Earth Almanac: September/October 2001

As summer wanes, larvae of tropical fish, many associated with coral reefs, drift north on the Gulf Stream, settling into tepid bays and estuaries along the Eastern Seaboard, where they metamorphose into miniature replicas of their parents. Offshore shelves are arranged in such a pattern that the south of Cape Cod seems to be the barrier. Drag a fine-mesh net across the shallows, and you may find barracuda, butterfly fish, angelfish, triggerfish, snowy grouper, rock hind, orange-spotted filefish, coronetfish, blue runner, jack crevalle, permit, mullet, and bigeye. For a few weeks these southerners thrive in ideal habitat, but they are stranded in the summer of an alien world. When the year's first nor'easters chill the North Atlantic, they all die.

Polterguests

House mice--ship stowaways from Europe--infest human dwellings. Our cleaner natives--the ubiquitous white-footed mouse and the closely related deer mouse--visit. They arrive in camp by moonlight and starlight, entering like poltergeists through openings unseen and unknown when the first hoarfrost silvers understory leaves and the swamp maples match the embers in your woodstove. East of the Rockies, save in Florida, you may see at least one of these creatures in the light of the dying fire, flowing over floor and hearth, pausing to preen its luxuriant fur and impossibly long tail, fixing you with huge, obsidian eyes. White-footed mice tend to be woodland dwellers, but you're likely to encounter deer mice in most any terrain. Neither species hibernates, so they need your place more than you do. They might shred some paper and poop on the counters; otherwise, they're easy guests. In spring they always leave.

How to Find Cows

When grass goes gold and the bright, still air is full of milkweed silk and cricket song, the daddy longlegs goes a-courting. Now sexually mature and fully grown, these gangly arachnids leave their summer haunts amid dead and living vegetation. Suddenly they seem to be everywhere, which is why farmers of yore called them "harvestmen." Worldwide, there are at least 7,000 species of daddy longlegs, all of which lack the spiders' fangs, poison, and silk glands. Where a spider has two distinct body parts, a daddy longlegs has one, and instead of having eight eyes like a spider, it has two, mounted on a small turret near the front of its body. A male spider must transfer its sperm to the female on the tip of an armlike appendage called a pedipalp. Daddy longlegs, on the other hand, can copulate. A daddy longlegs chews and swallows its prey instead of sucking out the body fluids, and it also consumes fruit and plants. Its second pair of legs--the longest--is used more for sensory perception than locomotion. These are waved at whatever the creature happens to be investigating and always, say country folk, in the direction of cows.