English and Scientific names:	Great Black-backed Gull Larus marinus
Number of individuals:	1 adult, my guess would be female
Locality: LOUISIANA:	Terrebonne
Specific Locality:	Timbalier Island
Date(s) when observed:	7 Feb. 2008
Time(s) of day when observed:	9:40 am
Reporting observer and address:	B. Mac. Myers III Eunice, LA 70535
Other observers accompanying reporter who also identified the bird(s):	Richard DeMay
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):	excellent
Optical equipment:	10x42 Eagle Optics, good condition
Distance to bird(s):	within 50 yds.
Duration of observation:	10 minutes?
Habitat:	Gulf beach
Behavior of bird:	standing, walking, flying, nothing to remark on. This was seen during winter plover surveys. The bird was directly compared with LBBG and HERG
Description:	A large gull, distinctly larger than HERG or LBBG, but it was not a really massive individual--hence my guess that it was female. Very dark back, only slight contrast with darker wingtips. Head white with no apparent streaking. bill large with pronounced gonydeal angle. Eye pale. Legs pale, dull fleshy-pink; the webs of feet were darker pink. In flight the outer two primaries had a fairly large white spot at tips of those primaries.
Voice:	not heard
Similar species:	The size, pale eye, very dark mantle, wing pattern, and leg-foot color all fit GBBG and should eliminate Western Yellow-footed, Slaty-backed as well as Kelp or Kelp x ("Chandeleur") Gulls.
Photographs or tape recordings obtained?	4 photos attached
Previous experience with this species:	a fair number in LA, many in N. Atlantic. Some experience with all the likely confusion species except Yellow-footed
Identification aids:	don't recall, maybe Dunn and Howell
This description is written from:	notes at the time and photos
Are you positive of your identification? If not, explain:	yes
Reporter:	B. Mac. Myers III
Date and time:	2 April 2008 3:59 pm