Spring migration is finally in full swing. The forest canopy is greening up and the insects are hatching just in time for the migrants moving through. Our birds fall into three (very) general groups: the skeleton crew that is here all year long like cardinals, chickadees, and the like; the species that everyone thinks migrates but just shift their range up and down the continent, like robins; and the real deal, what ecologists call "neotropical migrants" like most of the warblers, tanagers, and orioles. These birds are really Central and South American; they just come up here when the sunlight goes over twelve hours per day. To them, it's an endless summer here, full of tasty bugs with lots of time to pursue them.
That explains the why. The how is pretty much anybody's guess. These are not big birds like Canada geese or whooping cranes who learn migration from their elders. Warblers are birds that can fit in a film canister. They fly thousands of miles, mostly at night (days are for feeding and resting), without maps, GPS, or asking for directions. There is good evidence that at least some species have a sky chart imprinted in their brains; others probably use the Earth's magnetic fields; most probably use a combination of both. Most of them come back to the same patch of forest or tundra where they were hatched.
Some nest here, others, like solitary sandpipers, are just passing through on their trip from Argentina and Uruguay to the Boreal forest or tiaga which encircles the globe at the higher latitudes.
Neotropical migrants are borrowed birds; escaping their tropical habitats which are jam-packed with other species in order to get some elbow room to produce young up here. Most of them look like they belong in the rain forest; indigo buntings are flying chunks of sky that put bluebirds to shame.
Neotropical migrants are borrowed birds; escaping their tropical habitats which are jam-packed with other species in order to get some elbow room to produce young up here. Most of them look like they belong in the rain forest; indigo buntings are flying chunks of sky that put bluebirds to shame.
Prothonotary warblers, up from the Yucatan and northern South America nest in this area. They are one of the few warbler species that nest in cavities, usually in swamps. The chicks can swim. This bird gets its name from the color of the vestments of the Vatican College of Prothonotaries, part of the Curia. I have always thought it one of the more poetic common names for any animal. Sure beats the hell out of yellow-rumped warbler (known to birders as "butter butts").
Spring is in full cry. Our (really their) migrants are coming up, already here and moving on, or already here and nesting. The blue-gray gnatcatche
r (another cool name; workman-like but falling trippingly off the tongue) from the Caribbean and Central America is already brooding eggs. I found this pair, the hen on the nest, and the male feeding her tent caterpillars. The nest is made from lichens and caterpillar silk; the silk gives it flexibility, allowing for expansion as the chicks grow.
r (another cool name; workman-like but falling trippingly off the tongue) from the Caribbean and Central America is already brooding eggs. I found this pair, the hen on the nest, and the male feeding her tent caterpillars. The nest is made from lichens and caterpillar silk; the silk gives it flexibility, allowing for expansion as the chicks grow. The chicks will be up and out of the nest by mid-June, just in time for mom and dad to start a second brood. No empty nesters for this species - just crank 'em out and kick 'em out. Don't worry about tuition either.
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