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.
[Illustration: Hibernating bat in “dry” room]
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.
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.