City Kestrels

Or: The Importance of Falling Apart.

An intriguing passage in Bernd Heinrich’s The Nesting Season about German architects incorporating nesting spaces for such cavity nesters as Eurasian kestrels, jackdaws, and swifts, in new buildings got me thinking about Bob DeCandido’s project of tracking American kestrel nest sites in old buildings in New York City. In NYC, the nesting sites are usually in the decaying cornices of nineteenth century row houses. This is typical New York City American kestrel, Falco sparverius, nesting habitat. (Starlings also like spaces like this.)This nest site on West 17th St. in the Inner Borough was one I reported to Bob in 2009, after watching the birds zoom across the avenue, perch on a nearby balcony, and then zip one after the other into this hole.

Such grand ornamental structures are passé now, as tinny and bland glass and metal facade so many ugly-ass contemporary buildings. It’s only the inaction or inability of building owners who don’t patch up their cornices and thus inadvertently allow the kestrels’ unusual urban success. In rural and suburban areas, after all, kestrel numbers have dropped, in some places precipitously; among other reasons, nesting sites are harder and harder to find out there. Old hollow trees aren’t left standing, decrepit barns get fixed up, monocultural suburban developments are pretty much antithetical to life, etc.

The American kestrel is the smallest falcon in our region; they are smaller than blue jays, but with longer wing-spans. They are also our most colorful raptor. They have the bold helmet-like head pattern characteristic of many falcon species, but they also have rufous backs and tails; the physically smaller male birds have blue-gray wings and a wide black band on the tail. Because they are small and very fast, they largely go unnoticed in the city, especially in comparison to their larger cousins the peregrines, and the big red-tailed hawks, some of whom practically have Manhattan publicists. They’re the most common raptor in the city, but also the most elusive. (Recognizing the ubiquity, NYC Audubon’s logo incorporates a kestrel in its hovering hunting mode.)

I like to say these birds depend on both the ruins of 19th century architecture and 20th century technology, because they can often be seen perched on old TV antennas, which still dot many a rooftop in the city. (Look for the bobbing tail, a good field mark from a distance.) Of course, they will perch on whatever is available:Holes in cornices, abandoned barns, dead and rotting trees, wood piles, patches of bare earth, et cetera, it’s all habitat, baby.