The Underworld of Oregon Caves
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If the Indians of southwest Oregon knew of Oregon Caves they left no evidence of the fact. Possibly its remote and rugged setting was too far away from their normal haunts near the fertile valleys and salmon-rich rivers. Or they may have known of the cave, but superstitions forbade their entering it. To our knowledge, Elijah Davidson was the first person to penetrate its depths.

Other creatures used it regularly. Bears, mountain lions, coyotes, bobcats, skunks and other predators found the outer chambers ideal dens or resting places. Within the "twilight zone"—the galleries near the surface where some light penetrates—rodents of several kinds entered freely and even made nests. Today, we find the industrious woodrat still gathering mounds of sticks, leaves, flashbulbs, and hairpins to store near the 110-foot exit. Mice and rabbits are frequently seen in the cave. Occasionally the tracks of the ringtail betray his secretive hunting trips into the cave. In 1935, even a mountain beaver was found in the Ghost Room.

However, there is only one mammal truly adjusted to normal living inside the dark portions of the caves. This is the bat. (See illustration below). There are eight species of bats that use Oregon Caves. Most common is the long-eared myotis. None are abundant, and most visitors do not see them, for this is not a "bat cave" in the same sense as Carlsbad and other caves. Also, the bats prefer the undisturbed sections of the caves, where people seldom enter. In spite of this, they attract much interest and are the subject of much discussion. The only mammal capable of flight, bats are also unique in their ability to fly in total darkness deep within caves.

This latter skill puzzled scientists for many years until, in the 1930's, it was learned that bats navigate in darkness by echo-location, a system similar to the Navy's sonar. The animal emits high-pitched squeaks, above the threshold of human hearing. The echo of the squeaks bounces off nearby objects and the bat is able to decipher, from a flood of up to sixty echoes a second, the size, shape, and distance of objects before them. So precise is this system that the animal is able to locate and capture flying insects in pitch darkness. Not only can they navigate in the dark, they can also remember echo patterns that help them to return again and again to the same place deep inside a cave.

They feed at night, eating great numbers of insects. In winter a few of them hibernate in Oregon Caves and may be easily observed clinging head downward from the walls and ceilings for months at a time. During a bat-banding study a few years ago, 750 bats were fitted with tiny aluminum identification bands and released. To date, however, none of these bats have been found elsewhere, nor have any foreign bands turned up here. Some bats are migratory, for each year in late August or September there is an influx of several hundred that may be seen in the caves for only a few days. Then they are gone again.

Hibernating bat in "dry" room

Certain arthropods—millepedes, spiders, moths and small wingless insects called collemboles are abundant in the "twilight zone" of the caves, where they feed on organic matter and upon each other. Thus animal life in the cave is more prominent than many people suspect.

Plant Life

When the cave lights were installed in 1932, conditions were established for the entrance of another type of life—plants. Carried into the cave by water or air currents, spores of primitive plants could now germinate and live. Near the light fixtures we find interesting colonies. The green coating several feet from the lights are clusters of algae. They have no leaves, stems or roots; in fact they are the simplest and most universal of the earth's green plants. They require much less light energy than the mosses which grow only a few inches from the lights. In one or two places we also find fleshy green liverworts which look like blobs of spilled paint. And now and then we find the cave's highest type of plants, the sword ferns. Diminutive in comparison with their kin outside the cave, these tiny ferns are nevertheless able to survive near the lights which burn at least part of every day during the year.

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Last Updated: 10-May-2006