Tuesday, April 19, 2005

Blakeman answers Donna's Questions

Donna,

You asked for my comments on the Trump Parc nest, after an egg was reportedly seen rolling out of the nest on two different occasions. Apparently the birds resumed incubating after the loss of the two eggs. You asked, "What's up over there?

The peculiarities of NYC red-tail hawk nesting (and other) behaviors never cease. I've just never encountered a nest where eggs did or could roll out. That simply should never happen. Eggs often cool in poorly constructed nests, which are rather frequent in young, inexperienced pairs. But to have an actually egg role out of a nest belies some severe nest construction problems. It just shouldn't happen.

I don't know what could cause this other than inadequate construction by the adults. Might there be a local shortage of nesting materials? Perhaps, but if so, the nest shouldn't have been constructed in the first place. If the nest were poorly assembled, it should have fallen apart early on, before eggs appeared. More importantly, the sitting parents should have detected the nest's fragility and inserted some restorative twigs and sticks. Why didn't they? I don't know. Once again, weird, from a wild rural red-tail's standpoint.

If red-tails could talk, could you imagine the conversations being passed among successful adults out in the country side? "Hey Wilma, did you hear the one about that kid and his mate who tried to build a nest on some building down the Hudson in that big city? The eggs rolled out of it! Can you imagine? Stay away from the city. Who knows what will happen to a hawk that tries to live down there. The eggs rolled out of the nest! It's shameful. Are they related to anybody you know? Hope not."

Apparently, an egg remains. Otherwise, the pair would no longer sit. Let's see what, if anything else, happens.

On another subject, Donna, you asked if red-tails might not "imprint" to a particular nest type or location. You noted, quite accurately that eyasses imprint, or become psychologically attached, even fixed, on their parents, or whoever else feeds them. This can be an irretrievable problem when humans try to raise eyasses, as the little hawks quickly think humans are their parents. Things get very sticky when the eyasses start to fly and grab food from any nearby "parent," any human then see. But that's another story.

So no, I can't altogether discount a nest "imprinting" factor. Perhaps the eyasses do have a tendency to put their nests up on ledges two or three years later, when they start house (or nest-) keeping. Nonetheless, I really think remoteness and solitude, the absence of human and pet clamor and possible visitation by nest predators is most likely the reason the birds are way up on the side of New York City buildings. Notice that a number of hawks have first tried tree nests in Central Park, including Pale Male. I still think red-tails are predisposed toward tree venues, which they abandon after they individually learn that trees in Central Park seldom offer the peace, quiet, and perceived safety a motherly red-tail hen wishes for herself and her eggs and offspring.

Sincerely,

John A. Blakeman