An Attempt to Use the Leslie Census Method on Deer

Abstract

In 1948, white-tailed deer (Odocoileus virginianus) were released within a 2,500-acre enclosure on the Clarksville Naval Base, Tennessee. By 1957, herd control was necessary and deer were trapped and removed as part of a deer restoration program. To facilitate maintaining the herd at moderate levels, an estimate of its size was needed. The Lincoln index was used for this purpose in 1961 and 1963. The 1958-65 trapping program provided an opportunity to apply the Leslie census method, which involves plotting trapping success against cumulative removal and extrapolating to the number that will be removed when trapping success becomes zero. This method underestimated herd size because we were unable to meet one of the conditions for its use: that the vulnerability of the population not change during the census period. Salt was the only bait used for trapping and apparently the deer's physiological desire for salt increased in the spring and decreased in the fall. The Leslie method will be more suitable for deer census in these circumstances when we can accurately quantify the seasonal changes in catchability. In 1948, six Texas white-tailed deer were released by U. S. Navy personnel within the ammunition storage depot of the Clarksville Naval Base. This depot, located near Clarksville, Tennessee, contains approximately 2,500 acres enclosed with three deer-proof security fences. No hunting was permitted within the depot until the fall of 1966 when a few bucks were removed by military personnel, and no dogs or other predators were present, so the herd grew rapidly. Security restrictions have not permitted cover mapping or a browse survey of this depot, but an estimated 50 percent of the area consists of old fields containing favored deer browse plants like sassafras (Sassafras albidum) and sumac (Rhus spp.). The remaining area contains scattered oak-hickory woodlots, brush, roads, and buildings. By 1957 the vegetation showed considerable evidence of being overbrowsed. Browse lines were apparent on red cedar (Juniperus virginianus) and other vegetation. U. S. Navy personnel asked the Tennessee Game and Fish Commission for suggestions on controlling the herd. The only 1 Present address: Oklahoma Cooperative Wildlife Research Unit, Stillwater, Oklahoma. 760 solution seemed to be to remove deer by trapping, because military security regulations would not permit shooting or public access. The Commission proposed to use the trapped deer in their restoration pro-