One form of this small animal has been found living at an elevation of
from 15,000 to 16,000 feet on Mt. Orizaba, Mexico, the highest record
of any North American mammal.]
That the small rodents have good cause for their timorous ways is plain
when we consider the array of enemies which encompass them, including
owls, herons, gulls, bears, foxes, bobcats, weasels and their cousins,
with snakes, and on occasion fishes, which take endless toll from their
numbers. Fortunately for them, these small folk live wholly in the
present and quickly forget the shadow of death cast by the passage of a
hawk or the skulking form of a four-footed enemy.