English and Scientific names:

Glaucous Gull (Larus hyperboreus)

Number of individuals: 

1 worn first cycle

Locality: LOUISIANA: 

Fourchon Beach at mouth of Belle Pass, Port Fourchon

Specific Locality:

Lafourche

Date(s) when observed:

5 April 2008

Time(s) of day when observed:  

8:30-9:45 AM CDT

Reporting observer and address:

Justin Bosler

 Baton Rouge, LA

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

 

Devin Bosler

Other observers who independently identified the bird(s):

Marty Guidry and Dan Purrington

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

Good light conditions with overcast skies.

Optical equipment: 

Zeiss Victory FL 8x42 binocular (good condition) and Nikon Fieldscope 60ED w/ 45x optical zoom (fair condition)

Distance to bird(s): 

Within 75 meters

Duration of observation:

Most of an hour and 15 minutes

Habitat: 

Beach between tide line and wrack line, and on shell spoil at mouth of Belle Pass

Behavior of bird: 

First observed picking through wrack line on the beach very near the mouth of the pass with 6 first cycle Am. Herring Gulls.  It continued to walk around on the beach as we approached from a distance.  It was resting/preening when it was spooked from the beach with the other gulls.  All of the gulls, including the Glaucous, relocated to a shell spoil on the E side of the pass.  Once there, it continued to preen intermittently as it stood slightly apart from the mixed-species flock of waterbirds.  

Description:

Very large, white-headed gull with seemingly pure creamy-white plumage.  A few brownish markings on hind neck, mantle, sides, and belly, but 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 pinkish-flesh 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 fleshy-pink.  Dark eyes,  pinkish-flesh, black-tipped bill, lack of any gray feathers on mantle, and worn, pointed primaries identify it as a first cycle (first-winter) gull. 

Voice:

No voice heard

Similar species:

Bleached/worn first cycle Am. Herring Gull eliminated by larger size, pure creamy-white plumage, wing-tip paler than upperparts, diagnostic bicolored bill with black tip clearly separated from pinkish-flesh base distally from nares, dark ‘beady’ eyes, and short wing projection.  Pale first cycle Iceland Gull eliminated by large size, diagnostic bicolored bill, dark ‘beady’ eyes, squarish head with flat crown, and short wing projection.  Pale first cycle Thayer’s Gull eliminated by aforementioned characters that eliminate Iceland plus wing-tip paler than upperparts. 

Photographs or tape recordings obtained?

Single digiscoped photograph obtained by Justin Bosler.  Yes, attached.  Additional in flight images by Devin Bosler at (http://picasaweb.google.com/DevinBosler/

GlaucousGullLarusHyperboreusHyperboreus)

Previous experience with this species: 

Observations of over two dozen first cycle individuals from mid-Atlantic, New England, and Atlantic Canada in winters of 2003-2008.

Identification aids:

  1. at time of observation:  None
  2. after observation:  Gulls of North America, Europe, and Asia (Olsen and Larsson, 2004)

This description is written from: 

This description is written from notes made during the observation and from memory.

Are you positive of your identification? If not, explain: 

 

Yes, 100% positive

Reporter: 

Justin Bosler   

Date and time: 

22 April 2008    8:50 PM