Posts Tagged 'Sunset Park'

Kestrel Check-In

Check.All these shots are from this week. The last two were on Thursday afternoon. I saw the female feed on small birds, presumably House Sparrows, twice within an hour. She’s packing in the food for egg-laying: remember, an American Kestrel egg represents 11% of the female’s body weight.For raptor friends, the scrape cam is on at 55 Water Street, where Peregrines have been nesting for years now. But now they have a new camera, in color for the first time. It’s like the 1960s! (This is a screen-shot, fyi.) I’ve been checking in around 6-7pm and have seen some mating, some eating, some moving of gravel, as human commuters hustle towards their ferries down below. Thursday, one was still visible at 9:30pm, presumably roosting the entire night. Riveting.

Even More Sharp-shinned

As I was preparing to head out the door last Sunday, the dawn of DST, I glanced out the window occasionally to see if the Kestrels would show up at the crack of dawn. They don’t set their clocks forward, after all. A bird whooshed into the London Plain across the street and hop-skipped-flew up to a perch, its back to me. The sun had not yet hit the tree. And it was not an American Kestrel. Here’s the female Kestrel in the tree later in the afternoon for comparison’s sake. It’s amazing that these birds are using the same tree to perch in.Dawn’s first arrival was a — if not, as I suspect, the — female Sharpie.By the time I got outside, the bird had flown, but as I descended the moraine towards 5th Avenue, I caught sight of her again. Now the sun was on her.What a difference the light makes in how she looks! (All these photo opportunities make me covetous of a camera with a real lens.)

Sharp-shinned Continued


Raptor Wednesday

Sharpie! The little Accipiter, Sharp-shinned Hawk, Accipiter striatus.This was the bird who did not like our male American Kestrel back in the middle of February.But it wasn’t all sortie after sortie.This is a juvenile female. The males are substantially smaller: on average just a midge smaller than an American Kestrel, in fact. The one time I saw a male close up (I was looking through a picture window) I was quite surprised how petit he was. Accipiters have some of the greatest sexual dimorphism in birds: females are generally larger in raptors, but for these forest hawks, the disparity is substantial. There’s actually some overlap in size between a female Sharp-shinned and a male Cooper’s. Some more on this classic field question.

This common name, “Sharp-shinned” isn’t in the least helpful unless you have a bird in hand. (And with those talons, look out!) The “striatus” in the binomial means streaked.

Kestrel Mania, Part XXX

The American Kestrels were extremely busy yesterday morning. During Wednesday’s storm, I saw neither skin nor feather of them, as expected. But the male was out bright and early in the rich tones of dawn on Thursday.

He soon flew over to the chimney, and several minutes later the female landed on the nearby roof pipe. They mated. And then the female moved over to the chimney and for the next hour and a half, there were a minimum of nine matings and/or copulations. I was not watching for most of this time, so I expect it happened a lot more. Between bouts, they preened themselves side by side on the rim of the chimney pot, dragging primaries and tail feathers through their bills, gnawing away at their breast feathers. I had not seen them so close together for such a long period before yesterday. [Some preening from Tuesday.]

While the pair were on the chimney pot, I noticed another Kestrel on the top of the car service antenna at 40th/5th. This is about 3/4s of a long block away from the chimney. This one was a female, making yesterday the only day in these weeks of Kestrel watching when I’ve seen two females at the same time. There didn’t seem to be any interaction between the pair and the solo female.

Both Peregrines were on the Industry City smokestack yesterday morning, too. There was a whole week where I didn’t see them at all up there.

Both the smokestack and the local Kestrel chimney are pumping out hot air. On cold mornings, this must be welcomed by the birds. The Kestrels will perch with tail inside the chimney as well as with tails out.

I put out a question on Twitter on the number of times American Kestrels typically copulate in a season. Matthew Kamm, a PhD candidate at Tuffs, graciously responded with recommending a classic monograph by Thomas G. Balgooyen, and sharing Balgooyen’s estimate of –wait for it — 690 copulations per clutch, with particular intensity 2-3 weeks before nesting.

I’m having trouble tracking down the book, but here’s a sample on the importance of pre-nesting behavior: “Mate choice, and the establishment and maintenance of the pair-bond between the sexes, is based on nest box inspections, important for sexual stimulation and establishing an acceptable nesting site; copulations that are important for fertilization and potentially inferring mate quality; and food transfers that demonstrate the male’s provisioning ability and help the female to achieve sufficient condition for laying and incubation.”

Dawn Kestrel

Sunrise on the American Kestrel male this morning, a few minutes before he and the female mated on their favorite roof-top pipe.

American Kestrel Update

Tis the season for copulation.Note how the male’s talons are bunched up. He can’t, after all, grab hold of her back with those sharp claws. I noticed this in an Instragramer’s photo of mating Osprey recently, where the scale was rather larger but the principle the same.
Bird mating is brief. The balancing act — flying in place essentially — and the fact that he can’t claw her are most conducive to making the process fast. Also, considering the high frequency of matings, are there a lot near misses for the requisite cloacal contact?



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