Saturday, May 17, 2008

Hawk questions

The Riverside Park nest, fallen, two days after 3 chicks found dead - May 13, 2008
Photo by Bruce Yolton -

While many Red-tailed Hawk nests in New York City have thrived this spring,, the two nearest to Central Park have had unfortunate outcomes. As most of you know by now, the three nestlings in the Riverside Park nest, so welcomed by all of us and closely watched by an eager group of hawkwatchers,  came to an unhappy end. First one, and then the other two were found dead on May 11, and the bodies were taken to Ward Stone at the DEC's Wildlife Pathology Lab near Albany.

Since there was a severe rainstorm lasting most of the day on Friday, May 9th, and the nestlings were no longer seen on Saturday, the first thought was that the deaths were the result of hypothermia. The nest was inundated, and the chicks died of exposure. John Blakeman gave his reason for this assumption in a posting here last week.

Ward Stone's preliminary examination found hemorrhaging of the lungs in all three nestlings. This could have been caused by the anticoagulant chemical found in many commonly-used rat poisons. We'll know if the young hawks ingested a toxic substance once the toxicology report is in . This usually takes a few weeks. BUT I don't know whether lung hemorrhaging is also a symptom of hypothermia, and whether that might still turn out to be the cause. I have a call in to Ward Stone to try to answer that question. In the meanwhile, it is too soon to jump to conclusions about whether the young were poisoned or died of more natural causes.

As for Pale Male and Lola, everyone in the world now knows that the eggs didn't hatch for the 4th time in a row since the nest was removed on December 7, 2004. A reader of this site, Hank Riley, has written in a reminder that I am also forwarding to Glenn Phillips at the NYC Audubon:

May 15, 2008

Dear Marie,
. .
I'm waiting with bated breath to
hear if any plans are being prepared for Pale Male/Lola egg retrieval and timely fertility testing I'm not sure with Pale Male still visiting the nest, but maybe this year it will be possible to get the eggs a little earlier than in years before. If that could be done it could answer, or whittle down the list of possible explanations, the question of why the eggs have failed this many years in succession. I'm hoping that the wheels behind the scenes are turning, and that when it is appropriate, an announcement will be made that a plan has been developed to retrieve the eggs in time this year. As you yourself said in March: "All we can do is keep our fingers crossed now. And if there's a failure, we must really make sure that the eggs are retrieved and analyzed quickly, not for rat poison traces, (that's never been an issue!) but for fertilization."