Saturday, October 14, 2006

Can we send them back? article & PS

Knowing my interest in large flocks of grackles and starlings, .N.J. garden expert Judy Glattstein
sent me this clipping yesterday. It is dated October 14.
Starling flock (photo courtesy David Kjaer and
The flock is due to number thousands within weeks

From the BBC News:
Thousands of starlings are due to flock above Aberystwyth in the evenings over the next three weeks.

<>RSPB [Royal Society for the Preservation of Birds, the British version of our Audubon Society]Cymru said up to 20,000 birds are expected and it has set up a promotion event to urge people to photograph them.

They roost under the pier, making Aberystwyth the only town in Wales where they flock, the RSPB said.

However, starling numbers in Wales have fallen by two thirds since 1994 and the bird is on an endangered species list.

RSPB Cymru has a stall on the seafront on some evenings to encourage people to watch and photograph the birds as they flock, before settling for the night.

Event officer Joe Hawthorne, said: "Many people find it hard to believe that they are declining so significantly.

"There are only about three places in the UK where they roost in towns and Aberystwyth is the only town in Wales where they do it.

"It's an amazing sight when you see 20,000 birds moving around as one."

He added that although the starling was one of the commonest of garden birds, it's decline elsewhere has put it on the "red list" of endangered species.

A spokesperson for RSPB Cymru said: "The event that Joe is leading at Aberystwyth pier during October is one of our Showing People Birds events, designed to encourage people to get out and about and experience wildlife first-hand.

"This particular scheme is important because it highlights the plight of starlings."

P.S. from Marie
Thought: Our starlings are the same species as the birds in the BBC article. They are not diminishing here, not at all. They take over nests of native American woodpeckers and other birds. So couldn't we send a few million to our worried friends across the sea?

Friday the 13th

Yesterday [10/13] I came home to find a message on my answering machine from Starr Saphir, one of Central Park's most accomplished leaders of bird walks. Her voice sounded excited. She said:

I led a walk for the Linnaean Society this morning in the Ramble. We had stopped at the benches on the East side of the Azalea Pond, and were just heading for the Swampy Pin Oak when we saw a Silver-haired Bat! This was a Life Bat for me and for all of us. The bat was in the leaf litter on our left and then flew up to a nearby tree trunk where we all had a chance to observe it.
I think having a bat of any species is very nice on Friday the 13th, and I know a Silver-haired Bat is most unusual for Central Park. Thought you'd want to know.

Thursday, October 12, 2006

Rousing after the bath = happiness

Cooper's Hawk, Central Park, 3/05
Photo by Lloyd Spitalnik

In yesterday's post Chris Lyons described a Van Cortlandt Park Cooper's Hawk standing and meditating in a puddle. "My best guess is that the hawk came down for a drink, and stayed there a while because it simply liked the sensation of the cool water on its feet, " he wrote.

John Blakeman has some light to cast on Chris's puddle-stander. He writes:

About Cooper’s hawks: These birds MUST bathe, usually each day. They have a genetic or behavioral impulsion to get in the water and do a complete dousing. I'm certain that’s what Chris saw with the Cooper’s in the puddle.

The vast majority of Cooper’s hawks nests are found within just a hundred yards or so of a small stream or pond. These birds prefer to bathe each day, and after doing so will fly up into a nearby tree and carefully shake out the water from their feathers, similar to the way a dog shakes off the water in it’s fur after emerging from a swim. Falconers term this feather-shaking as “rousing.” A hawk that rouses is known to be in good health, feeling secure and un-threatened by anything in the immediate environment. A hawk that rouses is a happy hawk, and Cooper’s hawk that rouses after it’s bath is particularly happy – so much so that it often sits and contemplates life for a time. That’s about the only time that Cooper’s hawks just sit and ponder, when they are drying and preening themselves after the bath.

Wednesday, October 11, 2006

More Cooper's Hawk talk and a PS

Cooper's Hawk at sunset - 12/05
Photo by Cal Vornberger

A note just came in from Chris Lyons -- you may remember him from his comments about orange chest coloring on immature Red-Tailed Hawks. He is responding to John Blakeman's letter about Cooper's Hawks, which, in turn, was an answer to a query from Bill Trankle of Indianapolis. Got it? Good.

From Chris Lyons:
I enjoyed the exchange between Bill Trankle and John Blakeman, and I certainly concur that Cooper's Hawks are feisty unpredictable raptors, who will sometimes attack anything that moves. I once saw a young Cooper's Hawk join a group of crows chasing a Red-Tail over the marsh in Van Cortlandt Park, only to suddenly turn tail and fly back to cover, as if thinking "What am I DOING?"

