It wasn’t until the late 1970s that my wife, Elizabeth, and I first started birding in a systematic fashion. That is, we began learning to distinguish species by their calls and songs as well as by their distinctive markings. For a while, it seemed to be an almost impossible task.
Little by little, however, we began to sort out the easier visual and auditory cues. We already knew some of the more common resident birds — cardinals, tufted titmice, pileated woodpeckers, robins, blue jays, white-breasted nuthatches, song sparrows, phoebes, etc. — by sight and sound. To these we quickly added indigo buntings, Arcadian flycatchers, blue-gray gnatcatchers, red-eyed and white-eyed vireos, rose-breasted grosbeaks, and other distinctive species that migrate north from the Gulf Coast or Central and South America into the southern Appalachians to breed.
After several seasons, we’d reached the point where we felt comfortable with identifying most of the species that appear in Western North Carolina on a permanent, summer breeding, or winter resident basis, as well as (to a lesser extent) those that only migrate through in the spring and fall.
But well into the 1980s, we remained somewhat intimidated by the wood warblers. To be truthful, we still have problems with warbler identification during the fall season when almost all of them have ceased singing and have assumed similar drab colorations.
Thirty-seven of the 40 or so warbler species listed in the field guide for the eastern United States have been reported from our region; and, of these, more than 30 can be expected on a regular basis.
Warblers are often described as “the butterflies of the bird world.” They don’t hold still. All you usually get is a fleeting second to try to catch their vocalizations and markings before they’re long gone. And they’re all pretty much the same size with songs and field marks that can be similar.
The first warbler we got a firm handle on was the yellow-rumped. One December morning we spotted a flock of them feeding in the river birches that line the Tuckasegee River here in Bryson City. We knew they were warblers. And we knew that only a few warbler species over-winter in WNC. And then — bingo! — we spotted their bright yellow rumps.
Few warblers winter in the Smokies region. The yellow-rumped is by far the most common one that does so.
Formerly considered two species — the myrtle warbler in the East (which displays a white throat) and the Audubon’s warbler in West (which displays a yellow throat) — the yellow-rumped warbler was reclassified as a single species when it was established that the myrtle and Audubon’s sub-types hybridized where their ranges overlap. It is one of the most common warblers in all of North America, with a breeding range that extends from Alaska south to Guatemala and east to the northeastern United States.
As might be anticipated, this species is one of the most ecologically generalized. Individuals forage in a broad range of microhabitats and employ a variety of foraging techniques, from fly-catching to foliage-gleaning for insects. During the winter, it can be observed in almost any habitat, expanding its diet to include a substantial amount of fruit. Its ability to digest the waxes in bayberries allows some yellow-rumped populations to winter in coastal areas as far north as Nova Scotia.
The designation “yellow-rumped” is apt because this warbler displays that signature rump color even in non-breeding plumage.
Back in the early 1990s, I was birding with ornithologist Paul Kerlinger on Horn Island in the Gulf Islands off the Mississippi coast. Scanning some nearby shrubs through his binoculars, Paul sighed and said, ‘It’s just another damned ‘butter-butt.’”
Not knowing what he was talking about I took a look through my binoculars. It was a yellow-rumped warbler. Paul’s description was perfect.
See for yourself. The “butter-butts” are just now arriving back in the Smokies region from their northern breeding grounds.