Nature Notes

Vol. II April-May 1984 No. 3


Pacific beavers (Castor canadensis pacificus) have been active throughout Mount Rainier National Park at least as long as there have been people around to watch them. The beavers tend to colonize at elevations below 4500'. Steep mountain terrain and heavy snow packs deter the beavers from colonizing at higher elevations. The snows that accumulate at elevations above 4500' generate tremendous runoff in the spring which would literally wash away the beaver dams and lodges. The lower elevations where the terrain is less severe and the water flows at a slower pace is much more inviting to the beaver's instinctive need to regulate the water's flow.

Beavers colonize areas that allow them to build a dam and create a pond. These areas must also provide a sufficient supply of food which would support a growing beaver colony. The beavers herbaceous diet includes bark, roots, herbs, leaves, water plants, and protein rich pond algae. In the park, the beavers prefer the inner bark of willows, alders, and maples supplemented by numerous water plants. Beavers have been seen cutting down softwood trees such as spruce, fir, cedar, and hemlock, but the beavers do not feed on these trees. These softwoods are toppled for use as supplementary building material for dams and lodges. The beavers scoff at sappy cuisine and prefer a hardy menu.

Once the beavers choose an area adequate to support a colony, their cycle of life begins. The monogamous adult male and female will spend the summer and fall constructing a dam, lodge, and a food cache. Beavers do not hibernate in the winter but stay active inside the lodge. Their activity in January and February produces a litter of one to six kits, four months later in April or May. These baby beavers remain with their parents for two years and then are strongly encouraged to move on. Forcing the 2-year olds out prevents overpopulation which would cause a rapid depletion of the food supply. Parent beavers have been known to kill their offspring to prevent the chance of inbreeding or the spread of infectious diseases if the 2-year old decided to stay. Most 2-year olds will travel downstream to avoid the beaver dams upstream built on headwaters. The beavers in the park also tend to avoid the higher, unsuitable elevations.

Life in Longmire

Beavers have inhabited the Longmire meadow area probably as long or longer than the first white settlers in the park; the James Longmire family. At the turn of the century, Maude Longmire records the beginning of the Longmire beaver chronicles by a written reminiscence: "There was a beaver dam about half way to the Iron Mike Spring and all that meadow was a lake. Grandfather (James) made a boat for Grandmother and I to paddle around the lake in our spare time." Over ninety years later, in October of 1983, a re-creation of Maude's boat trip was launched to again paddle around the Longmire ponds and document the beaver's activity. Visitors and residents of Longmire have, for almost a century, been entertained by these prodigious rodents and have continued to record the beaver's behavior since the Longmires settled Longmire Springs.

Several beavers were living in Longmire Springs until 1896. Then a trap was set and the beavers died for the price of a pelt. During this same period, Ben Longmire was busy trapping Pacific river otters, a natural predator of the beavers. River otters proved to be less resilient than the beavers and were determined to be extinct in the park by 1905. Then, in 1939, an otter was sighted in Reflection Lake and sporadic sightings have since occurred.

Beavers were not seen in the meadows again until 1931 when Superintendent Macy recorded the beaver's return after a 20-year absence. Beavers continued to thrive throughout the 1930's and 40's. As the natural cycle of the meadows revolved, the beavers were again absent from 1950 to 1970 as the meadow took time to replenish and renew. Then in 1970, Park Ranger Dale Thompson reported the beaver's return after a second 20-year absence. The beavers continued their activity under the eyes of park rangers and visitors from 1977 up until the 19th of July, 1983, when the last beaver sighting was recorded.

Beaver activity was reported in 1943 along the stream that flows from the meadow under the road southwest of the National Park Inn. A dam is visible but a separate lodge is not. Numerous softwood trees located a distance away from the dam have been downed along with alder trees much closer to the dam site. In December of 1981, beavers were seen crossing the snowy road from the meadow to the site below the National Park Inn. No beavers have actually been observed working in this area.

The beavers extended their tenancy in the Longmire meadow in ways that would maximize their food supply. They continuously worked to raise the height of the dam so the water level would rise and put additional food in their reach. In 1938, the beavers built a second dam just upstream from their main dam. Canals form a maze in the meadow that enable the beavers to transport food to their lodge because local food sources were exhausted.

Today, the ponds show a buildup of "pond scum" or green algae that was not abundant when the beavers were active. Other plants that the beavers like to feed on have grown up on the old lodge and under the still waters. The fresh mud plastered on the lodge which indicates busy beavers preparing for winter is missing this fall. Grass grows on the dams replacing the sticks and mud of an earlier time. This lack of activity indicates that the beavers have come to the end of yet another cycle.

Have the beavers moved on? The evidence indicates they have.

But the unique habitat that the beavers have created over the past 100 years still holds our interest and fascination in this furry brown mammal. Studying the habits, behaviors, and physiology of the beaver is an engaging pastime and one that has filled many enjoyable hours by park employees and visitors alike. Just as the Longmire family has a history born in that quiet meadowland, so does the beaver. They leave a legacy just as cogent as that left by the Longmire's. Maybe even more so.

Nancy Pierce

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