Ecology of the Bobcat in South-central Florida

Abstract

The ecology and life history of the bobcat (Felis rufus) were studied on the protected Archbold Biological Station and surrounding semi-developed land in south-central Florida from 1979 to 1982. Mean densities were 5 adult males, 8 adult females, and 13 juveniles/100 km2: Overall adult sex and age ratios were 0.64 male/female and 1.00 juvenile/adult, respectively. Breeding occurred from August to March, with a peak in February and March. The mean size of 13 mobile litters was 2.6. Of 17 radio-collared cats, 9 died during the study, and 9 unmarked individuals were found dead or reported killed in the study area. A higher proportion of mortality (73%) was due to natural (feline panleucopenia and Notoedric mange) than to man-related causes. Cottontail rabbits (Sylvilagus floridanus), marsh rabbits (S. palustris), and cotton rats (Sigmodon hispidus) were the primary prey species, comprising 73% of the occurrences of food items in scats and 86% of estimated prey biomass. Overall home ranges of 5 adult males and 7 adult females averaged 25.5 km2 and 14.5 km2, respectively. Short-term home ranges during 12 intervals of 3 to 16 weeks averaged 14.5 km2 for males and 9.3 km2 for females. Females tended to use their home ranges more intensively than did males, but males moved farther from day to day than females. One adult female and one male adult were known to abandon their ranges, the female's range apparently being acquired by her male and female young. Adults of the same sex had non-overlapping home ranges, but ranges of males and females overlapped extensively. Adult males and females with shared home range areas occasionally travelled or together in all seasons. Activity was primarily crepuscular and nocturnal. Seasonal variation in activity of males appeared to be related to temperature and in females to care of young. Both sexes used natural vegetation types more than man-modified habitats, with males using man-modified habitats relatively more than females. Marking behavior varied seasonally and appeared to play a significant role in maintenance of home range boundaries of adult males and adult females. Compared with data from other parts of the range, the south-central Florida population had an average density comparable to values reported from elsewhere in the southern U.S. and somewhat higher than levels recorded in northern areas; relatively low litter size; comparatively small home range size; and a possibly higher frequency of cases of a single adult female range contained entirely within an adult male range suggestive of a facultative monogamous relationship. Implications of the study to conservation and management of bobcats are discussed.