However, I believe they do have a more sedate contemplative side. This past Sunday, we were walking through a little-trafficked corner of Van Cortlandt, when I spotted a medium-sized raptor on the path ahead of us. We were no more than 50 feet away, I'd estimate. The bird was a young Cooper's Hawk, and we realized it was standing in a puddle, while it stared off to the right of us, at nothing in particular that we could see. It was either unaware of or unconcerned by our presence (even though we'd been conversing rather loudly up to then, and continued to talk in more subdued tones while we watched it). No telling how long it had been there already, and we watched it for around five minutes before we moved a little too close, at which point it flew off to the right, and disappeared. A short time later, we saw it sitting in a tree, again staring off into the distance. My best guess is that the hawk came down for a drink, and stayed there a while because it simply liked the sensation of the cool water on its feet.

Unusual to see one hanging around on terra firma, but I've often seen one sitting in a tree perch for long periods of time. Energy conservation, not to mention hunting stealth (or digestion, after a hunt has succeeded), requires any raptor to spend a substantial part of its day more or less immobile--but Cooper's Hawks are certainly far less sedentary in their habits than Red-Tails. It may be humorous exaggeration to say they can't sit still for more than 20 seconds at a time, but sometimes hyperbole gets the point across nicely.

Did Bill Trankle's Cooper's Hawk have any chance at all of dispatching a fullgrown Fox Squirrel? It seems highly improbable, and it would unquestionably be dangerous for a Cooper's to try grabbing onto any mammal larger than a chipmunk (even the chipmunk's teeth could pose a threat). However, Cooper's Hawks have been known to prey on mammals much larger than a chipmunk, and there is an anecdote in Arthur Cleveland Bent's account of this species (From "Life Histories of North American Birds") that offers an intriguing explanation as to how they might be able to manage such a feat. M.P. Skinner, a very experienced naturalist, who contributed much valuable information to Bent's monumental work, witnessed this incident in Yellowstone National Park--
As I rode up the loop road through the aspens above Mammoth, I heard quick, frightened bird cries on either side, and I even seemed to sense the excitement in the air. I turned about to see what was happening and a Cooper hawk came shooting up the road past me, four feet above the road and going at great velocity. A Kennicott ground squirrel that no doubt had been attracted to the road by spilled oats, tried to cross the road only to be struck amid a cloud of dust. After striking the squirrel the hawk went on for six feet more before it could turn. Meanwhile the squirrel was stretched out in the road lifeless. The hawk came back and attempted to carry off its booty. But I dashed up at a gallop, and as the prey was too heavy to carry off quickly, the hawk had to drop it. I picked it up and found that only one claw had pierced the skin, and only a drop or two of blood had come out. So I believe that the squirrel was killed by the force of the blow itself.
It occurred to me that Skinner might have been mistaken as to the identity of the assailant--could it have been a Northern Goshawk? Unlikely such an accomplished hunter would have been an immature, and the adult forms of the two species are hard to confuse. A hawk much larger than a Cooper's would have no difficulty in carrying off a ground squirrel. In any event, the trust Bent places in Skinner's contributions makes it hard to believe he could have been so mistaken in his ID. The species most likely to be confused with the Cooper's Hawk is the Sharp-shinned Hawk, and that would be even harder to believe.

This is one isolated incident, of course, and the animal in question would not have been as large as a Fox Squirrel. Peregrine Falcons are known for using their ability to strike with great velocity from above, to stun or kill their prey--mainly birds in flight, not terrestrial mammals. Still, the principle is the same--immobilize the target by delivering a powerful blow from the air, thus avoiding a prolonged struggle which could lead to injury for the raptor in question. Easier said than done, I'm sure. But if the Fox Squirrel had been insufficiently alert, or had left itself in a vulnerable position for too long, it's conceivable that the Bill Trankle's Cooper's could have stunned it with a well-placed blow. One assumes this technique would require considerable practice, and perhaps only a small number of Cooper's Hawks ever become proficient at it--it's not likely that mammals ever make up the bulk of any Cooper's Hawk's diet.

It's much more likely, of course, that young hawk was not at all serious in its attack--merely indulging a strong instinct for aggression, or simply entertaining itself with a moving target. However, it could also have been 'testing' the squirrel--looking for signs of weakness, seeing if the animal would panic and leave itself vulnerable to the maneuver described by Mr. Skinner. For all we know, the hawk had never seen a Fox Squirrel before, and was trying to assess whether or not it was potential prey. The Cooper's Hawk didn't get its unfortunate reputation as a pirate of the barnyard (though probably preying on half-grown chicks most of the time) by being overly cautious and conservative in its hunting habits. With raptors in general, and accipiters in particular, the operative slogan often seems to be "L'audace, l'audace, toujours l'audace!"

PS from Marie:
Well, I'm a mammal bigger than a chipmunk, and I was once attacked by a Cooper's Hawk. True, I had wandered too close to a tree in which, unbeknownst to me, a pair of Cooper's were nesting. Nevertheless, if I hadn't dived to the ground as fast as I did, I might have made a nice snack for two Cooper's kids up there. [Just kidding. I know they would only have savagely raked my head with their talons.]

