Saturday, July 22, 2006

Ward Stone on Pale Male: He's not too old.

Pale Male bringing twig to nest
Photo by Lincoln Karim

The long-awaited report on Pale Male & Lola's eggs

By the time the eggs retrieved on 6/13/06 got to Ward Stone at the DEC's Wildlife Pathology lab in Albany they were in too advanced a state of decay to test for microscopic development. A visual look showed no embryonic development. But no further fertility testing was possible. The egg material was then sent to two different labs for toxicology testing. The results were negative for all substances tested. That was it.

My first encounter with Ward Stone

I first spoke to Ward Stone in 1993. The management of 927 Fifth Ave. had taken down the nest that year at the end of Pale Male's very first [and unsuccessful] nesting attempt on the building. The removal was a violation of the Migratory Bird Treaty Act, a federal law. The hawkwatchers zapped the Fish & Wildlife service on the management, thus preventing them from removing it again. The rest is history. [A new Fish and Wildlife Service "Memorandum" that went into effect in 2003 allowed the building to remove the nest legally in 2004, in spite of the clearcut federal law-- but that's a different story, one you all know well.]

Anyhow, in 1993, after the nest had been removed and unceremoniously stuffed into a huge black plastic bag, I managed to retrieve a fragment of an egg from the mass of twigs. It had a considerable amount of old yolk in it. I carefully placed the egg fragment in a plastic bag, wrapped it in tissue and placed it in a box. As it happens my cousins from Schenectady, Helen and Frank Steiner, were visiting NYC that day. They didn't live far from the lab and agreed to deliver the box personally to Ward Stone.

Frank worked for General Electric [GE] then and was very familiar with the name Ward Stone. GE did not love Ward Stone, to put it mildly. He had done necropsies on a lot of wildlife that had ingested chemicals GE had disposed of improperly. This was important evidence in a big lawsuit against GE. Nevertheless blood runs thicker, as they say, and Frank cheerfully agreed to drop off the egg. In fact he and Helen were nature lovers and were happy to do their bit to help our hawks. [Frank died a few years ago. Helen continues to be a Pale Male fan and sends me clippings from the local papers whenever he makes headlines].

Back in 1993 it took quite a few months to get the pathology report from Ward Stone. Then, as now, Stone had an enormous backlog of wildlife remains waiting to be analyzed. Of course then Pale Male was just an obscure raptor, not "the most famous hawk in the world." So our egg had to wait its turn. I have a feeling that this time we got ahead on the line, thanks to Pale Male's fame, and Ward Stone's own personal interest in the Fifth Avenue nest. After all, he's been closely involved in the story many times over the past 13 years. For example, he's the one who analyzed the remains of First Love, Pale Male's first mate, who disappeared in 1992 and amazingly reappeared in 1996. She became Mom II and raised 3 chicks in 1995 and 2 in 1997,. Then on Oct 12, 1997, she was found dead on a ledge of the Metropolitan Museum of Art, a poisoned pigeon in her crop.

When the report from Ward Stone came in back in 1993, it was amazingly similar to the report we received this year. In '93, too, there was no evidence of embryonic material in the egg fragment, and negative findings in the toxicology series.

I had my first of many phone conversations with Ward Stone that year. Then as now I wanted more answers than the report provided. He couldn't give me definitive answers, but he did venture a guess. Knowing that Pale Male was probably no more than 3 years old, and considering the likelihood that this was his first nest, Stone thought that the nest failure was probably due to the pale hawk's immaturity. Many redtails fail in their first few nesting attempts. Ward Stone was probably right. As we know well, the nest succeeded in 1995, and every year thereafter, until 2005.

Conversation with Ward Stone this year

First we reminisced about the past, and about our first conversation in 1993 when he thought the light-colored red-tail might have been too young. I immediately raised the question: Thirteen years have passed. Is Pale Male too old now to be fertile. Is that why the nest failed last year and this year? He answered:

"Here's my guess. With humans we worry a lot about when sexual activity is in decline, as you can see with Viagra and that sort of thing.

My experience with wildlife over all these years is that they really remain capable of reproduction for a very long period of time. If you look at bird records you don't see a big fall-off in fertility. You find a lot of birds, a lot of raptors able to reproduce until they're quite old..

Pale Male is somewhere around 15, --now that's not real old. I have a record of a 27-year-old redtail female who was hit by a car right near where I grew up in Columbia County. Her ovaries were in great shape and it was clear that she had laid eggs that same season. And I've got a male who was 17 or so whose organs were moderately enlarged -- everything looked good

There's no reason to believe that Pale Male is ancient, no reason to conclude there's a reproductive problem . I'd call him a regular middle-aged male.

I asked: What might be the reason for the nest failure, then?

Ward was willing to speculate:

"There's only circumstantial evidence, but the weather might be involved. We've lost a lot of birds this year because of torrential downpours."

That, of course, does not explain last year's failure. I asked him what he thought about the "cradle" put up in January 2005 for the purpose of holding the nest in place. Stone answered:
"Well, it's metal, but it doesn't come in contact with the eggs does it? "

I tell him that the accumulation of sticks brought by the hawks last year and this still looks somewhat sparce. Perhaps there is some contact.

"Could the hawks be provided with more sticks somewhere nearby?" he asked.

I told him I doubted they'd avail themselves of any supply of sticks we left for them nearby, because they always break off living twigs from trees for nesting material. Stone was surprised to hear this.

"You think they're only going to take twigs off trees?" he asked.

"Yes I do," I answered, "I'd confidently say that every single twig in the nest has been broken off a living tree."

"That's interesting," said the Albany scientist. "I've often seen hawks come in with stick to a nest, but I've never seen where they get the twig from."

I realized, and not for the first time, how privileged the Central Park hawkwatchers are in what they're able to see in their urban enclave. The park is relatively small and there are many hawkwatchers about, ever on the alert for hawk activity We've seen Pale Male and his various mates breaking off twigs and taking them to the Fifth Avenue nest literally hundreds of times.. We've even seen them breaking sticks off ornamental roof garden trees on neighboring buildings.

I once had a conversation with John Blakeman, our delightful hawk expert from Ohio, in which he said he had never had an opportunity to see where redtails get the twigs they carry to their nests. I had never seen any information about this in any of the published accounts about Red-tailed Hawks either. It's amazing to think that at least in this one small area, we may know more than all the acclaimed scientists. Let's hear it for the amateurs.