English and Scientific names:

California Gull (Larus californicus albertaensis)

Number of individuals: 

1 third-cycle/basic ad. in prebasic molt (presumed male on basis of size)

 

Locality: LOUISIANA: 

Cameron Parish

Specific Locality:

Broussard Beach, ca. 2 mi. SE of Cameron

Date(s) when observed:

23 October 2010

Time(s) of day when observed:  

~4:45 – 5:00 PM CDT

Reporting observer and address:

Devin Bosler

Lancaster, PA 17601

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

No

Other observers who independently identified the bird(s)

No

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

Clear sky with optimal late afternoon sunlight.  Sun lowering on western horizon behind observer.  Backlighting or glare not a factor.

Optical equipment: 

Zeiss Victory FL 8x42, Kowa TSN 881 Angled 88mm scope w/ 20-60x optical zoom , Canon Powershot SD1100 IS (all equipment in excellent condition)

Distance to bird(s): 

ca. 100-125 meters

Duration of observation:

~15 min.

Habitat: 

Open beach on Gulf of Mexico.

Behavior of bird: 

Resting and preening on beach and in surf amid a very large group of larids.  As usual with majority of large gulls, it was exceedingly wary and did not allow close approach.  Not observed in flight.

 

Description:

A medium-large white-headed gull with medium gray mantle.  Decidedly long-billed and long-winged.  Fairly distinct white apical spots visible on folded wing (mirrors on P9-10).  Large mirror on P10 (no white edge on primary tips).  Some retained second generation upperwing coverts suggestive of third cycle.  Crown and nape lightly streaked, but otherwise clean white forehead, throat and breast.  Some diffuse smudgy markings on face.  Bright yellow, longish, parallel-sided bill with minimal gonydeal angle.  Conspicuous black and red markings on gonys.  Black smudge on distal portion of upper mandible above gonys, thus not definitive basic.  Dark brown irides.  Dull grayish legs and feet.  Larger build, paler gray mantle (shade darker than AMHE), and larger white mirror on P10 suggestive of interior-breeding (n. Great Plains) albertaensis.  This ssp. is the expected vagrant in LA.

Voice:

Silent.

Similar species:

Noticeably smaller, more round-headed than American Herring Gull (AMHG) and considerably larger than Ring-billed Gull (RBGU).  Medium gray mantle only slightly darker than AMHE and RBGU.  Relatively long, bright yellow bill w/ red and black gonys markings diagnostic of CAGU (lacking on AMHE and RBGU).  Dark brown iris and pale grayish legs are inconsistent with AMHE and RBGU at this age.  No other similar gulls.

Photographs or tape recordings obtained?

Digiscoped photographs by Devin Bosler.  Yes, attached.

Previous experience with this species: 

Prior experience from several western states.  On a few trips to the west coast, I have observed hundreds from WA south to CA.  Also inland at ID, MT and NM.  One previous encounter in LA (Broussard Beach, Cameron Parish on 1 Nov 2008).

 

Identification aids:

National Geographic Complete Birds of N.A. (Alderfer et al. 2005), 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

Date and time: 

27 October 2010  Time:  10:30 PM CST