Last week I teased about a hawk even more rare than the Swallow-tailed Kite seen in Eastham, one that showed up as I was going to press. I doubt anyone besides me remembers what I said last week, and I often don’t remember either, but in the interest of follow-through, here we are. The hawk in question was found following a tractor mowing a grassland in a restricted area of Camp Edwards, so was not chaseable by us civilians. It was found by a base biologist named Sean Rigney, who eventually posted photos of a handsome adult Swainson’s Hawk looking down from a telephone pole, the first one ever seen on the Cape and Islands away from Provincetown.
Swainson’s Hawks hail from the western US, and have only turned up in Massachusetts about 15 times. We have about half a dozen records here on the Cape and Islands, but all are from Provincetown or North Truro – people in all the other towns apparently don’t look up enough. I’ve never seen one in Massachusetts, but I’ve seen some from the very small population that winters in agricultural South Florida, a few out west, and several hundred thousand of them in Mexico.
The mystery behind the eyes of this Swainson’s Hawk staring down from this telephone pole on the base, of course, how it got there. The reason I saw so many in Mexico is because almost the entire North American breeding population, spanning the western US and Canada, leaves each fall to winter in South American grasslands and farms. Some fly from Alaska to southern Argentina, the second longest migration of any raptor in the hemisphere after the Peregrine Falcon.
Back in my carefree seasonal biologist days, some 25 years ago, I was lucky enough to be one of the counters at the River of Raptors hawk watch in Veracruz, Mexico. Some 4.5 million raptors pass through there each fall en route to South America, including up to 800,000 Swainson’s Hawks. If you’re wondering how we counted them all, the answer is “very carefully”. After a summer eating normal hawk things, mainly small furry animals, Swainson’s Hawks spend the winter eating grasshoppers in the Argentine pamapas, including big agricultural areas. As a result, at least tens of thousands died from pesticides sprayed to kill those same grasshoppers back in the 90s, luckily leading to the banning of said pesticide down there.
So did this hawk get lost on the way from Argentina to Saskatchewan? Did it take a wrong turn in Alburquerque? We’ll never know. A few of these hawks really do their own thing. A handful veer east to winter in South Florida, and one Swainson’s Hawk has been famously wintering in Brooklyn, New York, for several years, where, for reasons known only to it, the bird returns each fall to take up residence at a recycling plant in a very industrial area. Given the annual seasonal flow of New Yorkers to Cape Cod, maybe this is that bird checking out the real estate.
This Camp Edwards bird so far has been a one-day wonder – no one has seen since last Tuesday. But keep your eyes peeled for a hawk that looks sort of like a Red-tailed Hawk but with longer, pointier wings, characteristic of long-distance migrators, and dark primary feathers, meaning the tips and trailing half of the wings are contrastingly dark. If the past is any indication, it will turn up in Provincetown if it’s still around – unless someone in one of the other towns decides to look up for once.
