Warblers’ springtime return a high point
Few groups of birds excites birders as much as the warblers. Visually, it’s not hard to understand the allure. These small songbirds are often brightly colored, especially males in freshly molted plumage. The 36 species that breed or pass through Ohio each year collectively comprise a rainbow of colors. Shades of blue, green, yellow, orange and combinations thereof are all represented, in artfully designed feathered packages.
I am not immune to their charms, and was pleased to find a singing pine warbler on March 13 in Clear Creek Metro Park. The male was singing avidly, busily establishing his territory. Probably newly arrived, he was resplendent in bright golden-yellow feathering, punctuated by a pair of white wing bars.
Of our 23 breeding warbler species, the pine warbler is the first to return and set up operations. They don’t have too far to travel. Some particularly hardy individuals regularly overwinter in southern Ohio. And nearly the entire population (13 million range wide, about 3,300 in Ohio) winters in the United States, mostly in Gulf and lower Atlantic coastal states.
Not all warblers stay nearby
Most warblers are not as provincial as the pine warbler. The vast majority of species migrate to distant lands: the Caribbean, Mexico and Central America, and the most intrepid venture deep into South America.
Their seasonal disappearance is part of the appeal. We do not have the energetic sprites at our disposal yearround. Thus their vernal return is a heralded event on the birder’s calendar.
The pine warbler leads off the warbler parade, and is as much a harbinger of spring as any bird. By the time this column sees print, others will have returned. Louisiana waterthrushes will be staking claims along small streams with a loud ringing song.
Soon to follow will be black-and-white, black-throated green, and yellow-throated warblers,
and northern parula. By late April the floodgates will be open, and species diversity and overall numbers will increase markedly. The pinnacle of warbler migration is the first two weeks in May.
Warblers feast on a smorgasbord of insects
This warbler invasion evolved to capitalize on the seasonal bounty of insects and spiders at northern latitudes. Millions of warblers descend on U.S. and Canadian forests and other habitats to feast and raise young on a buffet of caterpillars, crickets, midges, true bugs and more. They perish by the billions, victims of this gaudily garbed feathered army.
Because native plants foster these insects, many warblers have become tightly wedded to certain plants or plant communities. None more so than the pine warbler. Well-named, it only occupies mature pines and in Ohio that includes four native species: pitch, shortleaf, Virginia, and white pines.
The bulk of a pine warbler's diet is moth caterpillars, especially those that specialize on pine feeding. Many of these caterpillars have evolved an eerie similarity to pine needles and are incredibly hard to spot. That probably explains the pine warbler's habit of slowly creeping through fascicles of needles. They're probably tough to see even for a sharp-eyed bird.
One of the best local warbler spots is the beautiful Clear Creek Metro Park, where I made the accompanying image. The 5,300-acre park is only a half-hour from Downtown Columbus. It hosts a variety of habitats, and at least 19 warbler species nest there. A visit is highly recommended.
Naturalist Jim Mccormac writes a column for The Dispatch on the first and third Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.