Monday, August 15, 2005

The Perseid Adventures Part II: a small digression about robins

Synopsis: It's August 11th, the night when the meteor shower known as the Perseids is going to be at its peak. At a little after 4:00 a.m. my friend Naomi Machado and I meet at Cedar Hill, a vantage point chosen by our astronomy mentors, two friendly amateur astronomers. But as we settle down to watch we can see that the sky is covered by clouds. It doesn't look like we'll see any shooting stars that morning.

Before going on with our adventure, in the interest of disclosure I must admit that Naomi and I had an additional mission that morning. It was not shooting stars alone that had dragged us out of our beds at 4 a.m. We were also there to pursue a scientific study. Our subject of study was a common Central Park bird: the American Robin

. For almost two months we had been observing an odd phenomenon: just before sunset robins, hundreds of robins, quietly streamed into into a particular Linden tree on the north side of the Great Lawn.

That was pretty strange, it seemed to us, hundreds of robins flying into a tree. But stranger yet was the fact that all the arriving birds seemed to be males. How did we know? Well, male robins can be distinguished from females by the color of their chests.. The males' red breasts are a much darker and deeper russet-red; the females' fronts look a bit pale and washed out. No value judgement here. That's just the way it is.

Of all the thousands of people playing baseball, flying kites, having picnics, or just hanging out at this major Central Park gathering place, none besides us seemed aware that in their midst was a boys' dormitory for robins. Naomi and I loved having this little secret.

By the middle of May the dormitory dropped its single-sex rule. That was when the males began to be joined by increasing numbers of newly-fledged offspring. The kids could also be distinguished by breast color, for they had neither the rich russet color of their fathers nor the pale reddish tones of their mothers. they were completely speckled, like other members of the thrush family. At this point the dorm became a father-and-son or father-daughter club. The addition of the youngsters made the numbers of birds going to sleep at the northeast end of the Great Lawn even greater. We watched the overflow move into another Linden just across the path.

Where were the Moms? It wasn't hard to figure out, for robins are known to have two and often three broods of young each season. The female robins were scattered throughout the park taking care of brood after brood of young. They were incubating eggs, and then feeding and grooming keeping the young warm and dry all night. All the while the robin menfolk, and later the kids from the first two broods of the year spent their evenings socializing at the northeast end of the Great Lawn, smoking cigars, or listening for worms in the ground or whatever it is that fathers and kids do when left to their own devices.

The whole area of birds' sleep is a vast unknown. Look in the index of any ornithology text book and you won't find an entry for sleep. For Naomi and me, this mystery activated our spirit of scientific inquiry. We began to take notes on the bedtime rituals of our fraternity-boy robins.We took notes on the progression of sounds that seemed to characterize their bedtime ritual--from a loud cackle-like call, to softer whinnies to a final chorus of kwick-kwick, kwick-kwicks. And then silence, as if all those robin sounds had been turned off like a faucet. We noted the changes that occurred when the guys were joined by scores of awkward, noisy fledglings.

After a while we realized that our observations were incomplete. We had spent many hours of observing robins going to bed at night. Now we had to find out what happened at night's end. When did the birds wake up in the robin dormitory? What kinds of sounds did they make. Did they fly out all in one big rush, or did they trickle out slowly?

We saw our opportunity when the meteor shower was announced and Cedar Hill was chosen as the best viewing spot. Cedar Hill, as it happens, is quite near the Great Lawn; ten minutes of leisurely strolling would get us to the tree. Here's how we imagined our morning: after pigging out on the spectacle of hundreds of fiery bodies streaking across the sky, we'd hurry over to the Robin Dormitory a little before sunrise, to check how the birds began their day.

To be continued