Earth Almanac: March/April 2005

American Nightingale

On moonlit spring nights most everywhere in the nation (save parts of the upper Midwest and Pacific Northwest), birders are apt to get angry phone calls from neighbors, demanding that they turn off the bird tape. The birdsong renditions continue, however, for they issue not from a recording but from the syrinx of the northern mockingbird. Females sing, too, albeit more quietly. The older a mockingbird, the greater its repertoire. Eventually a bird may learn as many as 200 vocalizations, including the calls of frogs and insects. A mockingbird may even imitate the ringing of cell phones or the wolf whistle of teenage boys. In the 19th century a booming pet trade grievously depressed wild mockingbirds. But the species has recovered and is expanding northward. It has benefited hugely from the widespread planting of two thorny shrubs in the rose family—multiflora rose and pyracantha—both of which are major sources of food and shelter in cold weather. In order to eliminate the connotation of deceitfulness that goes with the word mimicry, the “PC bird police” now call the bird's singing behavior “vocal appropriation.”

Blue on Blue

We miss much of the natural beauty that surrounds us because we don't know when or where to look for it. Consider the blue-spotted salamander—slightly longer and thinner than your forefinger and decorated like an antique enamel pot, with azure flecks on a background of glistening blue-black. Although not uncommon in large parts of its range, from New England through the Great Lakes states, this species spends most of its life in the earth or under decaying wood. Most people live and die without seeing one. But for a fleeting time during the first warm rains of spring, often when snow and ice linger in forest and wet meadow, blue-spotted salamanders make their way down from their upland haunts to breed in vernal pools. Look for them at night as they cross wet pavement near water ringing with the sleigh-bell chorus of spring peepers. The blue-spotted and closely related Jefferson salamanders are members of a group called “mole salamanders,” so named for their subterranean habits. Progenitors of blue-spotted and Jefferson salamanders were separated by the last glacier, but when it retreated, the two species shared common range and began to hybridize. Hybrids are generally larger, usually female, and have three sets of chromosomes instead of the normal two.

Marsh Thrashers

As freshwater sheds its ice in Eurasia, Canada, and the temperate United States as far south as Pennsylvania and Nebraska, northern pike ease into flooded marshes. Look for them now as they thrash and wallow, broadcasting eggs and milt. Aptly named for the spear with which medieval soldiers impaled their victims, the pike is an ambush predator, hovering motionless, then charging, flaring its gill covers and opening its huge, tooth-studded, snakelike maw, the better to ingest fish, frogs, crayfish, rodents, even waterfowl. Pike are a special treat both on one's fishing line and on the table. As Izaak Walton noted in the 17th century, their flesh is “too good for any but anglers and honest men.”

Morel Values

Few mushrooms taste better or are safer to eat than morels, and early spring is the time to hunt them—first in the western half of the nation, later in the eastern top half. Few poisonous fungi fruit at this time of year, and only with major effort can morels be confused with occasionally toxic false morels, which are unlikely to kill you anyway. Morels have hollow stems and pitted caps, while the caps of false morels are folded and overhang a stem that isn't hollow all the way through. North America's 10 million morel hunters are as passionate and secretive as anglers—and are armed with as many excuses when they fail to find their elusive quarry: The spring is too hot, too cold, too dry, too wet; or, the oak leaves are still smaller than a squirrel's ear.

Our Favorite Bug

Who, in the otherwise bugless wane of winter, has not plucked a ladybug (a.k.a. ladybird or lady beetle) from an icy window, watched it retract its legs in a charade of death, and fondly bounced it in a cupped palm? No matter where you live in the United States, it is difficult to get far from at least one of the about 450 species of these slow, gaudy, beloved beetles. The French call them les bêtes du bon Dieu, or “creatures of the good God.” Of 329 names for the ladybug in 55 countries, at least 80 refer to the Virgin Mary and more than 50 to God. One reason for the ladybug's popularity is that most species, in both adult and larval form, glut themselves on aphids, chinch bugs, and other pests. In early spring ladybugs emerge from their winter quarters—in your woodwork, perhaps, or in mountain crevices, where a single aggregation may contain 40 million beetles. Ladybugs, gathered from mountains, are available for sale; but they are programmed for dispersal, and, in the unlikely event they stay in your garden, they won't do it much good because they're still in diapause— winter "shutdown” mode, in which they eat little and don't mate. At least six species of alien ladybugs, introduced as controls for alien insect pests, now exist in North America. One of them—the multi- colored Asian ladybeetle, named for its wide variety of markings— can populate human buildings to the point of being a nuisance.

Tunnel Vision

You'll be lucky to see one of these excavators, but early spring is the time to admire the work of pocket gophers—stout, bucktoothed, short-legged, seemingly neckless little rodents named for the external, fur-lined pockets that extend from each side of the face to each shoulder and are used to transport food and nesting material. Thirty-five species of pocket gophers live under open or sparsely wooded habitat, from the Canadian prairies to Panama and from our entire Pacific Coast to South Carolina, Georgia, and Florida. Before new growth gets started, look for the eskers the gophers leave as they tunnel through moist soil with their long claws and yellow incisors, which protrude beyond closed lips. Pocket gophers have enlarged tear ducts that wash dirt from their tiny eyes, and they feel their way through their burrows with long whiskers and sensitive, nearly hairless tails. If threatened, they can turn a quick somersault and reverse direction or run backward with no significant loss of speed. If you see a plant suddenly vanish into the earth, you're not in a Bugs Bunny cartoon. A pocket gopher has pulled it down for food.