Verification of Unusual
Sight Record
For Utah
Rec. # 2011-69
| Common name: |
Western Gull |
| Scientific name: | Larus occidentalis |
| Date: | 12-28-2011 |
| Time: | 11:00AM |
| Length of time observed: | 30 minutes |
| Number: | 1 |
| Age: | 3rd winter |
| Sex: | ? |
| Location: | Farmington Bay |
| County: | Davis |
| Latilong: | |
| Elevation: | 4,200 |
| Distance to bird: | 50 yards |
| Optical equipment: | 20-60X Alpen spotting scope,10X50 Brushnell binoculars,Canon SX20is digital camera |
| Weather: | overcast |
| Light Conditions: | no direct sunlight,which would have mad everything backlite, but not a ton of light |
| Description: Size of bird: | Large gull |
| (Description:) Basic Shape: | gull like |
| (Description:) Overall Pattern: | pale head and breast,with a very dark mantle |
| (Description:) Bill Type: | huge spade shaped bill |
|
(Description:)
Field Marks and Identifying Characteristics: |
This bird stood out prominently among the pale backed Heering, California,
Ring-billed and Thayer's Gulls with its large size, dark charcoal gray mantle
and very pale head with a huge bill. It was very close and tame and we watched
it for nearly half an hour as it fed on dead fish (see photos) |
| Song or call & method of delivery: | no heard |
| Behavior: | Feeding on dead fish on the ice bank with shallow open water nearby. A couple times it spoked and flew around, but landed back in the same spot. |
| Habitat: | frozen over fresh water pond in a large marsh on the eastern edge of the great salt lake |
| Similar
species and
how were they eliminated: |
Only other dark mantled gull likely in Utah is a Lesser-black Backed Gull, which was also present giving direct comparisons, most notably the dirty brownish head and smaller size. Great Black-backed Gull should have a different shaped bill, and there are no Utah records I am aware. |
| Previous
experience with this & similar species: |
Yes. I saw the 2nd winter bird at Farmington bay last february.also I saw an adult Western Gull at Farmington bay in february of 2009 |
| References consulted: | Sibley guide to Birds 2000 |
| Description from: | From memory |
| Observer: | Bryant Olsen |
| Observer's address: | 688 East 700 South SLC,UT 84102 |
| Observer's e-mail address: | bryant_olsen@yahoo.com |
| Other observers who independently identified this bird: |
Norman Jensen,Gail Jensen,Mark Jensen,Ned Bixler,Tanner Poe, Jerry Poe,Mark
Thai,Karen Kirchhoff,others |
| Date prepared: | 12-29-2011 |
| Additional material: | Photos |
| Additional_Comments: | There has been some suggestion,by Tim Avery, that this gull may have some introgression of Glaucous-winged Gull, based on some brown markings on the nape. I am no expert on gull hybrids,but this was a very dark mantled bird,and if some hybridisation was involved,it is not a first generation hybrid,or an "Olympic Gull". I will let the committee decide on the exact ancestry of this bird,based on the photos submitted,as it is beyond me,but no doubt it has mostly Western Gull linage. |