Monday, December 08, 2008

NAME THAT BIRD and Does an Urban Red-tail Need a Greenspace to Make a Living?


Photograph by Francois Portmann, www.fotoportmann.com/
Professional photographer and NYC Hawk Watcher Francois Portmann discovered that a year ago, 12/20/07, he took a photograph of an immature (tentatively Cooper's Hawk) in nearly the same spot as the one he photographed in the last few days. Is this just a good spot to hunt or might these youngsters be coming from a resident Cooper's nest?
One more urban hawk question to investigate in the new year.
MANY THANKS TO EVERYONE WHO SENT IN THEIR ANSWERS TO NAME THAT BIRD.
Here is a selection of a few of the many answers. First off a piece by raptor biologist John Blakeman--
Donna,

All of the accipiters, except the immature, appear to me to be Cooper's Hawks. They all have real necks. Their heads are not squashed into the body, as is usually the case in with the smaller Sharp-shinned Hawks.

The squared tail feature is not always very accurate, especially when the bird is perched. The usually rounded tails of Coopers' Hawks can get worn down a bit and appear more straight-across, in the manner of a Sharpie.

Yes, the immature, to my eyes, is impossible to identify, other than being an accipiter.

And all of this is a wonderful raptor conservation story. Twenty-five years ago, very few Cooper's Hawks were seen anywhere in the East or Midwest. They were put on a lot of states' Endangered Species lists. On the basis of multiple lines of evidence, not the least of which are photos such as the ones you posted, show clearly that the bird has recovered entirely from DDT-caused suppression of its populations.

The bird was formerly thought to be only a wary denizen of woods and forests, uncomfortable with people or urban environments. None of us would have envisioned the bird's colonization and acceptance of any urban environment, whether a small town like mine out here in rural Ohio, or New York City itself.

As a raptor biologist, I have to constantly keep this in mind. What I think I know about hawks isn't always the case, and in the future, who knows just how modern raptors will change and adapt. In honesty, in 1995 when I first read of some aberrant red-tail occupying Central Park in New York, I utterly dismissed the reports as being from overly enthusiastic but ignorant New Yorkers. Who knows what imaginary natural phenomena hustling Manhattanites might tend to believe. A nesting Red-tailed Hawk in Central Park? Of all people, I knew better. I've been studying the species for 30 years and knew that this wasn't what these big hawks would do..

But as this species so often does, the NYC red-tails made me look to be the fool. I was wrong. The bird had the capability, even the intelligence, to enter the Big Apple and become a thriving citizen, just as the Cooper's Hawks, too have done.

--John Blakeman


Sally, who volunteers at a wildlife rehab center--
I vote Coopers-even with the apparently "squared" tail it is hard to tell from those shots and it would be a huge Sharpie, ?sharpie? and carolina wren. Are you giving prizes? :)


William of Nebraska, a long time birdwatcher—
Both hawks are Coops and Carolina Wren on the dickybird.


Jeff Jones, a Christmas tree farmer in Maine—
The big difference in the dark top of the head, the lighter neck, and that it has a neck in the first place, makes the adult a Cooper’s Hawk. The young one? I’ve no idea.


An Audubon member in Florida—
Thryothorus ludovicianus and Accipiter cooperii

On to THE CHELSEA RED-TAILED HAWK

Birdwatchers Elisabeth and James had seen their Red-tail at 7th and 8th Avenue and 20th and 21st St. I then emailed Brett Odom about where exactly he'd had his sighting in Chelsea, and I got a quick response. He'd seen her circling high above 23rd St. and Fifth Ave. and was walking east until he lost her. That isn't far apart at all. Definitely within the range of a single territory.

Brett also wrote--

Hey Donna.

I understand the dangers of all concrete areas for fledglings and the need for trees and other things to allow them to get off the ground and branch, but what about red tails without young? Don't they need a certain amount of green space for hunting prey, or have you seen a red tail territory in the city that is nothing but concrete and buildings?

