Hunterdon County Thayer's Gull

On March 30, Frank Sencher Jr. sent out a text that he had a probable Thayer's Gull at Spruce Run.  I took a quick break from my Backyard Big Year and was the first additional birder on the scene.  Frank quickly got the bird in my scope and sure enough it looked really good for an adult Thayer's Gull--a bird reported but never confirmed with photos for the county.  So I got out my iPhone 6 and trusty PhoneSkope adapter and started shooting video of the bird.

In these stills you can see the dark eye, bright raspberry pink legs, roundish head, smallish greenish bill, and most importantly the wing pattern--mostly white primaries underneath with small dark tips, and much reduced black on wingtips--mostly just tips and leading edges to the primaries.

Several other birders were able to get to the bird over the next few hours, and it was relocated again on the afternoon of March 31.  There are over 2000 gulls in the area (I counted over 2400 streaming by from my yard this morning), so hopefully it will stay around for a few more days and return in the evenings for more to enjoy.

Underwing with narrowly dark-tipped white primaries.  And doing the Can Can with those amazing raspberry pink feet.

Crucial shot of underwing, note white primaries with dark tips.

Dark eye, rounded head in this profile shot, and smallish greenish bill are all consistent with Thayer's Gull.

This shot makes the bill look heavier, but note the pale reddish gonydal spot, dark eye, and the mostly white primaries with dark tips.  And you gotta love the bright raspberry colored legs and feet.

In this side view the primaries are clearly dark above with large white spots, and the underside of the primaries (on the folded hind wing) is mostly white with a small dark primary tip visible.  Also note greenish small bill with a faint reddish-orange gonydal spot on lower mandible.  

This is a crucial shot of the upper wing pattern--note the reduced black mostly on the tips and leading edge of the primaries.  Also dark iris and bill without much patterning.

Sitting in front of a Herring Gull, unfortunately this view doesn't allow a good comparison of size differences, but the bird consistently looked a bit smaller than a Herring Gull.  Here you can see the brown streaking on the head and dark eye.  And brighter pink legs than the Herring Gull behind it.

In this shot you can see a better size comparison with the adjacent Lesser Black-backed Gull.  Also note smallish bill with small reddish gonydal spot on lower mandible.  And those bright pink legs are pretty obvious!