Nature Notes

Ashford, Washington

Vol. II July-September 1987 No. 13

Nature Notes is issued by the Naturalist Staff of Mount Rainier National Park. Material contained herein may be used freely in any manner, provided credit is given to this pamphlet and the author.
William F. Dengler
Chief Park Naturalist
Neal G. Guse


Aldo Leopold, the patron saint of environmentalists, wrote that much of a person's appreciation for an area and its creatures stems from what the person knows about them. It is not so much the area of the creature itself which evokes fond feelings, you see--it's the unseen facts. For example, the fact that Mt. Rainier is a volcano adds appreciably to the big hill's mystique.

But tidbits of fact about far smaller things enhance our pleasure also. Mt. Rainier, for instance, is home to both Lewis's Woodpecker and Clark's Nutcracker. Yes, that Lewis and that Clark. Stop and think:

When you drag an expedition the size of Lewis and Clark's through that much hinterland, you cannot go about glibly collecting every little trinket that meets your eye. You'd sooner be up to your ears in dunnage that weighs a ton and serves no practical use. And yet, they did bring back study skins of both the unique pink woodpecker and the gaudy nutcracker. The study skins, collected on the westward journey, traveled thousands of miles across half a continent and back again. They journeyed east to Philadelphia. There the founding father of ornithology, Alexander Wilson, introduced the birds to the world in his nine-volume classic, American Ornithology (1805-1814).

But even if you don't know all that, you can appreciate Clark's Nutcracker and Lewis's Woodpecker simply for what they are--unique strands in the living web a around Mt. Rainier.

Sandy Dengler


The banana slug (Ariolimax columbianus) is the Pacific Northwest's only native slug. Most people tend to overlook the seemingly mundane life of the banana slug found in and around Mt. Rainier National Park. The banana slug actually leads a rather unusual and exciting life being a cannibal at times and also a hermaphrodite at other times.

Banana Slugs belong to the mollusk family. Their life span is from one to three years, but they can live up to seven years. They can grow up to twelve inches long and up to a quarter of a pound in weight. The banana slugs' coloring ranges from slate green to yellowish with black splotches mixed in.

Locomotion is accomplished by expending a mucus substance from their head area that is both sticky at times and slick at other times. They move from the rear end first in waves of constrictions and expansions reaching speeds up to .007 miles per hour.

Not being water-proof can be one of the banana slugs' biggest problems. They have no way to control the water coming into their bodies and thus are capable of drowning. On the other hand, if they don't have enough percentage of water in their bodies they will die. So banana slugs tend to be most active at dusk and dawn when humidity is around 100%.

The Northwest's native banana slugs are "laid-back relatively innocuous creatures" when compared to introduced species of slugs, according to Dr. Ingrith Olsen, a Washington Zoologist interested in slugs. Their diet can at times consist of anything from each other to animal scats, but usually would include native herbs, lichens, mushrooms, and ripe fruit.

Banana slugs have a very elaborate courting and mating ritual which may last up to 36 hours! Banana slugs start life out as males and then switch later on. If there is no male around to fertilize the female's 50-75 pea sized eggs she is fully capable of doing it herself.

As a whole, the slugs' main problem is that they are being pushed into a smaller area both by the more aggressive exotic species of slugs and by man's increasing urban expansion which greatly reduces their habitat. So this laid-back interesting native mollusk unfortunately has the possibility of extinction in its future.

Evony Smith

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