September 8th, 2007. Monterey Bay, CA.
Leach's Storm-petrel Oceanodroma leacorhoa. (1).
Images taken through Canon Powershot A540 using Leica 8 x 42 binoculars.
2) Note that the white rump does not wrap around over the rear flanks
towards the vent as would be expected in Wilson's Storm-petrel.
3) Gliding on bowed wings toward the main flock.
4) Rising above Ashy Storm-petrels.
5) Cropped and enlarged - rising above Ashy Storm-petrels. Shows pale upperwing crescent,
long hand and impression of buoyant "nighthawk" like flight manner.
6) Cropped and enlarged - Here (upper right) banking away above Ashy Storm-petrels,
with Black Storm-petrels towards to left of the shot. Again, note the long 'hands' with wings held
slightly bowed when gliding, not the stiff-winged impression that one would expect from Wilson's SP.
This bird was seen during a 'Shearwater Journeys' dedicated pelagic. We were approaching a large raft of Black and Ashy Storm-petrels when I noticed this bird from the stern. It had already flown past the bow and must have been pretty close to the observers situated there. In haste, I called the bird as a "white rumped storm-petrel" and followed the bird through my bins taking record shots with my Canon camera. In the field, I was certain that I'd seen a dark central divide through the white rump, the divide being broadest towards the tail. It flew more or less in a constant glide on slightly bowed wings before rising and joining the storm-petrel flock, and was then lost to view. Sadly, I couldn't get any other birders onto this one, but was assured by the guides on board that Wilson's Storm-petrel (about eight of which were seen that day) was the only real possibility. As I see hundreds of Wilson's in MA each summer, I was uncomfortable with leaving it there. The bird's flight manner and the fact that I'd apparently seen a thin divide through the rump in the field surely would seem to indicate Leach's. Unfortunately, the divided rump isn't quite visible in these digibin shots but the images taken at the scene seem to confirm my suspicion that this was a Leach's Storm-petrel.
Images taken through Canon Powershot A540 using Leica 8 x 42 binoculars.
1)
2) Note that the white rump does not wrap around over the rear flanks
towards the vent as would be expected in Wilson's Storm-petrel.
3) Gliding on bowed wings toward the main flock.
4) Rising above Ashy Storm-petrels.
5) Cropped and enlarged - rising above Ashy Storm-petrels. Shows pale upperwing crescent,
long hand and impression of buoyant "nighthawk" like flight manner.
6) Cropped and enlarged - Here (upper right) banking away above Ashy Storm-petrels,
with Black Storm-petrels towards to left of the shot. Again, note the long 'hands' with wings held
slightly bowed when gliding, not the stiff-winged impression that one would expect from Wilson's SP.
<< Back to Pelagics