Earth Almanac: November/December 2007

Screamin’ Jay Squawkings

So adept are blue jays at making their presence known throughout their range (basically the eastern two-thirds of our nation and much of southern Canada) that few people realize they migrate. Mostly it’s the young ones, filtering down from the north in small groups that rarely exceed 50 individuals. Now they’re uncharacteristically quiet. This silence, however, is more than offset by the birds that remain. Early 20th-century ornithologist Edward Forbush described blue jay behavior as mainly “fuss and feathers—bluff and bluster” and noted: “Where there are blue jays, there is action and usually noise, for jays, like crows, are fond of hearing their own voices. Often a great uproar in the woods may be traced to a dozen or more blue jays in the tree-tops, screaming as if in great terror or pain, and apparently for no earthly reason except to keep up the excitement.” But in winter, as in all seasons, jays are also capable of soft, sweet song, and because so much of it is exquisitely accurate mimicry of other birds, they are seldom given credit for it.

Vegetarian Mermaids

When the first line storms of autumn chill the waters of the Atlantic Ocean and Gulf of Mexico, Florida manatees (a hardy race of West Indian manatee) ease toward Florida from as far west as Texas and as far north as Virginia. The West Indian manatee, the dugong, and the Amazonian and West African manatees are the only herbivorous marine mammals on the planet. They comprise the order Sirenia, named for the Sirens of Greek myth because early seafarers were said to have mistaken them for such. Hard up indeed was the sailor who perceived a mermaid in the form of one of these obese, bewhiskered, wrinkled, squinty-eyed, distant relatives of the elephant. Lacking the thick blubber of other marine mammals, Florida manatees must spend the winter in warm springwater or the heated discharges of power plants. They are equipped to survive in either freshwater or saltwater, but in salt they need sources of freshwater for drinking. Strikes by motorboats are one of the leading causes of mortality for these highly endangered mammals, and when they congregate in Florida waterways, wildlife managers further restrict boat speeds.

Winter’s Good Cheer

In nature one species’ Aspen may be another’s Miami Beach. Consider, for example, snow buntings. When winter kills insects and vegetation in their summer range these robust sparrows migrate to the relatively warm, distant south, which for them is the icy, snow-blasted open country of southern Canada, the northern United States, and corresponding latitudes in Asia and Europe. Look for them as they swirl down into fields and meadows, flashing white as they turn their bellies and underwings toward you in unison, then vanishing as their black-tipped wings and brown backs merge with the dark winter sky. A sudden cold snap can send enormous flocks south. Even on the coldest winter days, snow buntings keep up a cheerful-sounding commentary of brisk, musical call notes. Nineteenth- and early 20th-century naturalist John Burroughs compared this vocalization to the “laughter of children.”  “The fox hunter,” he wrote, “hears it in the snowy hills; the school boy hears it as he breaks through the drifts on his way to school; it is the voice of good cheer and contentment.”