The mystery of Pale Male's and Junior's orange-chested kids
photo by Cal Vornberger - May 29, 2004
Fifth Ave. nestling, jumping
Photo by Lincoln Karim -- September 1, 2005
Trump-Parc fledgling [f], pondering
On the train back last night I checked my e-mail device and found an anticipatory message from John Blakeman. Here it is. After that, at last, a summary of what I learned from Len:
John A. Blakeman
What Len told me
First of all, Len provided a scientific name for that orange breast coloration that has characterized all Pale Male's nestlings since 1995, and that was seen on the 2005 Trump-Parc nestlings as well: Erythrism -- defined, in the American Heritage Dictionary, as "Unusual red pigmentation, as of hair or plumage." The dictionary accents the first syllable.
" I've handled thousands of redtails at the Raptor Trust," Len Soucy began in a phone interview yesterday morning, "many of them first year birds. I'm also a Field Researcher and since 1969 I've captured and banded at least 10,000 Red-tailed Hawks . Most of the redtails we capture are young hawks that have recently fledged and are making their first migration -- first-year birds.
"The great majority of the young redtails we capture and band are white-breasted birds. Similarly, the young redtails I see at the Raptor Trust, orphans or nestlings that have fallen out of their nests, are predominantly white-breasted.
Very rarely do I see an erythristic first-year redtail. Oddly enough, many of the injured redtails that come to the Raptor Trust as young birds and then stay for longer periods of time [because their injuries are too severe] -- many of these develop that reddish-orangish coloration as they get older. But they started out as white-breasted birds."
Although Soucy insisted that genetics is not his specialty,he was willing to speculate a bit about the mystery of Pale Male's offspring and their unusual chest coloration:
"I agree with Blakeman that it's purely genetic," he said. " And since Pale Male has had multiple mates since 1995, it would appear to be a dominant gene carried by the male. It doesn't make sense any other way."
He agreed with me strongly when I suggested that this common trait makes it more than likely that Pale Male Junior really is a direct descendent of Pale Male [though it is theoretically possible that he is not a son, but actually a grandson]. Len also gave me a few names and phone numbers of other hawk experts, some in the West, who might be more familiar with erythrism among redtail nestlings.. I'll let you know what I learn.
For years we Central Park hawkwatchers have been debating the relationships between Pale Male and the various other redtails we've seen making nesting attempts around the periphery of Central Park. Now we have a strong piece of evidence that at least in this particular case where the nest succeeded and the young were observed, a direct relationship exists. Pale Male Junior is almost certainly a descendent of the famous Fifth Avenue paterfamilias. The other redtails around the periphery are more likely to be offspring too, we have reason to believe; we'll have a stronger clue if any of their nests succeed.
Before I posted this report I wrote again to John Blakeman and summarized Len's information. Blakeman wrote another note:
PS from Marie
Punnett Square? Is that somewhere near Harvard Square? We obviously missed out at the Bronx High School of Science.