160 ANIMAL LIFE IN THE YOSEMITE 



The marmot population of the Yosemite region is to be found chiefly 

 in the Hudsonian Zone and there most commonly about the larger meadows 

 such as Tuolumne Meadows and the floor of Lyell Caiion. The species 

 does, however, in places push down into the upper part of the Canadian 

 Zone, and is found, for example, adjacent to Merced Lake and near Porcu- 

 pine Flat. In these places, the lower limits of its range, it is but sparsely 

 represented. On the east slope only a few individuals were observed by 

 us below the hemlock belt (Hudsonian Zone). Two individuals taken at 

 Silver Lake in 1916 were objects of marvel to the residents of Mono Valley, 

 who declared that they had not previously seen the species there. The 

 only other low record was of an individual observed in a big rock talus 

 near some chinquapin brush on the Tioga Road in Leevining Creek Caiion 

 at 8500 feet. One of the residents of Yosemite Valley, in 1914, told a 

 member of our party that he had once seen a 'ground hog' in the pile of 

 rock debris below Royal Arches on the floor of the Valley. On some of 

 the main peaks of the Sierran crest, such as Dana and Conness, marmot 

 droppings were found well above timber line, at 11,500 feet altitude. The 

 highest point at which a marmot was actually seen by any member of our 

 party was at 11,000 feet in the head of Lyell Caiion. At least three were 

 heard at 11,500 feet on Parsons Peak. 



The Sierra Marmot, like other ground dwelling squirrels, digs a burrow. 

 This it uses as a retreat when seeking escape from enemies, as a place to 

 spend the summer nights, and as a den in which to pass the long hibernating 

 sleep of winter. In the choice of location, the escape from piirsuit seems 

 to be the most important consideration, for the marmot so locates its burrow 

 that any enemy too large to enter the tunnel, for example, a coyote, could 

 only with extreme difficulty get at the marmot in its underground retreat. 

 Adjacence to a supply of food, and safety from flooding at the time of 

 the spring thaw, probably also play a part in the choice of site, though 

 these factors are not always apparent. Many of the local marmots have 

 their headquarters in rock slides where the factor of safety is adequately 

 met. (See pi. 32a..) How far down within the shelter of these heaps of 

 talus rocks the animals go to place their nests we do not know, as the 

 exploration of rock slides is a thing yet to be accomplished by a naturalist. 

 Other members of the local marmot population have their burrows under 

 large granite boulders in meadowland or at the bases of large trees. In 

 either situation an enemy would have great difficulty in digging out the 

 inhabitant. The burrows in meadows are usually on mounds where the 

 water from melting snow would not be likely to flow into the burrow. The 

 diameter of the burrow is usually about 5 or 6 inches. 



Those marmots which live in or along the margins of meadows have a 

 source of food supply close at hand, for this species is more of a grass 



