Wedge-rumped Storm Petrel off San Diego, CA

[AndyB]

scroll down for photos:
http://www.socalbirding.com/2010tripreports/sandiego24oct2010.html

[Alex Lees]

scroll down for photos:
http://www.socalbirding.com/2010tripreports/sandiego24oct2010.html

The boat also had a mixture of different Leach's - including individuals of the nominate and both chapmani and presumed soccorroensis. For those unfamiliar with the southern Pacific Leach's complex; Chapman’s Storm-Petrel (O. l. chapmani) breeds on the Coronado Islands and San Benito Islands, Mexico, whilst Steve Howell (in prep.) is planning to treat the Guadalupe Island taxa as full species. This using the English names Townsend’s Storm-Petrel for the summer-breeding O. [leucorhoa] socorroensis and Ainley’s Storm-Petrel for the winter-breeding O. [leucorhoa] cheimomnestes.

As to their putative Wedge-rumped Storm-petrel, I don't think they have presented much information that rules out Townsend's; in pics of the latter some show white 'wrapping around' the vent to an extent no greater than the field-photographs of this putative WRSP show...

[tapaculo]

For those unfamiliar with the southern Pacific Leach's complex; Chapman’s Storm-Petrel (O. l. chapmani) breeds on the Coronado Islands and San Benito Islands, Mexico, whilst Steve Howell (in prep.) is planning to treat the Guadalupe Island taxa as full species. This using the English names Townsend’s Storm-Petrel for the summer-breeding O. [leucorhoa] socorroensis and Ainley’s Storm-Petrel for the winter-breeding O. [leucorhoa] cheimomnestes.
http://www.socalbirding.com/images/NAB_63-4_Leach_s_Storm_Petrel.pdf