Verification of Unusual Sight Record
For Utah

Rec. # 2011-13

Common name:

Lesser Black-backed Gull

Scientific name: Larus fuscus
Date: 18 February 2011
Time: 8:45-11:45 total
Length of time observed: varying. shortest 5 min, longest 30 minutes
Number: 4
Age: adult
Location: Farmington Bay WMA, Unit 1
County: [Davis]
Distance to bird: nearest bird about 150 feet. Farthest approximately 1000 feet.
Optical equipment: Swarovski 65mm, 25-45x eyepiece
Weather: high over cast
Light Conditions: fair to good
Description:        Size of bird: slightly larger than California Gull
(Description:)       Basic Shape: long winged, mid sized gull
(Description:)  Overall Pattern: blackish backed, otherwise white
(Description:)            Bill Type: medium bulk (similar to Herring but slimmer) gull bill
Field Marks and
Identifying Characteristics:
(Photos of #2011-13A) - (Photos of  #2011-13B) -
With photos was sent brief description [go through above links]
Each bird was noted to have a blackish (or, actually, black appearing) back with white body and head. Head had moderate streaking, mostly on crown and nape. Some dusky side chest streaking seen on closer birds. On all birds, pale eye and yellow legs noted. All birds were compared directly with nearby Cal Gulls and were substantially darker backed (each observed long enough to discern that this was not a trick of light, especially on more distant 2 birds, where eye color was harder to be certain of).
Song or call & method of delivery:  
Similar species and how
were they eliminated:
The back color combined with size and leg color (and eye color) eliminates all other similar gulls occurring in North America.
Previous experience with
this & similar species:
I have seen several hundred Lesser Black-backed Gulls in eastern USA (a few in western) and in Europe
References consulted: None
Description from: From memory
Observer: Steven Mlodinow
Observer's address: 1522 Venice Lane, Longmont, CO 80503
Observer's e-mail address:
Other observers who independently identified this bird:  
Date prepared: 25 Feb 2011
Additional material: Photos 2011-13A and Photos 2011-13B