_Specimens examined._--Total, 2: Young [Male], 76303, November
8, 1957, Far View Ruins; [Female], 76304, November 12, 1957,
Spruce Tree House Ruin, both obtained by J.R. Alcorn.
In all parts of the Park, mule deer are common. Five projects concerning
deer are in progress or have been concluded recently on the Mesa. One is
a study of the responses of different species of plants to browsing and
was begun in 1949 by Harold R. Shepherd for the Colorado Department of
Game and Fish. A number of individual plants and in some instances
groups of plants were fenced to exclude deer. Systematic clips of 20,
40, 60, 80, or 100 per cent of the annual growth are made each year. The
results of the first ten years of this study are being prepared for
publication by Shepherd.
A study of browsing pressure was initiated in 1952 by Regional Biologist
C.M. Aldous, on eight transects in the Park. Each transect consists of
15 plots at intervals of 200 feet. The amount of use of each plant
species was recorded from time to time. The study was terminated in
1955. I have seen no summary of results of this study.
A trapping program was begun in 1953 with the co-operation of the
Colorado Department of Game and Fish. Deer are trapped, marked, and
released. Some are released in areas other than where trapped. In this
way the excessive size of the herd near headquarters has been reduced.
Recoveries of marked deer outside the Park by hunters and retrapping
results in the Park should provide information about movements of deer
and about life expectancy.
The "Deer Trend Study" was initiated in 1954. From November to May,
twice a day, at the same time, a count is made along the entrance road
from the Park Entrance to Headquarters. Ten drainage areas traversed are
tabulated separately. The results of four years of this study indicate
that the greatest number of deer are present in November, December, and
January, and that only about one-fourth as many are present in February
and March. Depending on severity of weather, the yearly pattern varies,
the deer arriving earlier, or leaving earlier. This change in numbers,
the recovery outside of the Park of animals marked in the Park, and
direct observations of movement indicate that the Mesa Verde is an
intermediate range rather than a summer-range or winter-range. In summer
deer tend to move northward and eastward out of the Park, and in winter
they move back through the Park toward lower and more protected areas in
canyons both in the Park and south of the Park on the Ute Reservation.
Some deer remain in the Park the entire year. Close co-operation between
personnel of the Park Service and of the Colorado Department of Game and
Fish has regulated hunting outside the Park in such a way as to provide
satisfactory control of the deer within the Park.
A study of the effect of rodents on plants used by deer was initiated in
1956 by Harold R. Shepherd. Three acres were fenced in a fashion
designed to exclude rodents but not deer. An adjacent three acres were
fenced as a control, but not so as to exclude rodents or deer. Eight
trap lines nearby provide an index of rodent fluctuations from year to
year. These studies will need to be continued for a period of ten years
or more, and should provide much information concerning not only deer
but also rodents and their effect on vegetation.