English and Scientific names:

Glaucous Gull (Larus hyperboreus)

Number of individuals: 

One worn/bleached first-cycle

Locality: LOUISIANA: 

Jefferson Parish  

Specific Locality:

beach off LA-1 behind Blue Dolphin Inn, Grand Isle on 4/18, beach off LA-1 behind Artie’s Sports Bar, Grand Isle on 4/19 (ca. 1.5 mi. E of original location)

Date(s) when observed:

18, 19 April 2009

Time(s) of day when observed:  

~4:30-5:00 PM CDT on 4/18, ~2:45-3:00 PM CDT on 4/19

Reporting observer and address:

Devin Bosler

Baton Rouge, LA

Other observers accompanying reporter who also identified the bird(s):

Jeff Webster (found earlier) and E.J. Raynor

Other observers who independently identified the bird(s)

David Muth, Philip Wallace, Dan Purrington, Steve Cardiff, Donna Dittman, m. ob.

Light conditions (position of bird in relation to shade and to direction and amount of light):

Overcast sky on 4/18 with sufficient afternoon lighting.  Clear sky on 4/19 with optimal midday sunlight.  Sun angle high.  Backlighting or glare not a problem.

Optical equipment: 

Zeiss Victory FL 8x42, Nikon Fieldscope w/ 20-60x optical zoom, Canon Powershot SD 1100 IS (equipment in good condition)

Distance to bird(s): 

ca. 20-25 meters

Duration of observation:

~30 min. on 4/18, ~15 min. on 4/19


Sandy beach on Gulf of Mexico.

Behavior of bird: 

The gull was observed preening, flying, and at rest.  It was roosting with two first-cycle American Herring Gulls during both encounters.


A large, almost entirely white gull.  Gradual sloping forehead and flat crowned.  Brown smudges on breast, sides, and undertail coverts, but otherwise clean white plumage.  Relatively short wingtip projection and entirely white primaries.  Long and stout, parallel-sided bill with moderate gonydeal expansion.  Flesh bill with sharply demarcated black distal third.  Small, dark eye isolated on pure white head, giving beady eye appearance.  Flesh-pink legs and feet.



Similar species:

No other similar larids.  Its entirely white plumage is unique among first-cycle large gulls in N.A.  About the same size as surrounding Am. Herring Gulls, definitely not larger.  Leucistic or albinistic gulls can be ruled out by structure and bill color.   

Photographs or tape recordings obtained?

Yes, digiscoped photos by Devin Bosler.  Yes, attached.

Previous experience with this species: 

Very familiar with GLGU.  Previous experience from many encounters in PA, NY, MA, and two prior LA observations.  Most recent GLGU studied and photographed at Holly Beach (Cameron Parish) on 28 Mar 2009.

Identification aids:

National Geographic Complete Birds of N.A. (Alderfer et al. 2005) and Gulls of the Americas (Howell and Dunn 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, positive.


Devin Bosler 

Date and time: 

24 April 2009 

7:30 PM CDT