Hello, Birders. Well! Nick Komar recently reported some interesting birds at Lake Loveland, Larimer County!
But take note of Nick's cautious language. The birds were "mystery gulls." Although Nick attached exciting names (Nelson's, Vega, Western) to those mystery gulls, he also said that those designations were merely "possible." As a general rule of thumb, any and all mysterious "large, white-headed gulls" should be assumed to be Herring Gulls. Even within a population, Herring Gulls are extremely variable. And when we get into variation *among* populations, the situation gets much hairier. (On several occasions in Colorado, I've seen what I think were Herring Gulls from eastern North America, and they really stood out.) David Sibley offers some important cautions in The Sibley Guide: "Variation in [Herring Gull's] size, structure, and plumage can create confusion with almost ever other large gull species." "First-winter birds are extremely variable; no two are alike." I think that last point is essential. No two are alike! Thus, if Bird A is a Herring Gull, and Bird B does NOT look like Bird A, then that does NOT mean Bird B is some other species. Bird B is still probably "just" a Herring Gull. Oh. That reminds me of something. Steve Howell has a great article on this very problem. The title of his article is--wait for it--"Could It Be 'Just' a Herring Gull?" Steve's article appears in the November/December 2005 issue of Birding magazine: http://aba.org/birding/v37n6p565.pdf Ted Floyd [email protected] Lafayette, Boulder County, Colorado -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
