Friday, April 27, 2007

Beginning the discussion about Pale Male & Lola

Pale Male brings fresh twig to nest on Thursday, April 26, 2007APhoto courtesy of

Aimee Van Dyne wrote:

Do you think it makes sense to just request that the building take the whole nest structure down? At least then Pale Male and Lola can begin a search for a new nest site (the Beresford?) and not waste any more time on the old nest.
So unfortunate!
Hope you are well,
Aimee Van Dyne

I answered Aimee:

We're actively pursuing the idea of retrieving the eggs much sooner this year, in order to see if they were fertilized. If the eggs prove to have been fertilized, that would providepretty good evidence that it's the "cradle" at fault. Otherwise, people say it's PM's age, and nothing can be done. Too bad they didn't do a microscopic study last year, [see Blakeman's letter below] but it may be that the eggs were too far gone by the time they were retrieved.

Anyhow, taking everything down probably won't help. Pale Male & Lola are likely to endlessly keep bringing sticks that would keep blowing away. That's why we chanted "Bring back the spikes!" at the protests in 2004. The "Cradle" must go, if it turns out that the eggs
were indeed fertilized, and the spikes must be installed on the ledge in the way they used to be. It'll take some doing to persuade the powers-that-be at 927 Fifth Avenue to do that. But there's a chance that they'll go along, if we can demonstrate that the cradle is at fault, not the hawks.

PS I doubt that our hawk pair would actually nest at the Beresford. They have been using it as an afternoon and evening perch for years, when the setting sun gets in their eyes on east-side buildings. My guess is that they want a nest facing west. not east--because of protection from NYC's prevailing winds which come from the north-east and our most devastating storms, the famed nor'easters.

Here's John Blakeman's letter. sent two days ago, explaining what's at stake in the microscopic examination of the egg material:


Unfortunately, as I understand it, the eggs were retrieved very late last year and the pathologist who received the retrieved eggs was only able to do a gross anatomical examination, not a cellular or tissue study. This did not determine the "ploidy" of the eggs. If the cells were diploid, they would have had a complete, double set of chromosomes, half from Pale Male and Half from Lola. If the cells were haploid, having chromosomes from only Lola, they would have been definitive evidence of Pale Male's impotence.

I'm not convinced that the lack of gross embryonic structures in last year's eggs indicated haploidy, non-fertilization. The eggs sat on the nest un-refrigerated for weeks before being retrieved. The delicate embryonic tissues could have enzymatically degraded, even without bacterial contamination. I believe that some biochemical tests could have been used to determine the former presence of an embryo. If the eggs were cooled from the start of incubation, the microscopic embryo would have never developed and couldn't be seen upon gross examination.

If all of this occurs again, the eggs should go immediately (within the present week) to be analyzed microscopically. All the cogent questions would then be answered. The putative involvement of pesticides is no longer (and in my mind, never was) a consideration. The real question asks if the eggs are haploid, that is, unfertilized, or diploid, fertile, revealing that temperature or rolling problems caused the failure.

Now let me cover my tail right here. The eggs may, indeed, be infertile. Pale Male may have passed his day of potency. Yet there is no present evidence for this. He is extremely healthy, behaves perfectly, and copulates freely. From everything I know about red-tailed hawks, the chance of his impotence is very low, a position I believe would be confirmed by the many who have bred diurnal raptors now for 20 years or more. Check with Dr Tom Cade or any of his experts at the Peregrine Fund. They've bred hawks and falcons from around the world and would confirm my views.

John A Blakeman

Note from Marie: Plans to retrieve the eggs are in the works. The DEC is cooperating and will request approval from the building. Virtually all the hawkwatchers I've spoken to, or heard from indirectly, are in favor of early removal of eggs. Everybody wants answers to the pressing question of what went wrong for the third time this year.

Here's a silver-lining note from a reader:

Doyle wrote:

If eggs don't hatch, the only positive I'd see is that PaleMale will not become so ragged and tired.
I remember seeing pics of Jr, after he was fetching meals for Charlotte and his 2 babies. He looked RAGGED AND RUN DOWN. And he's a youngster.

I think tending to a family at Pale Male's age could do him harm.

At the same time, if there are no babies this year, hopefully it's due to the nest structure and not something adverse taking place in nature. (besides old age.)