feathers? When will they grow red tails?
Juvenile flight feathers usually start to appear between two to three weeks after hatching and soon replace the natal down. Red-tailed Hawks usually molt into adult plumage (including the red tail) at the beginning of their second year.
23. Are you going to name the chicks?
In 2012, hawk fans called the chicks C1, C2, and C3, "C" after Cornell. In 2013 the chicks were called D1, D2 and D3. In 2014 the chicks were called E1, E2, and E3. In 2014 we will see F chicks.
24. Are you going to band the chicks?
Banding birds with an individually numbered ring on their leg is a common practice in ornithology to mark and study individual birds. Special permits are required to band birds for scientific study. If the hawks were needed in a study, then we would consider banding them, but presently the birds are not part of a study and we do not plan to band them. In order to avoid unnecessary disturbance at the nest, banding nestlings is done only when scientifically warranted.
25. That baby’s crying. It sounds hungry! Why haven’t the parents fed it?
Although the parents may not be available to feed a young hawk right away, if you keep watching, you may have a chance to see them finally come in with food. As the young grow, they can eat and digest bigger meals, and the parents may stay away from the nest for longer periods of time. In cases of severe food shortages, it’s possible that some young may starve. However, the Cornell campus seems to have plenty to offer. In 2012 and 2013, the hawks successfully fed and fledged all three of their young.
26. Why do the parents keep bringing sticks and leaves to the nest when the babies want food?
It may be that occasional maintenance helps keep the nest in good condition.
27. How long until the young can see?
Eyes open when the young hatch, but it is unknown what their vision is like upon hatching and how long it may take to develop.
28. In general, what can I expect to see as the nestlings grow?
- Day 1: The chicks are unable to raise their heads and lie limp for the first few hours after hatching. They have down on their bodies and weigh about 58 grams (2 ounces). They depend on their parents to bring them food and feed them.
- Day 2: The young are active; they issue soft peeping calls, bounce, and wave continuously with their wings.
- Day 7: The bouncing and peeping begin to wane, and the young peck at prey in the nest. Sometimes the older chicks may peck at the younger ones. Viewers may feel distressed to see this type of aggression, but in nests where food is plentiful, this aggression usually subsides after the chicks are two weeks old.
- Day 10: Nestlings emit high whistling notes (usually in response to their parents overhead).
- Day 15: Nestlings sit up continuously.
- Day 16: Young become aggressive toward intruders.
- Day 21: Young will strike out with talons and wings.
- Day 30: Young begin to stretch their wings and exercise regularly.
- Day 42-48: Nestlings leave the nest.
- After leaving the nest: The young hawks will typically stay in the area. Their parents will continue to feed them for several weeks to months.
29. How old are the hawks when they fledge?
Red-tailed hawks usually leave the nest at about 42-46 days after hatching. In 2012, the Cornell nestlings fledged on June 6, June 7, and June 13, 44-51 days after the first nestling hatched. In 2013, the nestlings fledged on June 4, June 5 and June 12, 43-51 days after the first nestling hatched on April 22. In 2014, the nestlings fledged June 6 and 14, 40 to 48 days after hatching. The exact dates of fledgling vary from year to year.
30. How big are the nestlings?
When the chicks hatch they weigh about 58 grams (2 ounces).
31. Won’t the babies fall out of the nest?
Nestlings don’t usually fall out of the nest unless disturbed, such as if a predator attacks. Nestlings seem to know that they shouldn’t stray far!
32. Why is that big one picking on that little one?
This is a natural, well-documented behavior for nestlings of some bird species, including Red-tailed Hawks. In some cases, the aggression may be a way for the birds to tussle and hone their skills, such as when kittens or puppies in a litter tumble about and fight. In other cases, especially when food is scarce, aggression may result from competition for food. Usually the older siblings are bigger and may peck the younger siblings. During food shortages, the older chicks may be the only ones to survive. Fortunately, the Cornell campus seems to provide lots of food for the hawks. Aggression toward one another usually disappears within two weeks of hatching.
