Nature Myths, Debunked

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

Mosses are bryophytes—plants that lack the water-conducting roots and inner vessels, or vascular system, that most plants have to transport water and nutrients to their tissues. Instead, mosses take up water through capillary action and pass the moisture from cell to cell, absorbing it much like a sponge. Because their leaves are extraordinarily thin—only one cell thick in some species—most mosses that get too much solar exposure and/or too little water will dry up and die in a hurry.

It makes sense, then, that in the Northern Hemisphere, where the southern side of a tree gets the most sunshine and the northern side the least, moss would tend to grow consistently on the shady, moist northern side. But several factors complicate matters: Neighboring trees and vegetation may cast shade on a particular tree’s other sides; a rainy climate may keep a tree trunk’s entire lower circumference perpetually moist; and a dry climate or a wind-swept exposure may prevent moss from growing on any side of a tree. So it is, for example, that in the arid Southwest a turned-around hiker may find no moss at all to help point the way home; while in the maritime forests of the Pacific Northwest, moss may completely envelop a tree’s lower extremities, providing little more information on which direction is north than you might discern from a quick game of eeny-meenie-mynie-moe.

A variety of other natural indicators can serve as reliable guides—the sun’s position and movement in the sky at varying times of the day and year; the direction of the prevailing wind; the direction in which hills, ridges or streams tend to run in your area; the North Star at night. But moss as a navigational tool? Don’t bet your GPS on it.

“Raccoons wash their food before eating it.” Of course this must be true; after all, haven’t you seen wildlife films? There’s the raccoon, there’s the stream, and clearly the animal is dunking its food into the water. People have witnessed this behavior for centuries, and the notion is attached to the critter’s identity. The German name for raccoon, wasberen, means “wash bear.” The latter half of its scientific name, Procyon lotor, means “washer.”

Indeed, most scientists subscribed to the food-cleaning theory until early in the 20th century, when the notion was discarded in favor of the idea that raccoons lack salivary glands, and thus need to moisten their food before swallowing and digesting it. This idea persisted until the early 1960s, when researchers found that raccoons do indeed produce saliva. Nowadays, most biologists agree that the raccoon’s water-dunking behavior is associated primarily with locating aquatic prey—a relatively small part of its diet—and that the animal doesn’t willfully wash food in the sense that we do.

RSS | Comments | E-mail | Print