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THE NATIONAL GEOGRAPHIC MAGAZINE 



mal delights in locations that are cool and 

 oozing with water, where, under the dense 

 shade of an almost tropical undergrowth of 

 shrubs, ferns, and other herbage, it constructs 

 numberless tunnels and trails. These are some- 

 times in flats, but much more often along can- 

 yons and mountain slopes, among willow, alder, 

 aspen, or other thickets, or even in the heavy 

 coniferous forest. 



Veritable colonies inhabit certain areas and 

 the ground is honeycombed with burrows six 

 to eight inches in diameter and covered with 

 a network of surface trails. The irregular 

 branching tunnels are sometimes two or three 

 hundred feet in length and have at frequent in- 

 tervals side passages through which the earth 

 mined in extending the burrow may be ejected 

 in small dumps. The tunnels appear in a large 

 measure built for the safety of the owner in 

 traveling, since they repeatedly come to the 

 surface at the end of a log, where an open, 

 neatly kept trail extends under its shelter the 

 entire length, the tunnel being resumed at the 

 far end of the log. 



All surface runways connecting tvmnel en- 

 trances or leading through the thick surface 

 vegetation are well kept and free of all ob- 

 structions. The ground in these haunts is 

 commonly sO' saturated with water that the 

 lunnels form drainage channels down which 

 run little streams. 



Nest chambers discovered by T. H. Schef- 

 fer in the Olympic Mountains were located in 

 tunnels two feet underground. They were oval 

 in form and one measured eighteen inches in 

 horizontal diameter and seventeen in height. 

 Here three storage chambers opened directly 

 from the nest chamber, one of which con- 

 tained two quarts or more of sections of fern 

 roots, which had been kept so long they were 

 spoiled, and another was partly filled with 

 freshly cut leaves of nettles and twigs of cedar 

 and fir. At the far end an opening dropped 

 six inches into a small drainage basin partly 

 filled with water, out of which led two pas- 

 sages. The roofs of the chambers were lined 

 with a thin layer of clay, which appeared to 

 have been packed in place by the owner. 



In the upper and drier part of the nest, 

 which was made of dried fronds of ferns, 

 grasses, and small twigs, were found three 

 young less than a week old, with coats of fine 

 fur, but with eyes still closed. Like burrow- 

 ing animals generally, the mountain-beaver is 

 cleanly in its housekeeping, and offal, loose dirt, 

 and debris of all kinds are pushed out by the 

 forefeet and head to the dumps at the less-used 

 openings. 



In winter much of the mountain-beaver 

 country is buried under several feet of snow, 

 but this does not stop the activities of this 

 hardy animal. Between the entrances to its 

 burrows and out along the surface of the 

 ground it tunnels through tlie snow in various 

 directions in search of forage. 



At this time it cuts twigs from bushes and 

 gnaws the bark from the trunks and roots of 

 the smaller trees, sometimes completely gird- 

 ling and killing trees more than two feet in 



diameter. Its underground tunnels are also 

 extended at this season, the soils being pushed 

 up in dumps under the snow and parts of the 

 snow tunnels are packed full of it for some 

 distance, so that when the snow disappears the 

 curious earth-forms remain like those of the 

 pocket gopher. 



The mountain-beaver lives a monotonous ex- 

 istence and correspondingly lacks the mental 

 vivacity of many other species which have a 

 greater freedom of movement. When one is 

 caught it shows little fear, but struggles to 

 escape, growling, clattering its teeth, and biting 

 viciously at anything within reach. Its desire 

 for food, however, appears to control its emo- 

 tions, and very soon after being captured it 

 will eat any green vegetation offered, as uncon- 

 cernedly as though free. 



That the mountain-beaver possesses social in- 

 stincts is evident, as a pair is often found 

 occupying one set of tunnels, and in many fa- 

 vorable places a number will have their bur- 

 rows closely grouped and connected with a 

 network of communicating surface trails. 



Although mainly nocturnal, the animals are 

 active early in the morning and late in the 

 afternoon, as well as throughout dark days. 

 Those kept in captivity would show periods of 

 restless activity at night and have alternating 

 periods of sleep and wakefulness during the 

 day. Sometimes they would sleep coiled with 

 the head turned under the body and again flat 

 on their backs. During these periods their 

 sleep is often so profound that they may be 

 handled without being awakened. 



One captive animal is reported to have ut- 

 tered a curious quavering note resembling that 

 of a screech-owl. They have a strong musky 

 odor, which is very evident when they are first 

 caught, and which is frequently apparent about 

 the burrows. 



Careful and repeated efforts to keep these 

 animals in captivity under as near normal con- 

 ditions as possible in regard to food and sur- 

 roundings in the vicinity of where they were 

 captured have, up to the present time, resulted 

 in failure. In every case the animals failed to 

 thrive and soon died. 



The mating occurs about the middle of 

 March, and a month later litters of two or three 

 young are born. The young grow slowly, not 

 attaining full size for a year or more, and do 

 not breed until the second year, but they leave 

 the shelter of the home nest and scatter to 

 occupy burrows of their own at the end of 

 the first two or three months. 



The mountain-beaver feeds upon nearly all 

 small vegetation growing in its haunts, includ- 

 ing, in addition to small herbage, shrubs, the 

 bark of trees and bushes, ferns, and fern roots. 

 More than thirty species of native plants have 

 been found among its "hay" piles at the mouths 

 of burrows. Since its country has become in- 

 creasingly occupied by farmers, it has de- 

 veloped a fondness for cultivated crops that, 

 in many places, is rendering it a pest. It ap- 

 pears to have a special taste for cabbage, po- 

 tato, and onion tops, and other garden produce. 



When gatiiering its food it sits up squirrel- 