33. Will the nestlings be OK?
Sometimes behaviors that look alarming, such as repeated pecking, do not result in serious injury. In other cases, especially during food shortages, intense aggression may result in one sibling killing the other. Because prey is abundant in the area, we hope that all the young will survive.
34. Why don't you shut the camera off during displays of sibling aggression?
We understand that people often feel upset when they witness events in nature such as predation, fighting, injury, or death. If we observe serious injury and distress, we will redirect our web page to an interim page that provides information about what is happening and that enables people to choose whether or not they wish to continue watching. However, because this is a live cam broadcasting in real time, it possible that viewers will see upsetting events. Viewers must decide for themselves whether they are comfortable enough with this possibility. If not, they may wish to stop visiting the cam page. The hawk cam is an opportunity to see an intimate, 24/7 view of nature as it is. The lives of these birds have touched and inspired hundreds of thousands of people. As in real life, however, nature shows us beautiful and profound moments, as well as moments that seem tragic or difficult to comprehend at times. At the Cornell Lab of Ornithology, we look to nature as our teacher. We hope that you, like us, will choose to watch, question, and learn from what we see.
35. If a baby dies, will the parents eat it? Will they throw it out of the nest?
We’re not sure, since this circumstance has rarely been observed. We hope all the chicks will survive, but if not, we will all learn the answer by watching the cams.
36. If a baby falls out will someone from Cornell put it back?
It would depend on the circumstances. We would need to consider factors such as whether the young hawk can be safely captured; whether it is old enough to survive on its own with its parents looking after it; and whether it is injured and can be rehabilitated.
37. Do the parents look after the young hawks after they leave the nest?
Parents provide all vertebrate food for the first three weeks after fledging and may help supplement their youngsters’ diets for eight weeks or more while the young learn to hunt on their own.
38. Will the babies come back to the Cornell campus next year?
We don’t know. The movements of individual young birds are poorly documented and since the young are not banded, we may not be able to recognize them even if they did return to the area.
39. What happened to last year’s fledglings?
Sadly, on Friday, August 9, 2013, the Cornell Hawks community was saddened to hear about the loss of two juvenile Red-tailed Hawks on Cornell campus. One was found dead; the other was euthanized because of the severity of its injuries. Many Bird Cams viewers feared they were D1 and D3, Big Red and Ezra's oldest and youngest offspring. A small group of dedicated individuals embarked on a project to study the hawks' DNA to determine the birds' identities in 2014.
The injured hawk, confirmed last year to be D1, was taken to the Janet L. Swanson Wildlife Health Center, where she received the best possible, expert, care from Cornell’s veterinarians. Sadly, the veterinary team determined that the injuries to her legs and feet (possibly caused by an interaction with prey) were too extensive and severe to enable recovery and quality of life, and decided that it was best to euthanize the hawk. It was upsetting news, but we took comfort in knowing that she was no longer suffering and in pain.
Our heartfelt thanks to the staff at the Wildlife Health Center who cared for the hawk and who did everything they could to help her and keep her comfortable. Thanks to moderators, to BOGs (observers on the ground), and our cams community, for the outpouring of caring and support.
The dead hawk, confirmed last year to be unrelated to Big Red and Ezra, was taken to the Animal Health Diagnostic Center to determine the cause of death, which was thought to be a result of blunt force trauma and associated internal bleeding, likely from a collision. We do not know whether a collision may have occurred with a vehicle, building, or other object. Other than its injuries, the young hawk appeared to be healthy and in good condition.
