Thursday, December 22, 2005

Blakeman on the Well-fed Hawk

Pale Male with bulging crop
Photo by Lincoln Karim

Lincoln's photo today of Pale Male perched on a window railing above Fifth Avenue shows that he continues to eat well. Viewers will note that his chest, between his chin and belly band, is a bit swollen. He's just consumed an entire crop-filling meal. That happens only when the bird has captured a large animal. With our rural red-tails that subsist on voles, large gerbil-sized field mice, we seldom see this full crop on perched birds. A vole is a very nice meal, but it never causes the crop to bulge, as in this photo.

Only a pigeon or rat or squirrel is big enough

Even in the heart of winter, Pale Male is eating well, and Lola must be, too.
This explains the other photos showing the lifting of a large egg remnant on the 927 Fifth Ave nest. Our red-tails out here in rural Ohio aren't spending any time or efforts tending to nests. The rural birds have to concentrate entirely on finding and capturing their sustenance voles. Here at the beginning of winter they have only about eight hours of hunting time in the short early winter days. And for the last three weeks, Midwest red-tails have been hard pressed to find the voles. We've had continuous thick (for us, 3-5 inches) snow cover. The voles are scooting about joyously beneath the snow pack along their networks of runways that connect one softball-sized vole nest with others. The hawks simply can't find the voles as long as the snow persists, and it's getting tough out there for them. Owls have the entire night to hunt, about 16 hours now, and they can actually hear the voles walking under the snow. Our red-tails, however, have only their eyes, and unless a vole pops its little nose above the snow to see what's happening out there, the red-tails won't eat. And that's what has happened.

In the last week, I've made two several-hundred mile jaunts across Ohio, one to the west to Indiana, and another south into Kentucky through Cincinnati. In a normal winter, when snows last only a week or so between melts, the experienced red-tails hang around, not bothering to laboriously fly south beyond the prey-concealing snow. But this year, I'm seeing very few winter red-tails in northern Ohio. It's clear that the majority have headed south to areas with no snow, impelled by hunger. In February these old birds will start drifting back in, and will be on nests in March once again. This snow-caused exodus happens infrequently here, about once very decade or more.

If Pale Male were to pull out his cell phone and ask his rural cousins how the winter's going, they'd have stories to tell. PM, with a slight smirk on his face, would give account of his fruitful winter in Central Park. He might remark that there seems to be a lot fewer large vehicles on the streets, and for unknown reasons a lot of humans have stepped out into the winter weather and are jaunting all over, just like the summer. But mostly, Pale Male would say that as always, he and his mate are eating exceptionally well. His rural relatives would wish him well, still not comprehending how he can so agreeably disregard all those humans so close to him.

Pale Male and Lola have the time and resources that allow them to moderately tend the nest, a very good sign.

[Tomorrow: Blakeman on Red-tailed Hawks vs. Great Horned Owls].