Wednesday, August 15, 2007

Blakeman Q & A

Photo by Bruce Yolton

Website reader Donna Caesar sent in a question about a photo posted on Bruce Yolton's site yesterday. I forwarded it to John Blakeman. Below is the question and Blakeman's answer

I saw Bruce Yolton's posting of the 888 Seventh Ave parents spending the night on 15 Central Park West, possibly the highest roost used by a RT.[] Now I know that when perching birds sleep, their talons lock onto a branch or something involuntarily so that they don't fall off while asleep. Whatever are they locking on to way up there???!!! It just looks like a tiny little ledge to me.I know that pictures can be misleading. I was just curious and it prompted me to write after all these years.

Blakeman replies:

If the toes are not wrapped around a branch, if the bird sits on a wide, flat surface, the toes can be locked into position. This keeps the bird from toppling over, much in the way a table lamp stays placed on a flat table. The toes, feet, and ankle articulations become all locked into place on the flat surface.
But on a windy night, I think the birds could be knocked over with a big gust. I think they either stay awake, or are able to instantly adjust their muscles to remain standing and firmly in place.
I've noticed many rural red-tails sitting on high, exposed utility poles right at dawn's first light. The birds obviously parked themselves up there at dusk the night before. But in every case, the night has been a very calm one. On windy or gusty nights the hawks never choose to sleep out on exposed perches.
The birds seem to be able to successfully predict and plan for the coming night's weather. If it's going to be windy, I never see them settle down on an open, exposed perch. They always go into a woods and disappear in there. I've never been able to find where they spend the night in the woodlots. I know they are in there somewhere, but their exact deep night perches remain unknown. I've always presumed that they park themselves on some horizontal limb on the downwind side of a large tree trunk.
But unlike the so-accommodating red-tails of Central Park, my wild rural birds simply won't allow the approach of an observing or photographing human. My birds simply fly into the forest and disappear. When the weather clears the next day, they fly out and take up typical open perches where I can see them, and they me.
The numerous night perch photos at are, for the most part, new to raptor biology. I'm not aware of any other photographic documentation of where and how red-tails spend their nights in trees.
But again, to summarize. When there will be no winds, red-tails often elect to perch and sleep for the night out on tall, completely open structures. Here in rural Ohio, they choose tall utility poles or dead tree limbs. But if winds are to occur during the night, the birds somehow discern this and head right into the forest. In the coldest, windiest winter periods they will sometimes park themselves on the downwind side of tall spruces or white pine trees, where the needles provide a degree of protection.
Interestingly, that's how I began my red-tail adventures. While still in high school, I noted a big red-tail flying right over my head one winter day while walking home from school in Fremont, Ohio, not far from President R. B. Hayes's estate. The bird flew into a giant spruce tree in a local park, where I enthusiastically turned my binoculars to observe the spectacle. The rest is history.
But isn't it interesting that, as it happens, I was first introduced to this species in the middle of a 50-acre park inside a city---not as big as New York--- but a city nonetheless, not a place where a red-tailed hawk would be expected, even in 1964.
--John Blakeman