Earth Almanac: March/April 2007

Screams in the Night

The swamps of Georgia, Florida, and South and Central America are spooky, magical places in any season but especially when breeding limpkins—a.k.a. “crying birds”—fill the night with their caterwauling. Shrieking like actresses auditioning for Psycho, males charge one another in mock combat. The cacophony is a sure sign that the rivers have stopped rising, or so aver the people of Amazonia. Much remains to be learned about this strange, goose-size bird seemingly allied to rails and cranes but in a family of its own.

The long, down-curved bill often has a right bend at the tip, perhaps so that it can more easily be slipped into the right-handed chambers of apple snails, the bird’s favorite food. Although the limpkin probably derives its name from its limping gate or possibly its limping flight (characterized by jerky wing beats and dangling legs), it is a fast runner and powerful flyer. Nests—platforms of sticks, vines, moss, leaves, and other vegetation—may be constructed anywhere from high tree limbs to floating islands. Four to eight downy hatchlings leave the nest after only one day and are then tended by both parents.

A Surge of Silver

There’s a special night in early spring when cold-water streams collected by the Pacific and Atlantic oceans and many of our large interior lakes snap to life with a surge of silver. Thousands of fish, rarely longer than a pencil and not a lot thicker, are moving upstream, sometimes clouding the water with eggs and milt. Rainbow smelt, resembling the salmon to which they are distantly related, fuel vast ecosystems that start with larger fish and end with piscivorous birds and mammals. Originally rainbow smelt were restricted to coastal lakes and river systems from Vancouver Island to the Northwest Territories and Labrador to New Jersey. But there have been widespread introductions, not always with happy results because, while the smelt serve as forage for favored game fish such as lake trout and walleyes, they also consume the eggs and fry of these species.

On many eastern and Great Lakes streams it is legal to catch smelts with dip nets, and smelting parties, complete with bonfires and beer, are a long-standing tradition. The smelt derives both its popular and generic name (Osmerus, Greek for “odor”) from its distinctive but not unpleasant smell, reminiscent of sliced cucumber. As table fare the rainbow smelt is excelled by few fish, a fact noted by Ogden Nash, who wrote: “Yet—take this salmon somewhere else. And bring me half a dozen smelts.”

Feisty Squirrels

In the rocky shrublands and piñon-juniper woodlands of our desert West and Southwest, young male white-tailed antelope squirrels are sparring in preparation for breeding. Chattering, chirping, and growling, they box and wrestle until they establish a dominance hierarchy. Antelope squirrels are the only ground-nesting squirrel genus that can avoid hibernating in winter and estivating in summer. They deal with heat by shading themselves with their tails, anointing their faces with saliva, climbing bushes to take better advantage of airflow, and conserving water with extremely efficient kidneys. Unlike other squirrels, they don’t usually dive into their burrows or climb vegetation when threatened. Instead they run, tails up to reveal their flashy white undersurfaces resembling the rumps of their namesake.

Pansies in Bloom

For two or three weeks in early spring, woodlands, ravines, and stream banks from New York to Wisconsin and south to Texas and Florida brighten with the prolific blooms of eastern redbud, also known as “forest pansy.” They’re not red, but range from pink to pale purple, sometimes even white. Flowers, pollinated by bees, appear before the heart-shaped leaves. The fruits, which resemble pea pods and contain seeds relished by such birds as quail, pheasants, and goldfinches, may linger on the tree for more than a year. Members of the pea family, these medium-size trees enrich the soil by fixing atmospheric nitrogen, a fact that adds to their popularity as ornamentals inside and outside their natural range. Flowers, pickled or raw, are popular in salads.

Crested Dancers

In most of the nation, save a swath through desert states, hooded mergansers—the smallest of our three merganser species—are returning from their winter range. They haven’t been away long or come from any great distance. They’ve just been hanging out in ice-free water. Watch for their dramatic courtship displays. Several males may pursue a female, raising their spectacular white crests, shaking or pumping their heads, stretching and flapping, and uttering a froglike crraaa-crrrooooo. Females respond by bobbing, jerking their heads up and down, and uttering a hoarse gack. Though awkward on land, hooded mergansers are superb divers, gaining crisp underwater vision by means of a third, transparent eyelid. Females nest in tree cavities or nest boxes. For nest-box plans, log on to www.birds.cornell.edu/birdhouse/pdf/boxwodu.pdf.

Sun Worshipers

We associate basking turtles with the blazing heat of high summer. But the best time to look for spotted turtles—one of our smallest and most beautiful species—is a bright, chilly day in late winter or early spring. When vegetation is still low in shallow wetlands from Illinois to Maine and south along the Atlantic coast to Florida, these semi-aquatic turtles emerge from their communal hibernacula and soak in solar heat. Because of their diminutive size (rarely more than four and a half inches long) you’ll have better luck if you bring binoculars or a spotting scope.

Look for them on logs and muskrat houses. Throughout the central and southern parts of their range, courtship starts about now, and if you don’t find baskers, you may encounter males frantically chasing females, sometimes under shell ice or between islands of snow. Several males may pursue one female, biting at her and one another. Eventually, she’ll let one catch up, place his concave plastron atop her convex carapace, and mate. She can store the sperm for up to five years.