Tuesday, March 21, 2006

Lola checks out migrating hawks: Blakeman explains

Lola over the Model-boat Pond - 1/16/06
Photo by Lincoln Karim


Yesterday,[3/20/06] Lincoln posted this observation. "This morning Lola flew with two unidentified hawks for 45 minutes very high over The MSB Pond. During this time Pale sat on the nest showing no signs of concern."

This might appear to conflict with information that shows that nesting red-tails vehemently defend their territories and stoutly drive off any non-resident red-tail interlopers. This, they do. I''ve seen it many times, especially in March when unmated and immature red-tails that spent the winter to south are moving northward in the spring migration.

But Lincoln's observation notes that Lola was not so adamant in pushing out the two unidentified hawks. In fact, there is no conflict here. And Pale Male just sat there.

When nesting, and also even a bit when tending eyasses on the nest, resident red-tails strongly defend their territories. But the territories tend to be mostly horizontal, near the earth. Here in northern Ohio, nesting red-tails commonly have a territory of one to two square miles (or more). In a few prime habitat areas, with lots of unmowed meadows and high vole populations, territories can be a half square mile or so.

But in no case to the nesting adults tend to defend their territories against migrants passing sufficiently high over head. Just as Lola did, one of the residents will often head up to inspect any overhead hawk passing by at a moderate elevation of several hundred yards. This apparently signals to the migrants that this would not be a convenient spot to drop down and park or hunt. The resident's suggestion to the passersby is to continue onward to the north, without any loss of elevation. Please keep moving is the message.

According to red-tail social conventions, migrant hawks are permitted to pass high over nests and territories. They are not allowed to descend into the defended territory.Fly-overs are allowed. Fly-throughs will be driven off immediately. Lincoln described a classic March migration fly-over. Lola was up there conveying some serious social imperatives to the other hawks. She could see that they might want to drop into Central Park for a brief hunting stay. By her stern attitudes, she deflected these birds.

Today, they are somewhere up the Hudson, being greeted again by other sitting residents. In time, these birds will make it back to New Hampshire, Vermont, or finally into Quebec and begin their own nesting.

All the while, Pale Male was sitting there keeping the eggs warm while he watched his larger mate draw the territorial line in the sky.

Great stuff.


John A. Blakeman