Earth Almanac: July/August 2004

Winged Tonic

For those dispirited by the notion that humanity has doomed itself to a lonely, sterile future in a world increasingly bereft of wild creatures, there is no tonic more curative than the peregrine falcon. Today, on cliffs, bridges, and city buildings nationwide, young peregrines are strengthening their wings. Within a few weeks, those wings will propel them at speeds near 250 mph, enabling them to kill birds as large as great blue herons, mostly by impact. City aeries are frequently monitored by TV cameras, and you can watch the progress of the hatchlings on your computer or television. (Do an Internet search to find the monitored aerie nearest you.) Before World War II the peregrine was among the planet's most successful species, breeding on every continent and many mid-ocean islands, from the Arctic to as far south as Cape Horn. When University of Wisconsin biologist Joseph Hickey surveyed eastern peregrines in 1942, he found 350 breeding pairs. In 1963, after two decades of DDT use, he found none. But in 1972 the Environmental Protection Agency banned DDT, and soon an alliance of federal agencies, conservationists, and private groups was sponsoring captive breeding and the "hacking" of young peregrines into the wild. The recovery goal had been 631 breeding pairs in the United States and Canada. By 1999, when the peregrine was taken off the Endangered Species List, there were at least 1,650.

All Hiss, No Bite

Throughout most of the contiguous United States, early summer finds the stout, aptly named hognose snake laying her eggs. In late summer hatchlings cut through their shells with egg teeth and immediately take up the hunt, mostly for small amphibians. It is probably no coincidence that the eastern hognose sometimes resembles the timber rattlesnake, while the western hognose appears to be modeled after the prairie rattlesnake. Also known as "puff adders" and "blow vipers," hognose snakes respond to perceived threats by coiling and rattling their tails against leaves or grass, puffing up their bodies and flattening their necks, hissing and striking (though almost never biting). If this fails, they roll on their backs and feign death, sometimes emitting drops of blood from gaping mouths and cloacae. Turn a "dead" hognose on its stomach and it will roll over on its back again. The nonvenomous hognose lacks fangs, but it has enlarged rear teeth, perhaps designed to puncture toads that have inflated themselves as a means of defense.