There is
no mistaking a beaver-no other Arizona rodent
even comes close to weighing between 30 and
60 pounds and exceeding two feet in length
Moreover, the beaver is uniquely adapted
to an aquatic existence with a flattened,
naked, nine to 10 inch long, oar-like tail,
webbed hind feet, dense fur, and eyes positioned
high on the head. Both sexes are similar
in size and possess pungent scent glands
called "castors" on either side of their
anus. Arizona specimens are typically a light
yellowish cinnamon color in contrast to the
browner animals found in other states.
Beavers were at one time found nearly everywhere in Arizona that there
was permanent water. With settlement, and the desiccation of the state's
streams, beaver populations declined. This habitat loss, and in some cases,
heavy trapping pressure, caused beavers to disappear from such former strongholds
as the San Pedro and Santa Cruz rivers. Introductions and natural colonizations
have since enabled the beaver to recover much of its former distribution,
if not numbers, and these animals can now be found along several permanent
streams, some of the larger river stretches, certain shallow lakes, and
even a few dirt-lined canals.
Natural History
The beaver's diet is almost exclusively plant material with the bark of
cottonwoods, aspen, and willow trees being especially important. Other
reported foods include tamarisk or salt-cedar, mesquite, and the roots
of such tuberous aquatic plants as cattail and bulrush. Even in those places
where beavers are rarely seen, their activities are conspicuous-chiseled
and felled trees, brush dams along small streams and backwaters, and stick
houses or "lodges" constructed either as a separate residence or within
the beaver dam itself. Even more common are "bank houses," dens excavated
in river or canal banks. Whatever its construction, the den will be located
above the water line, lined with cattails and grasses, and will provide
a nursery area for the two to four "kits" or young beavers born in the
spring.
Hunting and Trapping History
The average annual number of beavers trapped greatly declined since 1991
and is now virtually insignificant. Even if the fur market recovers, this
species will probably never again be an important fur-bearer in Arizona
due to the limitations on trapping and the limited areas of quality beaver
habitat remaining.
Habitat