Madison Square Park is a moderately sized park, but I wouldn't think it was big enough to support the dietary needs of a hawk.

Now that I know other people have seen the hawk in the neighborhood, I will keep more of an eye out for it. I didn't know if it was a one time thing, like a hawk just passing through on migration, or if a red tail had moved into the area for a longer period of time. I will let you know if I see it again.

Brett

I believe an adult Red-tail can make a living without a greenspace in the city if there is enough of a prey base in the area. Here's why.

Some urban hawks have the needed hunting techniques.

Of the pairs I've watched closely, they all do some hunting on the sidewalk. I have seen Pale Male Jr. hunt that way the most often. He nabs pigeons off roofs and out of the air. Sometimes when he and Charlotte sit on the ESSEX sign they are facing away from the park. They're hunting south..the building area.


I've watched Jr. circle above Columbus Circle. He then starts a swoop from height to a few feet above the south sidewalk of Central Park and grabs pigeons knoshing on the spilled oats of the carriage horses. I also saw him daily predate the pigeons on the sidewalk that someone fed on 60th street. But these birds also hunt the park for their squirrels as well as other pigeons.


A couple of years ago I got a report that people living at 43rd and 9th, in a place with a very small garden (with square footage smaller than most people’s living rooms) where they had placed a bird feeder, were trying to get the state or the feds or someone to get rid of the Red-tail that was eating the birds that came to their feeder. They of course weren't happy that molesting the hawk would be illegal. It turned out I was living across the street from a place where this Red-tail was spending a good bit of time driving these people crazy and I’d never seen the hawk.


This particular garden abutted the wall to a playground. Now this was a concrete playground, not dirt. It did have a few large London Planes but that was it for vegetation. I talked to the Park Ranger that was there occasionally and she told me that yes, she found the remains of pigeons on the concrete under the trees some mornings though she'd never seen the hawk either. This was also the case at the playground about five blocks away when I tracked down the folks that cleaned it.


This bird was eating in the trees, but as you know many Red-tails eat on buildings so the trees aren't a necessity.. There truly are no green spaces in my neighborhood and still there was a hawk making a living. After searching and searching from my 27 floor apartment, I finally saw her once. She was sitting on top of the Actors Studio on 44th between 9th and 10th in a spot that I would not have been able to see from the street.


Red-tails with this kind of territory would have to depend almost exclusively on the pigeon population, as there just are no squirrels. And the pigeons depend on people feeding them to survive. No greenspace.. If people stop pigeon feeding that will reduce the hawks who are able live in those areas in which pigeon is almost the exclusive prey. The hawks could adapt to night hunting rats. (The rats rarely come out at dusk because the sidewalks are too crowded.) Red-tails do night hunt bats in some parts of the country so you never know it is a possibility.


Come to think of it night hunting might be one of the reasons I didn't see this particular hawk. It may have been picking pigeons off while they were at roost in the trees and hunting rats in the playground as well. Though no one had reported finding any rat carcasses, I have to admit. The playground closes at night, but the lights remain on until morning or did the last I noticed.


As to water, it wouldn't be as readily available as it is in Central Park but RTs do live in desert areas. In some of the literature they posit that Red-Tails don't drink. They do. We see them do it in Central Park. The hawks would travel or would figure out a way to get a drink if they needed one so that isn't a heavy factor. It's the amount of prey that is the make or break issue for an area to be suitable to support a hawk or hawks.


If you’d like your hawk to stay around, you better hope there are some responsible and stealthy folks feeding the pigeons in Chelsea. But pigeons definitely need a good amount of available clean water to survive and are less likely to go long distances to try and find it. Dehydration is a big factor in urban bird deaths year round. So if you have a terrace put some water out for them. I do.

Donna


P.S. What is responsible pigeon feeding? Feeding early enough in the day and in a location where all the bird food is eaten before dark. No reason to subsidize the rat population. The city does very nicely at that by not requiring rat proof containers for the literally thousands of bags of garbage that sit on the city’s curbs for hours every night waiting to be ripped into and gobbled.

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