Band-rumped Storm-Petrel, Hydrographer Canyon, Massachusetts, August 2005
While sorting through photos of storm-petrels taken on the BBC pelagic trip, I came across these, which are of a single bird. The bird appeared at 10:17 am and flew parallel to boat, which was moving at full speed, on the port side for many seconds and then pulled ahead of the bow, still on the port side, before peeling off. I was in the very front of the bow and didn't really see it until it pulled ahead of the boat. At that point it was flying in a broad zig-zag pattern, i.e., moving closer and then further from the bow. Within that pattern, the flight was pretty fast and direct, with none of the fluttering of a Wilson's or bounding of a Leach's (though I think identifying storm-petrels by flight style is somewhat overrated, since each species has more than one style). It was seen by several people in the bow who debated whether it was Leach's or Wilson's. I didn't hear anyone suggest Band-rumped. It looked too big for Wilson's to me, but I was too focused, so to speak, on getting photos to study the bird with binoculars before it disappeared.
Looking at the photos, I see silvery carpal bars that fade out well short of the leading edge of the wings, curved edges on the white rump patch which wraps down on the sides, and a fairly straight edge of the tail, all of which suggest Wilson's, but the wings look too long and pointed, and the feet do not extend much, if at all, beyond the tail. Is this a Band-rumped Storm-Petrel? That's what it looks like to me, but I hesitate to call a bird that was missed by 77 of New England's finest.
Postscript: I have received numerous comments on these photos, and almost all agree that the bird is a Band-rumped Storm-Petrel.