The NYC hawkblogs have been abuzz lately, as the resident Red-tails start to spruce up their nests and get their freak on in anticipation of spring. This season has already seen some interesting data points trickling out of Manhattan, to wit:

1. There are now eight known active Red-tail nests in that borough alone, plus two more suspected sites.

2. When one of the breeding adult Red-tails went missing, presumed dead, a new male took up with the widow within days, indicating a good supply of unaffiliated youngsters in the area looking for their genetic big break.

Wikipedia gives Manhattan’s area as 58.8 square kilometers.  The University of Michigan Animal Diversity Web states that Red-tail breeding territories range in size from .85 to 3.9 square kilometers.  In theory, then, if every square centimeter of Manhattan were ideal Red-tail habitat, with sufficient prey to allow for the smallest possible territory sizes, the island could sustain some 69 pairs of Red-tails; but this is, shall we say, unlikely.  Using the upper end of the territory-size range gives us a total of 15 potential territories; even that is probably high, given that some areas of the city are probably so unfruitful that no Red-tail will even bother trying to hold them.  So most likely, taking into account the number of unpaired juveniles floating around, Manhattan is approaching its Red-tail saturation point.

Brooklyn has some famous Red-tails too, but it doesn’t seem as thoroughly blog-documented as “the city”; there are Red-tail nests in Prospect Park and Greenwood Cemetery, ably blogged by Rob Jett, but those are the only ones that leap to mind.  We’re bigger than Manhattan, though, and it’s absurd to suppose there aren’t more.  The Farragut Houses, where I spotted the pair of juveniles this winter, are not only adjacent to the small wooded portion of the Brooklyn Navy Yard but also not far, as the hawk flies, from Fort Greene Park and Commodore John Barry Park, which both have the kind of open-with-isolated-trees habitat that Red-tails dig for hunting.

Maybe I should go look around.  (As best I can.  The Navy Yard has guard dogs.)