Earth Almanac: January/February 2001

They look like rats, only bigger, fatter, toothier, and slower. Opossums invaded North America from the south about the same time Caucasians invaded it from the east, and both invasions are still in progress. Because opossums evolved in a mild climate, the ones waddling through your headlight beams in the snowbelt from Yankeeland to Colorado are apt to have frost-pruned ears and tails. The loss of ear tissue only makes the beasts look uglier (if possible), but because they store a lot of fat in their tails, the abbreviation of those appendages may curtail their northward expansion. The opossum is the continent's only marsupial. Females deliver bee-size young after only twelve and a half days of gestation. Newborns, essentially mobile embryos, haul themselves up into a kangaroo-style pouch, where they either die or find a nipple that expands in their mouths, buttoning them into place. In one study, a researcher could fit only 21 beans into the brainpan of an opossum skull but needed 150 to fill the brainpan of a raccoon. The opossum's remarkable success proves what countless mid- and low-level business managers already know--that intelligence is no criterion for advancement.

Mighty Ducks

Long after other wildfowl have fled south--when frozen kelp crunches under your boots and spindrift glazes rocky headlands--our fastest, whitest sea duck finds winter refuge along the Atlantic and Pacific seaboards or on large, open lakes. Oldsquaws (so named because they talk so much and so loudly, but now being called long-tailed ducks by the politically correct) sound like a pack of hounds dancing around a treed bear.

In fact, the species' Latin name, Clangula hyemalis, means "noisy winter duck." Now the drakes--with the long, sharp tails--are starting their courtship displays, which include porpoising, head shaking, bill tossing, bill dipping, wing flapping, and neck stretching. Several drakes may circle a hen, gurgling, gabbling, and shouting ah, ah, ah or ow-owly, owly, owly. Oldsquaws can dive to 200 feet, deeper than any other duck, and they fly like hurricane-borne shingles. Hunters who have shot oldsquaws as they veered and twisted directly overhead have found pellet holes in their backs.

Winter's Candy

Sapsicles--those shards of frozen sap that hang from broken branches of hardwoods--seem made for consumption by kids and adults with kids' hearts. If you close your eyes and concentrate, you can taste the coming spring. Sapsicles are sweeter than liquid sap because the sugar has been concentrated by evaporation. Look for them on warm, late-winter days after night temperatures have dipped below freezing. According to some connoisseurs, black-birch sapsicles have a faint wintergreen flavor; butternut sapsicles are vaguely reminiscent of cider. While red maple and box elder sapsicles are superb, the best are produced by sugar maples, which grow from Canada to northern Georgia to eastern Kansas. Some of these trees are five feet in diameter and may still bear V-shaped scars made by the Indians who collected their sap to make sugar.