Earth Almanac: September/October 2008

The Last Word

Most other frogs stop talking in autumn, but the green frog, which abounds from the East Coast as far west as the Great Lake states and east Texas, can’t quite shut up. Males are far quieter now than in spring and summer, when they were more aggressively defending territories and trying to call in females, but they still insist on getting the last word. They’ll sit for hours, leaving the long, cool evenings to the crickets and katydids, then suddenly announce their presence to the world with a loud banjo twang. The tadpoles frequently endure at least one winter before transformation, so if you see one at this time of year, chances are it’s a juvenile green frog, although another good possibility is the slightly larger, slightly less abundant bullfrog.

The one sure way to determine between adults of these strikingly similar species is by the two ridge lines that run down each side of the green frog’s back. Like bullfrogs, green frogs are voracious predators, glutting themselves on insects, fish, crayfish, other frogs, and even small snakes, mammals, and birds. You can feed green frogs by loosely attaching a piece of fish or meat to a string and dancing it in front of them. If the morsel is large, they’ll stuff it into their mouths with their “hands.”

Stocking Up

In steppes, foothills, and alpine meadows throughout the West, yellow-bellied marmots, a.k.a. “rockchucks,” are stuffing themselves with herbs and other green plants. Rockchucks that don’t put on sufficient fat now will die during hibernation—frequently a more strenuous ordeal than that faced by their close eastern relatives, woodchucks (whether or not they see their shadows on February 2). A hibernating rockchuck can lose half its fall body weight. If weight loss becomes critical, it may avoid starvation by awakening before the growing season and feeding on twigs, a poor but better bet for survival.

Moderate grazing by cattle or wild ungulates benefits rockchucks by removing grass and thereby encouraging the herbs they prefer. Except where they’re hunted as alleged “varmints,” they keep bankers’ hours. Look for them at mid-morning and late afternoon as they sun themselves and forage. Listen for them, too. Alarmed rockchucks utter loud chucks, whistles, and trills. Those making most of the noise are animals that have already run back to their dens.