[Maine-birds] Great Black Hawk subspecies

One new finding that I don't think has otherwise been reported, is that the bird has a new, replaced black rectrix with two white bands, a narrower basal band and wider band distal to that (this feather was a stub in August when the bird was in Biddeford). That tail pattern is characteristic of the Middle American subspecies Buteogallus urubitinga ridgwayi (found from Mexico south to Panama). The nominate subspecies is found from eastern Panama (recorded to Costa Rica) south through South America to northern Argentina. These have only one broad white basal band in the tail. The skin color in front of the eyes (lores) is gray or mostly gray on adult ridgwayi but yellow in nominate urubitinga. Immatures of both subspecies have gray skin in the lores; so this is not helpful on the Maine bird, which is grayish in the lores. In any case, the plumage suggests the bird is not of South American origin.

The Portland Great Black Hawk has four new inner primaries, new wing coverts, and other renewed feathers in the upperparts, signaling it is in transition from its juvenile plumage (at it was in April in Texas) into its second cycle (immature) plumage. Large raptors like this retain juvenile plumage for much of their first year; so it is likely the bird in Portland is at least a year old or perhaps a bit older. There is a record of Great Black Hawk north to the Rio Yaqui in Sonora (nw. Mexico) that occurred in April 1986 (S. Russell, The Birds of Sonora), which is the same month that our bird was first seen in s. Texas but even north of that record by a bit. Different coasts, but perhaps a pattern of dispersal long underrated. Even so, the bird's presence in Maine challenges what we thought possible for vagrancy among what are considered essentially resident raptors.

Let's hope this wonderful bird lives free wherever it chooses for as long as possible.

Louis Bevier
Fairfield

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