Wednesday, February 07, 2007

Blakeman about a juvenile redtail

Mai Stewart sends a letter to John Blakeman about a juvenile redtail in Central Park:

Dear John,

Lincoln's website today posts a pix of what appears to be a young RT -- yellow eyes, don't think I see any red tail feathers (the second-last pix, a great one of the hawk in process of eating a pigeon). I was a little surprised -- didn't know there were any young RTs still in CP. Could he (she) be just passing through?

However, having mastered the art of catching pigeons (and the taste for same), do we think this one is taking up residence in PM's territory?? I'd love to hear any thoughts you may have

Thanks so much for all your commentary!

Best, Mai

Blakeman relies:


For me, the appearance of an immature red-tail in Central Park in the winter is not unexpected. This is a bird that while passing through in migration in November, or perhaps while just wandering around the area in December or January, happened to notice the large flocks of pigeons.

Of course, except in Central Park, for hawks who have learned to expertly take pigeons, these numerous birds are not common red-tail fare. They fly way too fast and except for sick or injured pigeons, red-tails by winter have learned not to waste any time or energy trying to capture one of these fleet-winged wonders.

But as I've mentioned before, red-tails spend inordinate amounts of time sitting around and diligently watching everything that moves in the landscape. Some time in late fall or early winter while passing through, this red-tail parked herself in Central Park and couldn't fail to notice the flocks of pigeons on the ground. As a diligent (and surviving) young red-tail, she scrutinized the flocks she saw down on the ground. As Pale Male and his cohorts did previously, she probably discovered that a few young, inexperienced pigeons tended to be inattentive and tardy in rising with the flock when it flew away. The hawk may have then learned to sweep in with rapid stealth to grab the pigeon.

Or, contrarily, the hawk more naturally first noted an abundance of day-active rats that any hawk, experienced or not, could merely drop down upon and take with ease.

Either way, the hawk found Central Park habitable with its abundant prey. So, it’s spending the winter. Many of us both in Ohio and New York, if we can, often want to spend our winters in Florida or in warm parts to the south. Red-tails don' mind the cold at all. They seem to relish the thicker, cold air. Their only winter concern is available food, and this young red-tail has found that in the Park. She’s a dedicated winter resident.

Which of course, raises the question of territorial defense by both of the established pairs, the hawks at 927 Fifth Ave. and the other pair down at the Trump Parc nest. How does it happen that those birds allow the presence of this young interloper?
In wild areas, especially ones with lots of prey (which out here, are field mice, also called meadow voles, not rats or pigeons), resident adults will be quite tolerant of other, non-resident red-tails during the winter. If there is plenty of prey, territories are not strongly defended in early and mid winter. (I might add, contrary to the theme of my most previous post---that red-tails aren't very social---loose winter aggregations of red-tails can be actually a bit social, sometimes with several unrelated hawks of all ages sitting around a large field that is filled with voles. They all just tolerate each other, the lowest form of social behavior for territorial predators.)

This inter-social winter tolerance, however, will soon begin to dissolve. Very soon, the breeding hormones of the adults will be flowing, and neither pair is likely to abide the presence of this young hawk in Central Park. I predict that it will soon disappear, having been driven out of the park by some strongly suggestive adult body language. No adult is likely to actually attack the youngster. She'll get the message by the way Pale Male or Lola flies in her direction. "Git along now, little one!" will be the message. (Well, this is New York City. The language, perhaps might be, "We don't believe you should be here anymore. We're paying the rent now. It's been nice for the winter, but it's time for you to move along!")

So, I'd be pleased if CP hawkwatchers could keep us all posted on how long the immature stays in the Park. I think it will be displaced by March 1st, if not before.
And one last note here. Many will wonder if this winter residency might incline the bird to return to CP as an adult. It very well might, but in the interlude, it's likely to drift off many miles. Next summer, it will attain its red tail feathers and next fall and winter become a "floater," an un-attached young adult looking for a new mate, nest, and territory. If any of the CP adult red-tails meet their demise, this bird could be a replacement. In the meantime, however, it could drift all across the Eastern Seaboard.

As before and always, wonderful questions and observations. Keep them coming.

--John A. Blakeman

P.S -- By the thickness of the tarsus ("ankle") and toes of the hawk, I'd guess (just a guess) that it's a female.