presented the largest segment of the population at that time; for
example, only three of 17 individuals collected from June 20 to 27 were
adults. Adult females collected on June 20 and July 7 had enlarged
mammae but were no longer lactating.

Time of emergence from hibernation in northwestern South Dakota is
unknown, but many ground squirrels were active in the last week of
March, 1963. A male obtained on March 28 had testes that measured 27 and
was in full winter pelage, which is easily distinguished from the
shorter, darker pelage of summer.

~Cynomys ludovicianus ludovicianus~ (Ord, 1815)

Black-tailed Prairie Dog

_Specimens examined_ (5).--Sec. 25, R. 3 E, T. 22 N, 2; 1-1/2 mi. W
Buffalo, 1; 1/2 mi. W Camp Crook, 3200 ft., 2.

The extensive flatlands of short grasses on relatively deep soils
provide ideal habitat for the black-tailed prairie dog in Harding
County. Visher (1914:89) mentioned extensive colonies along "flats" of
streams and reported one "town" west of the Little Missouri River that
covered several sections and another "on the table of the West Short
Pine Hills." Recently, emphasis on control of numbers of prairie dogs in
the area has reduced many formerly extensive colonies to small, disjunct
units. According to Robert Kriege (personal communication, 1968), a
"town" of approximately 3000 acres, about five miles east of the Little
Missouri River (in R. 2 E, T. 21 N), is the largest remaining in the
county. Thirteen other colonies then known to him ranged in approximate
size from 25 to 300 acres.

White-colored prairie dogs apparently are not uncommon in some areas of
the county and local residents reported to us a number of instances of
sighting such individuals. One "town" located 7-1/2 mi. N and 12 mi. W
Ladner, in the northwestern corner of the county, contained at least six
families of white individuals, congregated together at the edge of the
colony, in the spring of 1968. White prairie dogs also were noted by one
of our field parties in 1963 in a "town" formerly located 7-1/2 mi. W
Buffalo.

~Tamiasciurus hudsonicus dakotensis~ (J. A. Allen, 1894)

Red Squirrel

Visher (1914:88) reported that he obtained a red squirrel in the Long
Pine Hills, along the western border of Harding County, in July of 1910
and noted that the species had been reported to him as occurring also in
the West Short Pine Hills. Visher's record evidently has been overlooked
by subsequent cataloguers (see, for e