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Grand Teton National Park Report

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Beavers (Castor Canadensis) are an indicator species of an ecosystems health. To utilize them as an indicator it is imperative to know their location and their foraging and movement patterns. This project examined the foraging characteristics of eight colonies in Grand Teton National Park and completed an aerial survey of their distribution. Overall, the beavers, on average, foraged an area of 1.01ha and traversed 381.1m collecting food, mainly willows (Salix spp.) with some alder (Alnus incana) and aspen (Populus tremuloides). The aerial survey found 22 active caches distributed over Grand Teton National Park. This is a decrease of 52% from the previous survey of the same area completed in 2006 (46). Changes in back water channels and ponds could be a major cause of the decline.