Laura Erickson's For the Birds

Yellow-rumped Warblers and Palm Warblers

(Recording of a Palm Warbler)

Most of the warblers are gone from the northland till next spring–over 10,000 flew past the Lakewood Pumping Station on September 23rd, all headed south. There are a few warblers remaining, but they’re just about all yellow-rumps and palms.

Palm Warblers are the ones people see on rooftops and hopping on the grass in their backyards. They have the distinctive habit of slowly wagging their tails up and down, drawing attention to their lemon yellow undertail covert feathers. Covert feathers are so-named because they hide the bases and shafts of the larger flight feathers of the wings and tail–much like some government covert operations hide base motivations and may actually be giving us the shaft.

Palm Warblers nest on the ground in open tamarack-black spruce bogs, and so can be found all summer in parts of northern Minnesota. They’re abundant migrants in both Wisconsin and Minnesota, especially along Lakes Michigan and Superior. Fall migration begins in mid-August and lasts well into October–there was even a record in northern Minnesota one November 19.

As with most very late migrants, Palm Warblers don’t winter too far south of the border, and a great many spend the season vacationing in Florida, where they greet homesick Northlanders with a wag of their tails. They’re often called wagtail warblers or yellow tip-ups for this habit, and either nickname is probably more appropriate than their proper name, since most Palm Warblers spend very little of their lives in palms. The first specimen obtained by early ornithologists just happened to be shot from a palm tree on its West Indies wintering grounds, and the name stuck.

A famous ornithologist and warbler expert, Ludlow Griscom, once berated the palm warbler as dull and uninteresting, but I find watching this bird deeply satisfying. Whenever one hops up to me on my perch during dawn dickey duty at the Lakewood Pumping Station, it studies me for a moment or two, all the time wagging its tail, and then suddenly calls out “Tch!” like a disapproving schoolteacher, and lights out for the territory.

The other late season warbler is the yellow-rump– nicknamed the butterbutt in some places for its bright yellow rump. Remember–if the yellow is on the backside, it’s a yellow-rump, and if its on the underside, it’s a Palm Warbler. In fall the yellow rump is often the only distinctive marking on an otherwise drab bird, but a breeding male in spring is handsome, with his yellow cap, rump, and epaulets setting off a nice contrast to his black-and-white plumage.

The Yellow-rumped Warbler is the most abundant of all northern warblers. It breeds in coniferous foress throughout northern Minnesota and Wisconsin, though, oddly enough, the two most prominent ornithologists of an earlier era, John James Audubon and Alexander Wilson, never once located a nest of this species.

Yellow-rumps are abundant all winter in the southern U.S. and even further north–several have wintered in Wisconsin over the years, and there are records of at least four attempting to overwinter in Minnesota at feeding stations–at least two of these managed to survive the whole season.

As the tropical rain forest is steadily destroyed, many of our breeding warblers which winter down in Central and South America will become rare or even endangered. It’s at least some comfort to know that two of the friendliest warblers of all will be with us for a long time to come.

(Recording of a Yellow-rumped Warbler) This is Laura Erickson, and this program has been “For the Birds.”