Hello Northern NV birders. Martin Meyers originally reported the bird in question, and it has had me stumped for quite some time. Nick Rosen gave a great description of the bird, and I immediately had a hunch. I sent word to Tristan McKee (formerly of the California Bird Records Committee) and his response is posted below. Lets go get some photos!!!
*quick ID tips.... short primaries, long legs, thick neck, darker than Thayer's. The Japanese gull site is a great reference for photos. http://www23.tok2.com/home/jgull/slayty.html
Reno Nevada 2/6/14
Begin forwarded message:
> From: Tristan McKee <[log in to unmask]>
> Subject: Slaty-backed Gull in Reno
> Date: February 6, 2014 3:06:38 PM PST
> To: Zachary Ormsby <[log in to unmask]>
> At Zachary Ormsby's request, I took another look at the interesting "large Thayer's-type" gull that has been frequenting Sparks Marina. I believe this is the same bird Martin Meyers photographed earlier this winter, and having spent the winter researching this topic, I think it can be identified as a Slaty-backed Gull. It was extremely dark when it showed up in fresh juvenal plumage, and this look is unfamiliar to North Americans but can be seen in many photos on the Japanese Gull-Site. The very short primaries of this bird are typical of Slaty-backed; note that the primaries are significantly shorter than the distance between the base of P10 and the bend in the wing. The bill structure looks perfect for a female Slaty-backed; people tend to hone in on only the males. We are having this problem with a very similar female in Arcata, CA:
> I am quite sure that this bird is too big and too dark for a Thayer's. There are a lot of other helpful features, which I will elaborate on later, but I wanted to get this out ASAP so that people might be able to see it today or tomorrow. More photos of the wing structure would be most helpful!
> Best of luck,
> Tristan McKee