Monday, March 21, 2011

The Pales and the eggs

Pale Male & Pale Beauty atop 930 Fifth Avenue yesterday [3/20/11]
photo courtesy of PaleMale.com

Yesterday hawkwatcher Mai Stewart sent a query to Ohio hawk expert John Blakeman expressing concern that incubation had not yet begun on the Fifth Avenue nest. Below, a part of her letter and Blakeman's reply:

Hi John,
I've been getting a little worried that we haven't seen Pale Beauty producing any eggs yet -- she and PM are doing all the right things, yet they're only visiting the nest, not incubating eggs yet, while the RSP [Riverside Park] pair has had eggs for, I think, almost a week, at least.
Am I being too anxious? I thought I remembered Lola sitting on eggs by now -- do you happen to remember when she would begin incubating? Also, that the time for laying eggs was in March, which is fast coming to a close! . . .

Mai,
Take no concern about the tardiness of eggs from the Pales. Pale Beauty is doing all of this for the first time, and first-time nesters can be a bit tardy. I would expect --- normally --- for an egg to be laid this week, the third week in March. But I'd see no problems unless an egg weren't laid by the end of the first week in April. By then, it's probably too late, and the bird was simply not able to lay this year, mostly for immaturity (not lack of food).
But right now, I see no problem. The pair is copulating repeatedly, and that's usually a good indication that an egg will be on the way.
And she spends very little time on the nest because she's never had to use one as an adult. It's all pretty foreign to her experience right now. But when an egg starts to form and descend in her ovary, she will feel a new instinctive compulsion to settle down into the bowl of the nest. That may be the first sign that an egg will be forthcoming.
We'll just have to wait, allowing ovarian physiology to do its thing.

And no, her leucistic genes play no suppressing role in ovulation or any other associated function.
--John Blakeman

PS from Marie

Looks like Pale Beauty has won the naming contest. Among the many suggestions I've received in the last few days -- among them Pallida, Pale-issima, Pale Female, Pearl, Blanche, Lucy [in honor of leucism] (!)-- Pale Beauty had the most votes. The name also happened to be my own choice [having proposed it], though I needed a bit of support before officially using it.

PPS See Bruce Yolton's blog http://urbanhawks.blogs.com for more info on hawks and also Central Park screech owls in the North Woods.