f
the colony in Prater Canyon the year before.

If prairie dogs were able to survive primarily because of over-grazing
by domestic animals, future introductions may fail. If disease was the
major factor in their disappearance, reintroductions may succeed.

Spermophilus lateralis lateralis (Say) Golden-mantled Ground Squirrel

_Specimens examined._--Total, 10: highway at School Section Canyon,
MV 7894/507; Sect. 27, head of east fork of Navajo Canyon, 7900
ft., 69265; and Prater Canyon, 7600 to 7800 ft., MV 7835/507,
7837/507, 7846/507, 7874/507, 7875/507, MVZ 74411-74413.

In 1956, I observed _S. lateralis_ 1/2 mi. W of Park Point, 3/4 mi. WSW
Park Point, in the public campground at Park Headquarters, at the lower
well in Prater Canyon, and at two other places on the North Rim. Other
observations on file were made at Prater Grade, Park Point, "D" cut (on
North Rim 1 mi. WSW Park Point), and Morfield Canyon. A juvenile was
noted at Park Point on June 28, 1952, by Jean Pinkley, and five young
were seen together at "D" cut on July 3, 1935. The earliest observation,
also recorded by Jean Pinkley, was on February 1, 1947. All of the
localities with the exception of Park Headquarters are above 7500 feet,
and most of the localities are in vegetation that is predominantly
oak-brush.

Spermophilus variegatus grammurus (Say) Rock Squirrel

_Specimens examined._--Total, 6: Head of Prater Canyon, MV
7876/507; Chickaree Draw, Prater Canyon, MV 7843/507, 7844/507;
Headquarters Area, MV 7888/507; Ruins Road 1/2 mi. NE of Cliff
Palace, MV 7893/507; and Spruce Tree House, 4334 in Denver Museum.

Specimen number 7893/507 had 360 Purshia seeds in its cheek-pouches
according to a note on the label. On July 18, 1960, I found a young male
rock squirrel dead on the road a mile north of headquarters that had 234
pinyon seeds in its cheek-pouches. Young, recorded as "half-grown," have
been observed in May and July. The first appearance may be as early as
January. In 1950, D. Watson thought that they did not hibernate, except
for a few days when the weather was stormy. I observed a rock squirrel
in August in the public campground at Park Headquarters sitting on its
haunches on a branch of a juniper some twelve feet from the ground and
eating an object held in its forefeet. The rock squirrel ranges
throughout the Park in all habitats.

Eutamias minimus operarius Merriam Least Chipmunk