English and Scientific names:	Glaucous Gull (Larus hyperboreus)
Number of individuals:	1 in worn first cycle plumage
Locality: LOUISIANA:	Terrebonne
Specific Locality:	Wine Island, Isles Dernieres barrier island chain (29.0955 N, -90.6108 W)
Date(s) when observed:	29 May – 18 July 2008
Time(s) of day when observed:	7:00 AM to 6:30 PM CDT
Reporting observer and address:	Justin Bosler Baton Rouge, LA
Other observers accompanying reporter who also identified the bird(s):	Edward Raynor
Other observers who independently identified the bird(s):	presumed same bird as reported by Cecilia Leumas on 11 May at East Island/Trinity Island. The possibility also exists that this is the same bird documented at Port Fourchon (Lafourche) between 31 Mar and 5 Apr (Guidry, Bosler, and Purrington)
Light conditions (position of bird in relation to shade and to direction and amount of light):	Light conditions varied from mediocre to excellent for most sightings throughout the period, but well studied in direct sunlight.
Optical equipment:	Zeiss Victory FL 8x42 binocular (good condition) and Brunton Eterna angled 80mm spotting scope (good)
Distance to bird(s):	As close as 50 meters.
Duration of observation:	Approximately 1-30 minutes on numerous occasions.
Habitat:	Barrier island sandy beach at interface of large bay (Terrebonne) and Gulf of Mexico.
Behavior of bird:	Usually seen resting or preening on beach w/ other larids, namely Laughing Gulls, Royal and Sandwich Terns. Sometimes in company of a few ratty over-summering Herring Gulls. Very, very skittish, maybe even more so than the Herring Gulls – always fleeing before other larids when approached. Never observed consuming anything substantial, but seen picking at tide thrown by-catch on one occasion. Plumage deteriorated slightly throughout the summer (notably remiges), but unfortunately paid less and less attention to after June so specifics cannot be provided. However, it was still a strong flyer through 18 July. It was especially gratifying to see both this bird and the Brown Booby in the same field of view on 4 July.
Description:	Very large, white-headed gull with seemingly pure creamy-white plumage. A few smudgy pale brown markings on sides and belly, but head, mantle, wings (including wing coverts) and tail entirely white. Large, squarish head with flat crown and rather long, parallel-edged, bicolored bill with well-defined gonydeal angle. Black tip of bill is clearly separated from fleshy-pink base; black restricted to tip distally from nares and gonys- no dark markings basally or along cutting edge. Ivory on extreme tip of bill. Small, dark ‘beady’ eyes on large head. Prominent tertial step and short wing projection. Legs were pinkish. Dark brown eyes, fleshy-pink, black-tipped bill (w/ ivory on extreme tip), lack of any gray feathers on mantle, and worn, pointed primaries identify it as a first cycle (first-summer) gull.
Voice:	Voice not heard.
Similar species:	First cycle Iceland Gull ruled out by size and bulky proportions alone. Albinistic/leucistic/bleached Herring Gull eliminated by overall chunky, almost pot-bellied proportions; large, squarish head; long, parallel-sided bicolored bill w/ fleshy-pink base and blackish tip (distal to nares); small ‘beady’ eyes w/ brown irides; short wing projection; and nearly completely white plumage, including remiges and rectrices (unlike bleached Herring).
Photographs or tape recordings obtained?	Yes, digiscoped photos obtained by Justin Bosler on 29 May w/ 4 attached.
Previous experience with this species:	Observations of over two dozen first cycle individuals from mid-Atlantic, New England, and Atlantic Canada in winter. Also, more recently, a first cycle individual studied at Port Fourchon (Lafourche) on 5 Apr.
Identification aids:	None
This description is written from:	notes made during the observations and memory.
Are you positive of your identification? If not, explain:	Yes, 100% positive.
Reporter:	Justin Bosler
Date and time:	10 January 2009 8:00 PM CST