Earth Almanac: April/June 2004

Flying Plaid

Now, mostly east of the Rockies, cecropias—the biggest and, by almost any standard, most beautiful moths in North America—are struggling from their cocoons and pumping hardening fluid into their wings, which can measure almost seven inches across. The corpulent body is red plaid, the wings intricately patterned with white and black eyespots and borders, and rich shades of reds, chestnuts, and browns. The species is not uncommon, especially in suburbia, where there's an abundance of small trees, and where white-footed mice, the insect's main predators, are less abundant. So why haven't you seen a cecropia? For one thing, they fly swiftly and mostly at night; for another, they don't live much longer than a week. Sex is the single mission of an adult—it doesn't even feed. With his large, feathery antennae a male can detect and home in on female pheromones from at least a mile away. To see an adult up close, find a few of the caterpillars; they're light green with head bristles and red, yellow, and blue warts—and they'll be feeding on leaves of maple, cherry, plum, willow, apple, alder, birch, and dogwood. Keep them in a cool, shaded, screened-in area, and supply them with fresh leaves from the tree you found them on. They'll spin their cocoons in autumn and emerge the following May. Don't wait too long to release the adults.  

Night Bard of Spring

Of all night creatures, none has stirred more human hearts, communicated more eloquently the magic of the springtime woods, given rise to more superstition, and inspired more bad poetry than the whip-poor-will. So cavernous is the mouth of this stocky, bewhiskered insect eater that farmers of yore theorized that the bird clamped onto the teats of she goats, draining them of milk. Hence the family name goatsucker. Some goatsuckers, including the whip-poor-will, are also called nightjars, but impoverished is the soul “jarred” by the sweet, clear song. Listen for it after dusk in open forests and meadow edges of the East or in wooded canyons of the Southwest. In perhaps the most wretched of all whip-poor-will verse, Harry Graham (who didn't understand that the bird doesn't sing on the wing) wrote: “You can hear the desperate song of the lonely fowl in flight / As perambulations and melancholy becomes the fowl's delight.” Young women used to pay careful attention to whip-poor-wills. A single vocalization of whip-poor-will meant the listener wouldn't get married for at least a year; two meant she would die a spinster. Fortunately, whip-poor-wills are almost always more persistent, offering as many as a thousand repetitions without respite.

Speed Demon

In brushlands, grasslands, and deserts of the American West, mid-spring is birthing time for the pronghorn, an ancient ice-age survivor also called “antelope” (although it isn't one). The doe, which also has horns, literally drops her fawns (usually two) from a standing position. Four days later they can outrun a human. Pronghorns, not closely related to any other ungulate, are uniquely North American. Once they were at least as numerous as bison, on which they depended, eating the forbs that flourished in grazed-over areas. The fastest land mammal on earth after the cheetah, the pronghorn apparently evolved to deal with the cheetahs that were once native to this continent. We almost lost the pronghorn to unrestricted market hunting. But organized sportsmen and state game and fish agencies have brought about such dramatic recovery that the species is now safely hunted throughout most of its range.

Ugly But Beautiful

Spring is the time to look for sea lampreys as they sashay up unobstructed Atlantic rivers from the Gulf of St. Lawrence to north Florida. These jawless, cartilage-framed relicts from the Pennsylvanian period spend four or more years as toothless, eyeless, mud-dwelling larvae. After transforming into free-swimming vampires and migrating to sea, they spend about 18 months attaching themselves to other fish, excavating holes with tooth-studded disks, and sucking body fluids. Now, on their one-way spawning migration, teeth fall out, eyes rot away, and patches of fungus bloom on gray-yellow skin. Shortly after spawning, they'll all die. Why would you want to seek out such creatures? Because they're part of something beautiful—in the sense of, say, Helen of Troy's liver. For one thing, they've been around longer than the first dinosaurs and even the first flowering plants, and therefore function in aquatic ecosystems in ways we only begin to comprehend. Nesting adults clear gravel from streambeds, improving spawning habitat for salmonids. Larval lampreys keep bottom sediments loose, maintaining spawning habitat for other fish. Sea lampreys are food for all manner of predators and scavengers, and they funnel rich ocean protein into sterile, glaciated feeder streams. The species, however, lacks such beauty in the upper Great Lakes, where, as an alien invader, it devastates native lake trout and other fish that have evolved no defenses.