Common NameThayer's Gull
Scientific NameLarus glaucoides thayeri
Type of ReportRare Species
Date of Observation12/23/2017
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Number Observed1
Reporting Observer's NameSpencer Hardy
Mailing Address133 Tucker Hill Rd
Norwich, VT 05055
United States
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EmailEmail hidden; Javascript is required.
Date Completed12/23/2017
Latitude of Observation (enter 0 if unable to provide)44.3111362
Longitude of Observation (enter 0 if unable to provide)-72.7148581
Place NameGrow Compost
TownshipMoretown
CountyWashington
Vermont eBird Checklist URLebird.org
Time of Day11:10 AM
Length of Time Observed10
Maximum Estimated Distance from Bird (in feet)250
Minimum Estimated Distance from Bird (in feet)200
Noteworthy Weather Conditions

Cold rain after 6-10" snow yesterday

Optical Equipment Used for Observation

Minox 8x42

Observer’s Previous Acquaintance With This or Similar Species

I have seen several Iceland Gulls and thousands of Herring Gulls, this is my first Thayer's. I have been looking closely at HEGU a lot in the past few weeks trying to find the GLGU that has been seen in Burlington

I certify that any attachments included with this report were captured during this observation event​​.
Description of Habitat

An active compost faculty in the woods along the Winooski river. This is a reliable place for large gulls during the winter. 17 HEGU, 6 GBBG, and 1 immature ICGU present during this observation. No RBGU seen.

Behaviors Observed

Only seen while perched on the top of the barn roof in a line with several adult Herring Gulls. Watched as it took off, then it was lost in the mix

Description of Vocalizations

None definitely coming from this bird

Verbal Narrative & Description of Observation

This guy struck me as different as soon as it landed, and I watched it on and off for 10 mins before it flew. While perched I could not see the wing tips or legs, though both were seen briefly as it took off.

Relative Size & Shape

Slightly smaller than nearby HEGU

Head

Head was more rounded than HEGU, reminding me of RBGU, or as I first was hoping Mew Gull. Head generally white, with fewer markings than nearby HEGU. The most apparent streaking was on the sides of the lower neck. The eye stuck out as different than that of the HEGU. It was smaller and appeared all dark, though a few times I thought I saw a slightly less than black tinge. At the distance of this observation, all the other HEGU (~5) nearby had big, bright yellow irises with visible red orbital rings.

Feet & Bill

Legs pink, bill yellow but noticeably smaller and more slender than HEGU. The red spot on the bill was present but much less obvious than on the HEGU.

Upper Back

Medium gray, similar to HEGU

Lower Back & Rump

Not seen

Wings

Medium gray with black tips, I didn't notice how extensive the black was, as the wing tips were only visible for a second in flight

Breast, Belly, Flanks, Under Tail Coverts

White

Tail

Not seen

IMPORTANT: What similar species were eliminated when making the identification and how was this bird different?

Nominate Iceland (and Kumlien's) Gulls would have pale wing tips and lighter backs. The vast majority of HEGU have pale eyes and the head and bill shape of this bird were what first attracted my attention in direct comparison to HEGU. Would be great if someone else can get photos of the wing tips/underside of the wings.

Other Notes & Comments

Adult.

This report was written from notes taken:Immediately After