Some aspects of rabbit ecology in Lyon County, Kansas.

Abstract

A radio-telemetry study of cottontail rabbit mortality was conducted on approximately 100 acres of Ross Natural History Reservation in Lyon County, Kansas. In addition, population estimates were calculated from trap-retrap data, condition indices for rabbits on the study area were calculated, and a daily roadside survey of cottontail activity was conducted. Data were gathered from 1 August 1974 to 1 May 1977. Trapping success was greatest during fall months. For the 274 different cottontails captured, the sex ratio was 1:1.21 in favor of females. A population estimate of 259 rabbits in July was calculated as the peak population density of 2.59 rabbits per acre. In 33 months, 105 cottontail mortalities were discovered. Thirty-seven were wearing a functioning radio-transmitter at the time of death; 60 dead rabbits were discovered by personal observation and the remaining eight were discovered by dogs. Twenty deaths, 19.0 % of total mortality, were classified as research mortalities. Predation accounted for 42.9 % of total known mortality. Cottontail deaths attributed to tularemia represented 18.1 % of total deaths. In one case of cottontail mortality the cause of death was determined to be pneumonia. Condition indices were calculated for 122 rabbits captured from 1 May 1976 to 1 May 1977. The mean condition index was 5.60. There was no significant difference between indices of males and females. A daily roadside survey was conducted from 1 June 1975 to 1 May 1977. A total of 1,575 cottontails was sighted in 7,351 miles traveled, a rate of 21.4 rabbits per 100 miles. Peak roadside activity occurred in July.