40. What happened to last year’s E3?
The last Red-tailed Hawk nestling to fledge was E3 on June 2014. Unfortunately in the morning of June 15, E3 was injured in an accident. While resting on the roof of one of the Greenhouses over the road from the CornellHawks nest, the automated roof vents began to close. E3 was resting under one of these vents, which lowered very slowly. The young bird did not move out of the way and became trapped under the lowering glass catching its right wing. Shortly after the vents closed they opened and Cornell Facilities staff were contacted and immediately responded shutting down the motors to the vents. E3 remained on the roof of the greenhouse for the afternoon, standing, but with the right wing lowered. Eventually Victoria Campbell, a licensed wildlife rehabilitator and Cornell Lab of Ornithology staff member, safely captured the bird. She took it immediately to the Cornell Wildlife Clinic. X-rays revealed that the juvenile hawk had a break to the upper part of his humerus, the upper wing bone, just below the shoulder joint. After surgery and testing it was confirmed that the young hawk would not be able to fly well enough to be released back into the wild and in August 2014 he was transferred to the Cornell Raptor Program where he is now adjusting to life in the care of the program director and students. E3 is now appearing in public education programs around the local community and is a great ambassador for Red-tailed Hawks across America.
41. What do Red-tailed Hawks eat?
Red-tailed hawks have a varied diet that depends on where they live. In general they eat small to medium-sized mammals, but they will also eat birds, reptiles, insects, and carrion. Based on observations from the cams, the content of the Cornell hawks' diet may vary from year to year, probably due to prey availability.
42. Do they eat the bones too? Why do they eat the bones?
Hawks may pull the meat off of large prey and leave the carcass, but they swallow small prey whole, bones and all. Bones are broken down in the stomach to provide important nutrients such as calcium and phosphorus. Any indigestible parts of prey such as fur and undigested bones are regurgitated as a pellet.
43. Do they eat leaves?
No, hawks do not eat leaves, but they may use leaves as nesting material.
44. How far do they travel to find food?
According to local observations, Ezra usually hunts near some woods and a cemetery a few miles away; however he has also been witnessed hunting on campus very close to the nest.
45. How often do they eat?
Red-tailed Hawks forage throughout the day. When raising hungry chicks, they spend almost all of their time hunting to find enough food. In the winter a Red-tailed Hawk may need to eat the equivalent of about three to four chipmunks per day, and in the summer a nonbreeding Red-tailed Hawk needs about two to three chipmunks per day.
46. How do they get water?
Hawks get most of the water that they need from eating their prey, though hawks are sometimes observed drinking water.
47. That bird just threw up. Is it sick?
You probably observed it regurgitating or “casting” a “pellet.” When a prey item is swallowed whole, indigestible parts of prey, such as fur, bone, and tough insect parts, will form a pellet in a muscular area of the stomach called the gizzard and be regurgitated. Most raptors will cast a pellet every day, often before eating their next meal.
Anatomy and Senses
48. How big are the hawks?
Red-tailed Hawks usually weigh 1.5-3.2 pounds. They are 17.7-25.6 inches tall and have a wingspan of 44.9-52.4 inches. Females are up to 30% bigger than males.
49. Do hawks have a sense of smell?
Traditionally, scientists have assumed that most birds have a poor sense of smell because the area of a bird’s brain involved in smell is relatively small compared with the area found in mammals. However, recent research reveals that birds have a high number of active genes that are associated with smell. Scientists have also discovered that some species of birds can tell each other apart by smell. So, though we don’t have all the details, hawks probably do have some ability to smell.
50. What’s the white film that you sometimes see over the bird’s eye?
Birds have what is known as a nictitating membrane or “3rd eyelid”. This is a clear eyelid, closest to the eyeball. It is transparent and can close and protect the eye when hunting.
51. Do hawks have teeth?
No. Hawks swallow food whole or rip it apart and swallow pieces.
52. Why is the poop white?
Bird poop is actually brown. The white pasty excrement is uric acid, the equivalent to a mammal's urine. Mammals excrete waste as urea dissolved in urine, birds excrete it as uric acid, which has a low solubility in water, and so it comes out as a white paste.
53. Do hawks sleep?
Yes. When asleep they will close their eyes.
