Wednesday, April 12, 2006

Fordham hawks update

I just received some new info and photos of "Hawk-eye" and "Rose" at the Fordham Rose Hill campus. Thanks, Chris and Prof. Fleisher.

Hawk-eye visiting Rose at their nest



(Photo credit - Rich Fleisher)

Subject: new photos of hawkeye on the nest
From: Richard Fleisher

Chris and Rob,
 
I am attaching some new photos of Hawkeye on the nest. As I was looking at the nest today, I saw Hawkeye fly onto the ledge. In some of the photos you can see the other bird's tail feathers. I am assuming that it was Rose sitting on the nest and Hawkeye who flew onto the ledge, perhaps to bring her food although I did not see any prey being exchanged.
 
Rich

*********

Subject: Re: new photos of hawkeye on the nest
From: Christopher Lyons

If Rose stayed on the nest, what probably happened here was that Hawkeye was checking to see if Rose wanted a break, but she didn't need one yet. This is a commonly observed behavior at the Central Park nests. While it's essential for Rose's health and general well being that she get to fly and preen herself every day, she's now fully in the grip of powerful instinctive drives that tell her to stay with the eggs as much as possible. Several times recently, I've seen Hawkeye take over incubation in the late afternoon (around 4:30-ish), while Rose flew off. I saw the same thing happen at the Inwood Park nest the other week, with the male taking over for the female at around the same time of day. These breaks may last an hour or two, but sometimes they only last a few minutes. It'd be interesting to know if there's some kind of 'schedule' individual pairs adhere to, or if it's more of a random thing, with the male checking periodically to see if his partner wants a break. He also feels a strong impulse to sit on the eggs, but he lacks the vital brood patch. If she gets off the eggs, he takes over. If she stays put, he tries again later. No question who rules the roost at a raptor nest.

3 comments:

Anonymous said...

That looks like a very thin covering of twigs on the nest site. Is that nesting material sufficiently deep enough? I thought that was the reason why the Pale Male failed last year.

Has this particular pair nested successfully there before?

Rob J. said...

This is their first year in that location. Last year their nest was in a tree a short distance from the auditorium. It looks almost as if much of the nest is set back a little from the pigeon spikes. I'll ask Chris how it looks.

Donegal Browne said...

Do the pigeon spikes cover the entire nestable area as they do at Pale Male and Lola's Fifth Ave. nest, or is there an area without the spikes up there?

If the entire area is covered with spikes I too am concerned about the depth of nesting materials covering the spikes.

I'd be interested to know if there has been any digging behavior in the bowl of the nest by the Fordham hawks. This is a behavior that I've noted in the Fifth Avenue hawks repeatedly in the last two seasons.

It's been theorized that the spikes might be poking up through the lining of the nest bowl and the hawks are being cued to dig by them. This is behavior seen in a tree nest when a twig from the tree begins to poke through the nest lining. The hawks dig at it until it breaks off, solving the problem. Breaking off a pigeon spike is a much tougher endeavor.

Lack of depth doesn't necessarily mean failure in a Red-tail nest. Without spikes to anchor materials, Charlotte and Pale Male Jr.'s nest on the Trump Parc last season hardly looked like a nest at all there was such a dearth of interlocking twigs. In fact there was a real lack of material in general because assorted pieces would often blow off the corbel. But their second clutch of the season was successful.

In actuality we don't really know why the 927 Fifth Avenue nest failed last season. The suspicion was that as it was a first year nest failure, as had previously happened to Pale Male's first year nests on the spikes after a nest removal, that in the second year, all would be well. That, as we now know, has not been the case.

Questions now center on whether something about the newly installed cradle or the cradle in conjunction with the spikes may be contributing to failure.

Of course nest failures do sometimes occur from natural causes such as weather.

Therefore, we hope that once the Central Park Red-tails leave their nests for the season that the owners of the real estate involved will allow investigation of the nests. Facts might be gleaned that could put some of the conjecturing to rest or even suggest a strategy for correction.

Exploring urban nature, birds, birdwatching, birding, hummingbirds, butterflies, dragonflies, bees, hawks, raptors, wildflowers, trees, mushrooms, environment, binoculars, spotting scope