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MOUNT RAINIER NATURE NOTES
Vol. XI January, 1933 No. 1


There are Spiders Everywhere
spider web

Of these animals that are more or less familiar to all of us, the spiders probably have the widest world-distribution. Although never occurring in conspicuous numbers like the social insects; honey ee, termite and ant, -- spiders nevertheless can be found in nearly any situation, from the dusty sidewalk of a busy city to the shady coolness of the forest or the windswept arctic prairie. Quietly, diligently they set about making a living and seldom attract the attention of man until their gauzy webs drift across the trail into his face, or offend his sense of neatness as they hang in dusty festoons about his home or office.

How have spiders managed to obtain a foot hold in remote corners of the world and become so familiar a part of outdoor life? Many reasons could be given in answer to this question citing, for example, not only the unique way in which spiders are able to travel great distances across country but also the way in which they are able to adapt themselves in a new location through a wonderful variety of body structure and complexity of instinct. Let us consider only two important factors -- namely the modes of traveling and of capturing food, passing over for the time being a consideration of the ways in which spiders build their homes, rear their young and battle their enemies.

On Mount Rainier, a peak presenting the various characteristics of all plant life zones from Puget Sound to the Arctic Circle, it is difficult to find any considerable area free from some sort of spider, unless it be entirely barren fields of perpetual ice. Even on the stormy summit itself, at an elevation of 14,408 feet, spiders are occasionally seen on the mist covered rocks of the crater. Their mode of approach to this spot that defies the attempt of any mountaineer is called "ballooning" - an art not invented by man but one used by countless generations of spiders in order to reach new "green pastures". The feat is accomplished as an individual crawls to the tip of a tree or projecting rock, spins a tangled, fluffy mass of finest silk and waits for the first wind to carry him sailing away.

Having seen how spiders come to inhabit hitherto unoccupied areas, we are interested to find that it is because of the variety of different modes of capturing food that at least one type of spider will be able to maintain the struggle for existance in any particular habit. Among the sixteen families of spiders which are represented in the Northwest, there are four general ways of obtaining prey. One group - which includes the majority - is sedentary and members have become adept at building intricate webs or snares among grass or low bushes. The hunting spiders form a second group and are not web builders but roam about actively in search of their victims. These dark bodied, fierce-appearing fellows often attract our notice on the barren rock slides of "The Mountain". A third group is made up of the "ambushing spiders" who neither toil nor do they spin but remain hidden under the bark of trees or in the blossoms of flowers until an unwary insect ventures near. The loss of the web building instinct is compensated for by an increased strength of jumping muscles and acuteness of vision. The fourth group is small and is characterized by tiny spiders that live as tolerated guests or commensals in the webs of larger species.

On your next visit to "The Mountain" as you pause beside the trail to rest you may have a chance to observe at first hand a member of one of these four spider groups. If so we hope that you will not be tempted to "squash him", but instead to marvel at his resourcefulness in getting along in the world far better than many human beings.

Victor Scheffer, Ranger-
Naturalist. Season 1932.

spider web

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http://www.nps.gov/mora/notes/vol11-1b.htm
17-Nov-2001