My best Thayer's gull memory — I'll bet you don't have one of those — is from a day in Grand Marais, down by the harbor. Two knowledgeable birders were debating about a gull sitting with hundreds of other gulls on the breakwater.
Was the gull in question a Thayer's gull or perhaps a herring gull? Or an Iceland gull? The telling points of identification are subtle.
Slightly smaller bill, slightly smaller body, slight plumage differences, and a dark iris. Herring or Iceland gulls, for instance, have light irises. You wanted to look this gull right in the eye.
I don't remember the question being resolved. I probably wandered away.
The question, asked by many birders over the years, might become moot. Thayer's gull could become kaput. Maybe.
No, not an environmental catastrophe. It is a proposal to be voted on by the American Ornithological Society's North and Middle American Classification Committee. There is such a thing, and in the biological world it is important.
Because a Thayer's gull very closely resembles both herring and Iceland gulls, it could be lumped, becoming one with the Iceland gull.
There have been no genetic studies. That probably would be definitive. I would guess that no Ph.D. candidate has ever chosen this question as a thesis topic. We are left with arguing.
Dividing categories
This would be bad news for birders who keep life lists, records of birds seen. The check mark for Thayer's would have to be erased. When I think of the effort that can be devoted to seeing a Thayer's gull for certain, that seems unfair.
However, there is good news from the same table of experts. The Nashville warbler, brown creeper and Bell's vireo might be split. That means that one bird species becomes two (sometimes more than two).
If this happens, and if you have seen one of these new birds in its defined range, you could count it, retroactively — check, check, check. Range, where the bird is found, is very important. Along with genetics, appearance and song, it's used by the committee to consider yea or nay.
Birders will wish they kept more complete notes about where they saw Nashville warblers.
If I need such information I contact a friend in Canada with whom I have done much birding. He keeps excellent notes. He can tell me exactly when and where we saw this or that. And the weather, and who was with us, and maybe name the crummy motel where we stayed.
Splittsville for creepers?
Let's look at the brown creeper, a favorite of mine. It is the small brown bird we see here, mostly in winter, that circles trees trunks, always upward. It pokes behind layers of bark to nab insects.
There are two groups of brown creepers, northern and southern, and more than a dozen named subspecies. The differences under discussion include geography, forest type and plumage.
It the split happens, the names suggested are Nearctic and Neotropical, committee names for sure. Audubon gave birds the names of friends, Baird's sandpiper, for example, honoring another famous ornithologist.
I will always know our creeper as the brown creeper.
And if subspecies, important to science, ever become important to recreational birding, I will take up butterflies.
Read Jim Williams' birding blog at startribune.com/wingnut.