54. When it’s cold and snowy, are the birds in danger of freezing to death?
Red-tailed Hawks can tolerate very cold winter temperatures. Under normal circumstances, it is unlikely that a healthy hawk will freeze to death. It’s important for them to keep their feathers in good condition for insulation, and to be able to find enough food to maintain their body temperature.
55. Why is it standing on one leg?
It is perfectly normal for a hawk to stand on one leg while resting or roosting. They will sometimes alternate standing legs. They may do this as a heat-saving measure, keeping the raised leg warm against their stomachs, or as a way to reduce fatigue in the raised leg. Birds may also shift legs just to be more comfortable; in the same way a human will re-adjust their position!
More hawk facts
56. What predators are threats to Red-tailed Hawks? What other dangers do hawks face?
Most predators, such as Great Horned Owls, crows, coyotes, foxes, and raccoons, are opportunists and will take eggs or young from a nest if they get a chance. Parasites can also prey upon hawks, but usually not to the point of killing the birds unless they are very young or debilitated for other reasons. Once Red-tailed Hawks are adults, the main threats to their survival are from human-related activities such as collisions with cars, shooting, or being electrocuted by a powerline. Hawks are also subject to disease, infections, and starvation.
57. Do Big Red, Ezra, and their young migrate? When will they migrate? Where will they go? Will they stay together when they migrate?
Some Red-tailed Hawks migrate, but others remain in the same area year-round. Big Red & Ezra are often seen around their nest site in the winter, so they may stay in the Ithaca area. Young hawks without established breeding territories might be more likely to migrate than adults. It is unknown whether related hawks stay together when migrating.
58. The Red-tailed Hawks in my neighborhood look different than the Cornell hawks, why?
This species varies greatly in plumage. The color variations (called “morphs”) are light morph, dark morph (melanistic), and rufous morph (erythristic). The latter two morphs are common in the western United States. Most of the eastern Red-tailed Hawks are light morph, but even within the same morph there is significant variation. As you can see on the nest-cam, the two Cornell hawks look different, with Big Red having much darker coloration.
59. How long do hawks live?
Red-tailed Hawks have been known to live as long as 30 years in captivity, but most of them have much shorter lifespans in the wild. A huge percentage of Red-tailed Hawks die in their first year due to their inexperience. Some starve. Many are hit by cars, electrocuted by powerlines, or shot. The average lifespan in the wild is probably less than 12 years, though some live into their 20s.
60. Are Red-Tailed Hawks aggressive? How do they attack?
They can be aggressive toward other animals when defending territories and nests. Though their beaks look sharp, their talons are their main weapons.
61. Why do you often see hawks soaring in the air?
They probably soar to identify good perching sites and possible foraging areas. The perspective from a greater altitude may also give them a hunting advantage, as they are able to oversee a larger hunting area using their keen eyesight to spot the slightest movement below. Red-tailed Hawks can soar using very little energy by catching warm currents of rising air, called thermals. Their broad wings help them take advantage of these thermals during migration.
Cameras and Chat
62. Do the cameras bother the hawks?
No, the hawks usually ignore the cameras.
63. How long will the cameras stay on?
The cam will stream during the entire nesting season, as well as the rest of the year as long as we have the necessary funding to keep the cam streaming.
64. When will chat be shut down?
The chat will close at the end of the breeding season.
65. What type of cameras do you use?
We use the AXIS Q6035-E PTZ Dome Camera and the AXIS P3364-LVE Network Camera fixed dome with IR Illumination and remote focus and zoom.
66. Why is the nest so bright at night?
The AXIS P3364-LVE Network Camera has an infrared (IR) illuminator. Most of the cameras we use are IR sensitive, meaning they can see IR light. IR light is not to be confused with thermal imaging. The cameras can see IR light reflected off objects such as the nest, birds and eggs.
67. Does the light disturb the birds?
No. Hawks cannot see infrared (IR) so the IR illuminator does not disturb them.