Nature Notes From Crater Lake
Volume 18, 1952
Gray Diggers and Muskrats
By Richard M. Brown, Ranger-Naturalist

Gray Digger |
An adult male Douglas ground squirrel,
Citellus beecheyi douglasii
Richardson, was found dead along the west entrance highway about four
miles within the park boundary, on July 15, 1952. This animal, also
known as the gray digger, was noticed by Art C. Toth, foreman of the
fire guards, who brought it to Park Headquarters to be added to our
mammal collection (CLNP # 522). Although these ground squirrels have
been observed occasionally along the western and southern boundaries of
the park, the only other collection was made in 1937 at the south
entrance (Walks, 1947:53). Since the previous observations within the
park have all been made near the west entrance (4800) feet and the south
entrance (4400) feet, the finding of this mature individual, apparently
killed by a car, at an elevation of about 5700 feet establishes a new
record for Crater Lake National Park.
The gray digger lives principally in
sagebrush areas of the Upper Sonoran Zone and open forests of the
Transition Zone. Somewhat similar to the silver gray squirrel,
Sciurus griseus griseus Ord, which is rare within the Park, the gray
digger is distinguished by his less bushy tail and the conspicuous black
patch which extends from between the shoulders to the middle of his
back. In addition, the silver gray squirrel usually stays fairly high in
the trees, while the ground squirrels rarely climb more than a few feet
off the ground.
On June 12, 1952 a muskrat (CLNP #519)
was found by Chief Ranger L. W. Hallock and Assistant Chief Ranger James
W. B. Packard, frozen in a snow bank about twenty-five yards east of the
intersection of the north road with the rim drive. Later this year, on
July 24, a live muskrat was seen by Rangers Edmund J. Bucknall, John C.
Wright, and Merrill H. Newman in the headlights of their car at the
Annie Spring traffic circle. These are the most recent of several
collections and observations which have been made since 1933 (Walks
1947:73).
Many of these records have been in
areas in which it seems unlikely that muskrats, which prefer regions
having abundant water, would establish permanent homes. However, the
known occurrence of three of these animals within the park in the last
two years would lead one to suspect that they have become established in
one or more restricted localities (Yocom 1951). Since the natural range
of the native muskrats does not extend into this region, the most
reasonable explanation as to the origin of these individuals is that
they are descendants of animals which were introduced several years ago
in the Upper Klamath Lake region for purposes of fur farming (Huestis
1938).
References
Canfield, David H. 1933. Gleamings
[sic] of the Chief Ranger.
Nature Notes from Crater Lake National Park, 6(1):12.
Huestis, Ralph R. 1938. Muskrats in
Crater Lake National Park.
Nature Notes from Crater Lake National Park, 11(2):22-23.
Wallis, Orthello L. 1947. A Study of
the Mammals of Crater Lake National Park. Unpublished Master's thesis,
Oregon State College, Corvallis. 91 pp.
Yocom, Charles F. 1951. Muskrat Record.
Crater Lake Nature Notes,
17: 9.