The caracal, Felis caracal caracal Schreber, 1776, as predator in the West Coast National Park

[摘要] ENGLISH ABSTRACT: Small mammals were sampled in eight different plant communities in the West Coast National Park and on two farms adjacent to the Park, and along various slopes in the Postberg Nature Reserve section. Rhabdomys pumilio was by far the most abundant species at all sites, although its density varied between plant communities and seasons. Species diversity, absolute and relative density, cover preference and breeding activity of some small mammals and density, group size and habitat preference of the main bird prey species are also discussed.A low incidence of larger prey, e.g. antelope, hyrax and hares in caracal scats probably reflects their low densities in the study area. Together with caracal, the diet of four other sympatric carnivore species was also examined by analysis of scats collected over a 14-month period in the West Coast National Park. Dietary patterns of all predators studied correlated with fluctuations in densities of main prey species, as well as group size of certain prey species. Food niche widths accordingly changed seasonally, being widest during spring and then contracting gradually towards winter. A considerable amount of food niche overlap existed betweencarnivore species pairs. The main prey item of all the carnivores examined were rodents (mainly Rhabdomys pumilio and Otomys unisulcatus), which were utilized heavily throughout the year, despite marked declines in rodent numbers towards winter.Habitat use by five transmitter-equipped caracal (Felis caracal Schreber 1776) indicated that they spent most of their time active in specific areas where highest rodent density and species diversity were found. Males were active for 45-180 min.in a given area (patch) before moving, without stopping, to another patch; females covered their ranges more uniformly in space. The mean home range size (26.97 ± 0.750 km2) of two males inhabiting the same area, but at different times, was 3.6 times larger than that of each of three females (7.39 ± 1.68 km2). Home ranges overlapped both within and between sexes. Caracal were mostly nocturnal, but werealso active during daytime in the colder winter. No correlation was found between degree of activity and cloud cover, full or dark moon, wind speed, or rain, but asignificant correlation existed between degree of activity and temperatures above 22°c or below 20°c. Mean litter size was 2.25 ± 0.96, with kittens staying ca 120 days with their mother in her territory. This four-month period coincided with the time when most springbok were predated on and when the highest stock losses were reported on farms in the surrounding Swartland Divisional Council.The impact of caracal on introduced springbok at Postberg Nature Reserve section of the West Coast National Park was studied to aid in the decision of whether springbok can be kept in that section of the Park or not. This study contributes to the conservation and control of caracal in the West Coast Strandveld.

[发布机构] Stellenbosch University