English and Scientific names:

Brown Booby  (Sula leucogaster)

Number of individuals: 

1 in juvenal plumage

Locality: LOUISIANA: 


Specific Locality:

Wine Island, Isles Dernieres barrier island chain (29.0955 N, -90. .6108 W)

Date(s) when observed:

4, 18 July 2008

Time(s) of day when observed:  

5:15-5:45 PM CDT on 4 July / 10:20-10:50 AM CDT on 18 July

Reporting observer and address:

Justin Bosler

Lancaster, PA

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


Edward J. Raynor

Other observers who independently identified the bird(s):


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

Excellent light conditions on both occasions with sun more or less directly overhead.

Optical equipment: 

Zeiss Victory FL 8x42 binocular (excellent) and Brunton Eterna angled 80mm spotting scope (good)

Distance to bird(s): 

Within 75 meters on 4 July and even closer, within 15 meters, on 18 July as it flew by at very close range between resting at various spots on the beach.

Duration of observation:

Approximately 30 minutes on both occasions.


Barrier island sandy beach at interface of large bay (Terrebonne) and Gulf of Mexico.

Behavior of bird: 

Resting and preening on 4 July and resting, preening, and flying on 18 July. 


Fairly large, dark sulid with entirely dark brown upperparts, head, neck, and upper breast.  Sharp demarcation between dark brown of head and neck and paler brown of breast and belly.  Whitish underwing coverts (wing linings) visible in flight, as well as wholly dark brown tail and uppertail coverts.  Facial skin, irides, and bill silvery-blue.  Legs and feet dull yellow.  Very agile and graceful flyer with long, narrow wings in combination with longish neck and caudal projection.


No voice heard.

Similar species:

Other sulid species eliminated by wholly dark body; whitish wing linings; silvery-blue facial skin, irides, and bill; and dull yellow legs and feet.

Photographs or tape recordings obtained?

Photographs obtained and attached by Justin Bosler.

Previous experience with this species: 

Limited to two prior observations: a juvenile in flight at South Padre Island, TX (Cameron) on 26 Nov 2005 and 2 adults and 1 juvenile in Florida Straights between Key West and Dry Tortugas, FL (Monroe) on 25 Aug 2006.

Identification aids:


This description is written from: 

notes made after the observation and memory.

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


Yes, 100% positive.


Justin Bosler   

Date and time: 

26 November 2008    12:30 AM EST