Washington Square Park had a fledge late yesterday afternoon. The fledgling was calling its parents this morning and fending off squirrels. All was just as it should be on the first day of school.
In the afternoon, the fledgling was on an NYU building, the parents were nearby and there was still an eyass on the nest. The rain storm gave way to impressive skies, including a double rainbow.
I went exploring today to CCNY and West End Avenue.
No sign of eyasses at CCNY. The nest shows no slices, but does have a fresh set of leaves in it. Too confusing to figure out what’s up.
The West End Avenue nest has a single eyass. It turns out it had had three eggs, two of which has hatched, with one eyass dying shortly after hatching.
I’m a little late to the party, since these Peregrines have been on The Century for three years. But I was overjoyed to see the parents and their two eyasses on Saturday. The Century is located at 25 Central Park West between 62nd and 63rd Streets.
The nest box is on the eastern side of the south tower. For news about the hatching of the two eyasses, see The West Side Rag and the Gothamist.
(I am concerned about a picture in The West Side Rag. The pebbles in the nest box are much larger than the gravel traditionally used in nest boxes. Given that only two of four eggs hatched this year, the owners of the box might want to switch to a gravel approved for nest box use before next season.)
I got to see lots of wet hawks on my visit to Sheep Meadow Saturday afternoon. The eyasses are growing up and are no longer white puff balls. The parents were off drying in the sun on a tree on the north side of the meadow.
The biggest surprise for me was the appearance of a Peregrine Falcon. I had seen this hawk here in the spring, but assumed it was a migrant. I was presently surprised to learn it was a Central Park resident, nesting on 25 Central Park West.
At Fifth Avenue, the hawk watchers are asking what happens at every nest, when will the eyasses (young hawks on the nest) fledge (fly off the nest). To answer this question requires some basic science, some behavioral science and lots of luck.
The basic science is that we know that generaly hawks fledge after 42-46 days. For some reason this can be longer for city nests, say 45-50 days. We’re not sure why we have this variation. It could be that we can count hatches more accurately in the city or that building nests without the opportunity for branching activity by the eyasses prolong the period. Hawks also need to be physically mature to fledge. So hawk watchers look at feather growth but more importanly tail length to judge if a hawk is ready to go.
On the behavioral side, we look for lots of jump-flapping and movement around the nest. We also look at the temperment of the hawks. Like college age childern, some look like they are eager to move on and others look like they won’t move out at all.
But in general, seeing a flege is about good luck and putting in the time to be in the right place at the right time.
The eyasses at Washington Square Park are almost ready to fledge. They’re jump flapping and flying well on the ledge but seem to tucker out a bit too quickly to be leaving the nest just yet.
They’ve been hiding in the back corners, so don’t be surprised if you don’t see them when you visit. It’s easy to think at least one has fledged sometimes!
