Six of us gathered at Schenley Park yesterday morning in perfect weather for a bird and nature walk. (The sixth is taking the picture.)
First on the agenda was a look through my scope at the Pitt peregrines. Though we were half a mile from the Cathedral of Learning we could see one adult babysitting and two fluffy heads looking out the front of the nestbox. This is where the chicks were standing as we watched.
Inside the park, a pair of red-tailed hawks is raising three chicks about the same age as the peregrines. We paused on our walk to watch them eat. Best views are from here.
Scroll through Charity Kheshgi’s Instagram photos to see our Best Birds including the blackpoll warbler pictured above.
On 12 April my friend Charity and I saw a Cooper’s hawk building a nest. Yesterday we saw an adult in the nest, incubating. We wondered about the process: When did nest building end? When did incubation begin? Does the male share incubation duties? How long before the eggs hatch?
The answers are fascinating because Cooper’s hawks don’t follow the expected rules. In the quotes from Birds of the World, below, did you know? …
Cooper’s hawks are a “common backyard breeding bird in cities of all sizes.”
Male Cooper’s hawks do most of the nest building. The female stops by occasionally to check on his progress and helps a bit, especially at the end.
Nest-mates have multiple genetic fathers. “Cooper’s Hawks exhibit high rates of extra-pair paternity involving both territorial and especially non-territorial floaters.”
Only the female has a brood patch. She does most of the incubation. The male takes over for short periods while she eats.
The female broods the chicks for two weeks, about twice as long as peregrines do.
Meanwhile in southwestern Pennsylvania, great horned owls (Bubo virginianus) laid eggs in January/February and hatched young around the time of this video. Keep an eye out for activity above. As the owlets grow up their nests will become more obvious, even during the day.
Les Leighton had his camera set up at Canada’s Vancouver harbor when a drama played out in front of him. A gull zipped by with both a bald eagle and peregrine falcon pursuing it in flight. What was it about that gull that attracted two predators at the same time?
Watch the chase and notice the difference between the eagle’s and peregrine’s hunting techniques. Why did both of them give up?
Six of us braved the drizzle yesterday morning at Duck Hollow and were rewarded with an exciting visit from one of the Hays bald eagles. Connie Gallagher captured part of the action in photos.
It all began with two herring gulls on the mud spit, manipulating a large fish.
The gulls hadn’t made much progress opening the fish when they saw the male Hays bald eagle flying upriver toward Duck Hollow. All the waterbirds could tell the eagle wanted that fish. The ducks stayed put, the gulls quickly stashed the fish and flew up calling and complaining.
The eagle made three dropped-talon passes at the fish but it was too hard to grab in flight. Meanwhile the gulls divebombed him and chased him every time. That fish was stashed so tightly that the eagle would have to land to get it. But the gulls were relentlessly annoying.
Finally the eagle left and the gulls resumed their meal, watched by a crow.
It’s “Pip Watch Week” at the Hays bald eagle nest. Hatching of the first egg is expected any day now.
Bald eagle eggs hatch, on average, after 35 days of incubation. At the Hays nest this pair has hatched 15 eggs over the past nine years, averaging just over 36 days per egg. Their first egg of the season, laid on 11 Feb 2022, is due to hatch soon. 35 days is today (18 March), 36 days is tomorrow (19 March).
Our hint that it’s close to hatch time will be a hole in the shell — a pip — hammered by the chick who’s preparing to hatch. After pipping the egg it takes an eaglet as much as a day to break out of his shell. Read the step-by-step hatching process here.
p.s. Five miles away, the USS Irvin bald eagles have two eggs. The first was laid on 27 Feb so Pip Watch will start there at the beginning of April. Click on this link to watch the USS Irvin bald eaglecam. Approximate first hatch date there is 2/27/2022 + 35 days = 4/4/2022.
Despite distractions we humans can focus on just one thing if we want to. Birds of prey can do it, too, as seen in this video of a red-tailed hawk in Tompkins Square Park, New York. The hawk doesn’t care about squirrels or people or the ambulance but when he sees a rat …!
This ability to focus is called selective attention and was proven eight years ago in chickens. See this vintage article, Selective Attention in Chickens, with an amazing video to test your own selective attention.
Bonus test: After you see the video in the chicken article, try another test. (This test + answer lasts 3 minutes. The remaining 2 minutes show family & friends reactions.)
(photo from Wikimedia Commons; click on the caption to see the original. Videos embedded from YouTube)
In March red-tailed hawks conspicuously soar over western Pennsylvania. They take to the skies alone or in pairs to soar and dive and dangle talons. Sometimes they even scream.
What is all this soaring about? It’s a multi-purpose signal.
Soaring is part of hunting and migration of course, but in the spring it’s a way to claim territory, advertise availability to potential mates, and cement the pair bond.
What better way to tell other red-tailed hawks that a territory is already taken than by soaring above it? Adults do this alone and in pairs. Unwelcome red-tails are escorted away. “This is mine!”
A lone red-tail also soars to advertise for a mate saying, “This is mine and I need a mate to share it.” (I have no idea how they signal the difference between ‘stay away’ and ‘come here.’)
Before the female lays eggs pairs of red-tailed hawks soar to cement their pair bond.
Prenesting displays typically consist of both birds soaring in wide circles at high altitudes and the male performing maneuvers similar to the Sky-dance [in which the] bird dives steeply from high altitude, checks descent and shoots immediately upward at similarly steep angle.
After several series of dives and ascents, the male slowly approaches the female from above, extends his legs and touches or grasps her momentarily. Frequently, both birds dangle their legs during aerial maneuvers. The birds may grasp one another’s beak or interlock talons and spiral toward the ground. Piercing screams and quiet, raspy calls often accompany courtship flight displays.