English and Scientific names:	Cory’s Shearwater (Calonectris diomedea borealis)
Number of individuals:	One worn/molting adult, presumably widespread ssp. borealis
Locality: LOUISIANA:	Plaquemines Parish
Specific Locality:	over blue water at Mississippi Canyon, ca. 34 mi. (28 nm) SW of Southwest Pass Lat-Long. 28 32 12.0 89 47 09.9
Date(s) when observed:	27 September 2009
Time(s) of day when observed:	~1:50 PM CDT
Reporting observer and address:	Devin Bosler Lancaster, PA
Other observers accompanying reporter who also identified the bird(s):	David Muth, Phillip Wallace, Dan Purrington, Dave Patton, Edward Raynor, Erik Johnson, m.ob.
Other observers who independently identified the bird(s)	none
Light conditions (position of bird in relation to shade and to direction and amount of light):	Partly cloudy sky with optimal midday sunlight. Sun angle high and backlighting not a factor.
Optical equipment:	Zeiss Victory FL 8x42 (excellent condition)
Distance to bird(s):	within ca. 25-30 meters
Duration of observation:	~1 min.
Habitat:	Open, blue water Gulf of Mexico. Floating Sargassum abundant. Water depth ~1,500 ft.
Behavior of bird:	The shearwater was only observed in flight as it streaked across the bow of the boat going E-W.
Description:	A large, long-winged shearwater with pale brownish-gray upperparts and entirely whitish underparts. Upperparts rather drab and featureless. Grayish head. Dark tail contrasting with pale uppertail coverts. Heavy, dull yellowish bill with dark tip. Somewhat buoyant in flight with slow, deep wing beats interspersed with glides. Wings held forward in slight curve during glide and swept back when arcing. A worn individual with apparent wing molt. Replacing old upperwing coverts and missing some outer primaries. Undersides of primaries not carefully studied in flight and unclear in photos, so nominate C. d. diomedea cannot be ruled out with certainty (though unlikely based on distribution/occurrence).
Voice:	Silent.
Similar species:	No similar, large shearwaters in GOM. Greater Shearwater is much darker above with a conspicuous dark cap separated by a broad, pale collar.
Photographs or tape recordings obtained?	Yes, photographed by Dave Patton, Erik Johnson, and Dan Purrington.
Previous experience with this species:	Very familiar with this species from seeing hundreds off the East coast from DE, MA, MD, and NC.
Identification aids:	National Geographic Complete Birds of N.A. (Alderfer et al. 2005), Albatrosses, Petrels, and Shearwaters of the World (Onley & Scofield 2007).
This description is written from:	notes made during the observation, notes made after the observation, memory.
Are you positive of your identification? If not, explain:	Yes, very positive.
Date and time:	Devin Bosler 6 October 2009 6:00 PM EDT