By Bryan Stevens
Do you like to have a morning cup of coffee as you watch the early-bird arrivals at your backyard feeders? If so, you may want to thank some of the warblers and other neotropical migrants that consume tiny insect pests injurious to coffee farms.
The website Coffeehabitat.com provides an archive of interesting reading material about the connections between coffee farming and many neotropical birds. According to a profile on the black-throated blue warbler at the website, this particular warbler has a strong affinity for wintering on coffee farms.
The black-throated blue warbler is a nesting bird in hardwood and mixed forests in many mountainous regions of eastern Tennessee, southwestern Virginia and western North Carolina. In fact, the species nests as far south as northern Georgia along the Appalachian Mountains. Those birds not nesting in the Appalachians make their summer home in southern Canada, as well as northern states like New York and Pennsylvania.
Thanks to scientific tests of the birds’ feathers, scientists now know that most of the black-throated blue warblers that spend the summer nesting season in the Appalachians are in turn wintering in Puerto Rico and Hispaniola. The black-throated blue warblers from the northern part of the range for the species spend the winter months in Cuba and Jamaica.
I’ve been spending more time than usual in my yard since the arrival of September, and I’ve been rewarded with glimpses of numerous migrating warblers, including Tennessee warbler, Blackburnian warbler, Cape May warbler, black-and-white warbler, chestnut-sided warbler, hooded warbler, Northern waterthrush and black-throated green warbler, as well as a dazzling male black-throated blue warbler.
If you recall the 1980s hit song, “Sharp Dressed Man,” by ZZ Top, perhaps I can give an accurate impression of the male black-throated blue warbler. He a dapper, sprightly fellow with a blue topcoat that dominates first impressions. It’s only after seeing the shock of blue that the observer takes notice of the black throat and the black feathers forming a dark facial mask, as well as a clean divide between the bird’s blue crown and back and the clean white underparts. The male even carries a fresh pocket “handkerchief” in the form of a white block on each wing. This becomes a diagnostic mark in the female’s less impressive version.
The sexes of black-throated blue warbler are the most markedly different among all the warblers. Even the famous early naturalist and painter John James Audubon got confused by the black-throated blue warbler male and female. He even made the mistake of painting a young black-throated blue warbler and misidentifying it as “pine swamp warbler.” The female black-throated blue has nary a trace of black in her feathers. Her plumage is mainly a dull olive-gray with dingy white underparts. Her only tie to her mate when it comes to appearance is her much more modest version of the “pocket handkerchief” on each wing.
In Jamaica, black-throated blue warblers are identified by Coffeehabitat.com as the number one predator of the dreaded coffee berry borer. So, as you raise that cup of affordable morning coffee, thank the black-throated blue warbler for eating all of those harmful pests that, left unchecked, would cause coffee prices to spike.
Bryan Stevens lives near Roan Mountain, Tennessee. To learn more about birds and other topics from the natural world, friend Stevens on Facebook at https://www.facebook.com/ahoodedwarbler. He is always posting about local birds, wildlife, flowers, insects and much more.
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