Tuesday, October 10, 2006

Blue Grosbeak update and correction

Who discovers a bird first is important in the birdwatching world. When I wrote about the discovery of the Blue Grosbeak last Saturday I had not been told that the bird was first discovered in the Wildflower Meadow by the renowned Starr Saphir and pointed out to the lucky birdwatchers who'd signed up for her Saturday morning walk. Word was then passed along to others. This is to say: Starr found it first.

Meanwhile, a report on e-birds this morning says that THE BIRD IS STILL THERE at the Wildflower Meadow. See Saturday's report for information on how to find it.

Please note that in spite of the name, immature Blue Grosbeaks in the fall are not blue, as Lloyd Spitalnik's photo [see above] of the immature bird in the Wildflower meadow shows. They are predominantly rufous in color.

Click on and then click on Recent Photos to see Lloyd's other great photos of this bird.

For more information about Starr's walks [they run through October, I believe, and then by private arrangement] call 212-304-3808

Monday, October 09, 2006

This hawk needs a shrink!

Cooper's Hawk at Jones Beach -- 3/05
Photo by Lloyd Spitalnik

In a message dated 10/9/2006 Bill Trankle of Indianapolis writes:
Marie, I have another question for our Ohioan hawk expert, Mr. Blakeman.

As you know I have a Cooper's hawk who regularly visits my feeders, but yesterday I saw a display that amazed me. While staring dejectedly out at my birdless yard, the Cooper's came flying in slowly and then tried to snag a good-sized fox squirrel off of the trunk of my yard's hackberry tree! Not only did he miss, but he proceeded to chase the squirrel around the trunk, flapping mightily to keep his altitude, until he'd done the entire circumference.

The squirrel didn't even look worried as it perched on a knot while the Cooper's landed on the crossbar of my feeder complex. He stood there for a few minutes eyeing the squirrel, and then he tried again! He even chased it higher into the tree until a second squirrel showed up and proceeded to chase the first one, completely unmindful of the hawk. Finally, the Cooper's flew off into the field behind my house.

What I'm wondering if John can address is whether this is common, or was that one desperately hungry hawk? I was actually hoping he'd miss the squirrel, because I'm not sure he could have subdued it had he nabbed it, and it might have done the hawk grievous harm.

Never a dull moment in my back yard!

Bill Trankle

I sent the question on to John Blakeman. He immediately responded:

Bill and Marie,

The mind of the Cooper's hawk is inscrutably insane. Coop's seldom do anything rational or with deliberate consideration. I'm certain that the hawk was not deliberately trying to capture the squirrel, which was one our giant Midwestern fox squirrels, not the rather smaller gray squirrels of Central Park in NYC.

My giant red-tails have a tough enough time dispatching a fox squirrel, compared to a Cooper's hawk with it's relatively tiny, bird-catching feet. The squirrel instinctively "knew" that the accipiter was not going to really try to grab onto it. One bite of the squirrel could have severed the hawk's leg. The Cooper's relatively weak legs simply can't puncture the squirrel's very tough skin, and the small hawk can't kill the squirrel by suffocation.

The squirrel had the good sense to know that the hawk wasn't going to latch on to the squirrel, so the tree rodent just sat there or conveniently scurried to another part of the tree without any perceived threat. The second squirrel joined in the encounter with the same perspective.

Of course, what was the hawk doing in its initial pursuit?

Because this is an accipiter, particularly a quasi-psychotic Cooper's hawk, there may be no rational explanation. I'm guessing that the frenetic hawk was an immature, lacking starkly red eyes and blue-gray overall feather cast. It was probably a bird of the year, with yellow eyes and brownish-gray overall body hue.

The bird's flight against the fox squirrel was probably a momentary behavioral diversion, an incidental flight against something moving or alive, albeit inappropriate. Cooper's hawks can't sit or contemplate for longer than 20 seconds or so. They are constantly on the move searching for small birds to attack. In this case, the hawk had scared off all the birds, and many have already departed toward Kentucky and parts south. The hawk was impetuously impatient, so it impulsively shot after the squirrel, the only living, moving thing that it could see for the nonce.

Again, Cooper's hawks are weird and irrational, always approaching the edge of their safety or physiological limits. Against small birds, they are superb. Against mammals, particularly anything larger than a chipmunk, they are unequipped.

--John Blakeman

Sunday, October 08, 2006


Part of the flock last winter --
Photo by Bruce Yolton

A few days ago I sent a note to Veronica Goodrich, the Personal Shopper at Bergdorf Goodman's whose dressing room looks out on the Grand Army Plaza. Last fall and winter, you may remember, I obsessively watched a huge flock of grackles and starlings as they arrived to roost for the night in ten small pear trees there. I wrote:

Hi Veronica!

Are the Grackles back ?

Today she answered:

Hi Marie,

Yes, the grackles are back. They arrive around 6ish, in both sets of pear trees on the south and north of the Plaza. Let me know when you can take a peek.

To be continued...