CHAPTER. Vii 
Foop AND TREE CUTTING 
The beaver’s food is exclusively of a vegetable nature, and 
no matter how the ponds and streams in which the beaver 
lives may abound with fish it never harms them. The pre- 
ferred food would appear to be the bark of trees, and it is the 
inner or cambium layer, the one between the outer bark and 
the wood, which is mostly eaten, not the tough outer bark. 
In the case of small twigs, however, or stems like those of 
small willows, it would seem likely that all the bark is eaten, 
the outside layer being too thin to be conveniently discarded. 
While deciduous trees are almost universally used, coni- 
fers are also sometimes utilized. The thick bark of large 
trees is unfit for food, though I have seen large aspen logs 
from which the bark had been eaten and none of the outer 
bark discarded. 
The following trees are mentioned by different authors as 
being used for food by beavers: Aspen or poplar, cotton- 
wood, willow, alder, box elder, different species of birch, 
yellow birch being preferred (Morgan), wild cherry, pin 
cherry, viburnum or witch hopple, black and white ash, 
soft and bird’s-eye maple. 
These food trees vary with the locality, but almost every- 
where the aspen seems to be preferred above all others, and 
in the Rocky Mountain region it is the food tree of the ani- 
mal, for, aside from cottonwoods, willows and alders, the 
other species are mostly noticeable by their absence. 
In the summer beavers would appear to be less dependent 
on bark for food, and eat many other things, perhaps for a 
change in diet, and perhaps as a conservation measure to 
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