By Bryan Stevens
I detected some signs of migration during a backyard lawn chair birding session on Thursday, Sept. 3. A croaking Great Blue Heron circling the property, the shrill cries of Cedar Waxwings, scolding vireos, and the intermittent buzz of hummingbird wings all contributed to the background noise.
The first warbler of the season, a quick blur of yellow and white, disappeared into the green and thus escaped identification. That’s the way of it: Sometimes, you identify the bird, but at other times it slips past without lingering enough for that moment of confidence. You have to love September, even if the birds are entirely ignorant of pages on a calendar. As summer wanes, the pace of migration has spiked. If that first warbler got away, I know others will follow behind it.
Some of them will have fanciful names like Blue-winged Warbler, Black-throated Blue Warbler, Blackburnian Warbler and American Redstart. Each of the warblers exists as a sort of magnet to induce me to keep binoculars always close at hand.
The 50 or so species of warblers that make their home in the eastern parts of the United States and Canada during the spring and summer months are now winging their way south. The Blackpoll Warbler, which holds the distinction for the longest migration of any species of New World warbler, will journey from the forests of Canada to spend the colder months in northern South America. Because of a peculiarity of this bird’s fall migratory habits, birders in Northeast Tennessee are far more likely to see this late-arriving warbler in May than in the autumn.
A few warblers — Pine Warbler, Magnolia Warbler and Palm Warbler — are named for trees for the simple reason that their European discoverers happened to first observe them in the branches of their namesake trees.
For most of these warblers named to honor various trees, their common names are, at best, a misnomer. Throughout most of its life, the palm warbler doesn’t even encounter palm trees. Johann Friedrich Gmelin, a German naturalist who lived from 1748 to 1804, saddled the palm warbler with its inappropriate name. Gmelin based his naming of the bird on the fact that a specimen had been collected on Hispaniola, an island in the Caribbean with an abundance of palm trees.
Gmelin published several textbooks in the fields of chemistry, pharmaceutical science, mineralogy, and botany. He also had a hand in publishing a catalog of scientific names for various species, including some birds that had until that point never been given a species classification. Thanks to his efforts, the palm warbler has forever been linked with a type of tree that is, at best, entirely incidental to the bird’s life cycle.
The same is true for the Magnolia Warbler, which would have been more suitably named the Spruce or Fir Warbler, as the species is highly dependent on northern coniferous forests as nesting habitat. The Pine Warbler, at least, restores credibility to some of the early experts who have given these tiny birds their common names. The Pine Warbler does indeed prefer stands of pine trees, showing particular favor for pitch pines.
These three “tree warblers” are all fairly common fall migrants, making stops in gardens, backyards and woodland edges throughout Northeast Tennessee, southwest Virginia, and western North Carolina. They and their relatives will make the remaining weeks of September and early October an exciting time for warbler enthusiasts.