Thursday, March 03, 2005

A HAWKWATCHER PROVIDES DATA and JOHN BLAKEMAN RESPONDS

Hello John,

As per your past request I'd been keeping a prey tally
for Central Park Redtails. Currently the sample is still very small,
covering only some days within the last two months, it breaks down to roughly:
65% pigeon, 20% Squirrel, 10% rat, 5% unidentified.


Pale Male's pigeon hunting technique that I have most
often observed consists of nabbing pigeons out of
trees. Though there are many Hawkwatchers who have
observed the hawks for far longer than I and in all
seasons, who will have observed many other strategies
I'm sure.
. . .
As this is Central Park there is a good bit of
wildlife feeding, some of which goes on in the
environs of the Hawk Bench. I think that the feeding,
the birds vying with each other for that moments food,
may be a distraction that makes the pigeons more
vulnerable to attack. One of the ways we know that a
raptor is about to be sighted in our area, usually
from the west, is that the pigeons take off in a
flash, banking and wheeling over the model boat pond
sometimes just making the circuit a few times and
sometimes completely disappearing east of Fifth
Avenue. The smaller birds take to the bushes in the
area behind the bench for cover. (We also have a
Cooper's that sits in the area about five feet from
the ground in a small tree trolling for snacks.)

Pale Male will fly through the branches of trees, lots
of space between branches in some of the park trees,
particularly the London Planes, and seize pigeons that
have remained in the branches, I assume thinking
themselves hidden or hungry enough to chance it in
order to be closer, and therefore, get more of the
people supplied food sitting on the ground, before the
competition gets back.

And, on at least one occasion, I saw Pale Male glide
into the London Plane above the bench and seize a
pigeon before any of the other birds had seen him.
Needless to say the rest left in a hurry. John has a
great sequence of photographs that show Pale Male
grabbing a pigeon out of the top of a conifer.

Lincoln Karim who has watched Pale Male and his
progeny closely has observed Pale Male displaying
pigeon hunting technique to his fledged young in the
area where the Central Park carriage horses wait to be
hired. Not only is it a high tourist area where pigeon
snacks are often obtained but more importantly pigeons
congregate in the area to cadge the highly prized oats
meant for the horses.

Once again there is a food competition distraction for
the pigeons.

Early this year I saw a Red-tail come in low and grab
a pigeon that was standing on the curb with his head
leaning down in the gutter to get spilled oats from a
carriage that had just exited the spot.

As you have pointed out, Red-tails have many learned
hunting strategies to remember and I would say these
are examples as recently I've observed a Red-tail
repeatedly hunting pigeons on the wing to no avail.


The hiding youngsters brought to my mind that I've not
seen one juvenile pigeon in the park in three months.
In my Westside neighborhood, at 43rd and 9th, I always
see at least some newly fledged pigeons in the winter.
Pigeons being year round breeders, though of course
more prolific in warmer seasons due to weather, plus
more people are outside eating raising the pigeon food
options.
. . .

Sincerely,
Donna Browne

John Blakeman answers:

Donna,

WOW! This is the info I was searching for -- and not
all of it was expected.

I'll have to go back and carefully re-read your two
emails. The information is astounding. Here are a few thoughts off the top of my head, in no particular order.

The fact that Pale Male (and surely others) have
frequently plucked pigeons sitting in trees is a really new and astounding observation. I would have
never thought this possible, because it's difficult
for the big red-tail to maneuver among tree limbs, and because I would have presumed the pigeons would
have simply flown away at the sight of the hawk.
Apparently the pigeons erroneously believe that they are safe in the tree limbs. That's true for a pursuing falcon, which will never enter woody vegetation in a hunt.

It's becoming clear, as I mentioned in yesterday's
posting, that the pigeons of New Your City haven't experienced red-tail predation and don't have any
innate, instinctive cautions about the hawks, which
they do for the peregrine.

And I appreciate your observation about the
vulnerability of juvenal pigeons. That seems very reasonable to me. Young birds with little experience and
reduced flight powers could be vulnerable in a
number of settings. Our discerning red-tails, as they carefully peruse the local prey from a hunting perch,
must be able to determine which of those pigeons
down there aren't paying attention, or don't move very quickly.

I have no questions regarding the hunting of
squirrels. A squirrel on the ground is highly vulnerable to a plunging stoop by a red-tail. No questions there. The moderate hunting of squirrels is expected. RTs don't particularly savor squirrels, as they have extremely dense hides and can be hard to dispatch. They can also offer severe bites. Wild red-tails will take squirrels, but
only infrequently and judiciously.

From your observations, it appears (as I initially
presumed) that the pigeon is the primary prey species for NYC red-tails. Your information on how this
resource is accessed is crucial. Keep me posted.

Thanks much.
Sincerely,

John A. Blakeman