March 30, 2007

3/25, Quick Switch

Sunday started with 30-40 minutes in the northwest of Central Park, but the only interesting sighting there was a yellow-bellied sapsucker in the North Woods. At 5:00 I was standing at Douglass Circle and looked up to see one of the red-tailed hawks perched on Gabriel's horn atop the Cathedral of St. John the Divine. She stayed put long enough for me to walk all the way up to the Morningside Park overlook just below.

Red-Tailed Hawk atop Cathedral

Then at 5:07, she flew off in the direction I'd just come from and was last seen near the Great Hill.

She? Yes, a close look at pix revealed Isolde's darker belly band. But where is Tristan? I wandered about in Morningside Park for 15 minutes but didn't spot him.

By 5:30 I was back up at Morningside Drive and parked on a bench across the street from St. Luke's. A few minutes later Bruce walked up and we chatted for a bit about his pix the day before which revealed that Tristan is missing a feather on his right wing. (A review of my own pix suggests that this has been the case since before March 15.) Bruce also gave me directions for finding the Inwood Hill nest, where he had just gotten some nice pix.

Just before 5:45 a hawk fluttered up to Gabriel's horn. A minute later it dropped down and alit on St. Andrew's hand.

Red-Tailed Hawk and Cathedral Nest

It looked around for a full minute.

Red-Tailed Hawk and Cathedral Nest

Red-Tailed Hawk and Cathedral Nest

I decided to walk around the corner to get a better camera angle. The next thing I knew a hawk was in the air, flying towards St. Luke's, then circling, circling, circling, and then flying back to the Cathedral and perching on Gabriel's horn.

Red-Tailed Hawk atop Cathedral Although it was obscured part of the time by tree branches and the roof of the hospital, I had enough a look for the idea of "missing feather" to register, ergo, therefore the hawk that had just alit on Gabriel was Tristan.

But then Bruce said that from his stationary position, he had seen that hawk flying from the nest had actually exited the nest, while the hawk on the hand had then dived into the next. It was a switch-off.

Or in other words, when I first arrived at the Cathedral, Isolde was just beginning a break from brooding an egg or eggs in the nest. Tristan was in the nest but because the nest is deep, couldn't be seen from street level. Then at 5:45 Isolde had returned and taken back over from Tristan. And once she was back in the nest, she couldn't be seen either.

So plainly egg(s) have been laid, and the questions arise when did brooding begin and when should hatching occur?

My last sighting of both hawks outside the nest was Thursday, March 15. On Sunday, March 18, I did see Isolde looking around from the nest, but it wasn't clear how long she was there before and after I saw her. Monday, March 19, was the day that I saw her in the nest after sunset and guessed that she was going to spend the night in the nest. On Tuesday, March 20, Isolde was seen standing in the nest in an odd posture that suggests she might be laying an egg. If so, egg laying continued through the week, as Bruce indicated that he observed a mating session on Saturday, March 24.

In any event, going by the 38-day average given for Palemale and Lola between "first sitting" and first hatch, and working from the March 19 sighting, this suggests first hatch at the Cathedral around Thursday, April 26.

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