Jan 2, 2008

Lifebird #32 - A “Butter Butt?”

Old-pro birders like to call Yellow-rumped Warblers “butter butts.” I don’t think this originated with Pete Dunne—it does sound like him—I would guess it predates him considerably. The bright yellow spot on the rump of a brightly-colored breeding male in spring is quite evocative. I certainly am reminded of a pad of butter when I see it. One of the images below captures it well.

This was my first warbler, and I found it in my yard: I thought I’d hit the jackpot! Now I know that these are the generalists of the new world warblers, feeding on seeds and berries as well as insects. This versatility allows them to arrive in our area earlier than warblers who are strictly insectivores. In fact, by May 6th of a typical year these birds have been in our area for at least a month. They are common here, and are one of four or five warbler species that breed in large numbers in the Twin Cities area. The fact that I saw my first one in our yard is a testament to the fact that I was not really looking for them anywhere else.

The male Yellow-rumped Warbler seen above is perched on some brush near the shoreline of one of the ponds at Gervais Mill Park. It and others below are all examples of the “myrtle” subspecies that dominates east of the Rockies in North America. West of the Rockies, the “Audubon” subspecies is the usual bird, which is why my dad—who lives and birds in California—can be counted on to exclaim excitedly, “it’s a myrtle!” almost every time he sees a Yellow-rumped Warbler while visiting us in Minnesota.