English and Scientific names:	Great Black-backed Gull Larus marinus
Number of individuals:	1 adult or very near adult
Locality: LOUISIANA:	Terrebonne
Specific Locality:	Timbalier Island N 29d 04.659', W90d 31.646'
Date(s) when observed:	3 Feb. 2009
Time(s) of day when observed:	appx. 3pm
Reporting observer and address:	B. Mac. Myers III, Eunice, LA
Other observers accompanying reporter who also identified the bird(s):	Matt Benoit accompanied me, but he did not identify the bird, did not even have binoculars; did provide gps coordinates
Light conditions:	very good, the sun was more or less quartering from behind me
Optical equipment:	10x42 Eagle Optics, very good condition
Distance to bird(s):	originally a half-mile or more, eventually within about 35 yards
Duration of observation:	several minutes
Habitat:	gulf beach
Behavior of bird:	hen first sighted the GBBG was near to and directly compared with an adult or near adult LBBG. Even at great distance the bright yellow legs, paler back and wings, and smaller size of the LBBG were apparent. The LBBG flew while I was still quite distant; fortunately the GBBG allowed close approach and photos before flying off to the west
Description:	Directly compared with LBBG adult or near-adult. This bird was much larger--taller longer, bulkier. The mantle of this bird was very dark, near-black compared with the grayer back of the LBBG. The legs of the LBBG were conspicuously bright yellow; this bird's legs were not. At a distance they appeared pale gray, perhaps slightly fleshy. Once I approached closely, they could be seen to be dull, faintly pink or grayish-pink. The bill was large, with substantial gonydeal expansion, bright yellow with a red gonydeal spot. My impression was that the eye was light, but when I was really close I was concentrating on getting photos. The head appeared white, with no obvious streaking. In flight it showed the large white spot at the tip of the outermost primary; other details of wing pattern not observed, except that the outer flight feathers were only slightly darker than the rest of the mantle.
Voice:	silent
Similar species:	The combination of very large size, very dark mantle, unstreaked head, and pinkish legs should eliminate other contenders. Direct comparison with LBBG for size and mantle coloration was helpful.
Photographs or tape recordings obtained?	I began shooting photos while quite far away and continued to do as I approached to within about 35 yds. Two of the closer photos emailed separately.
Previous experience with this species:	almost annually in LA, plus many in n.e U.S. and maritime Canada.
Identification aids: at time of observation:	none
after observation:	none
Notes made from memory?	brief notes made in field; otherwise from memory and from photos
Are you positive of your identification? If not, explain:	yes
Reporter:	B. Mac. Myers III
Date and time:	9 Feb. 2009; 12:40pm