A comparison of habitat use by the mountain lion (puma concolor) and kodkod (oncifelis guigna) in the southern neotropics with implications for the assessment of their vulnerability status

Abstract

This study investigates the population density and habitat utilisation of two felid species in the southern Neotropics, the kodkod Oncifelis guigna and the mountain lion Puma concolor. Information on habitat utilisation provides an insight into which landscape features or disturbances are likely to influence overall species' distribution and density and is relevant to the identification of key habitats for these predators. A variety of data are discussed including population density, body size, and species resilience in the assessment of the vulnerability status of each species and the likely effect of habitat fragmentation and impoverishment on their populations. The mountain lion was studied in an area subject to a high level of human activity in a commercial forestry system in Southern Brazil. Density in a 100 km(^2) core area was calculated based using track counts and camera-trap methods, resulting in an estimate of 0.06-0.09 and 0.09-0.12 individuals per km(^2) respectively, including adults and sub-adults. Home range of one female mountain lion was estimated 75.5 km based on radio-tracking. The diet of the mountain lion was analysed, and a model for calculating standing prey biomass and numbers were derived from it. The density of kodkod estimated from radio-tracking data was 0.97 individuals per km(^2). Mean home ranges of sub-adult males and a juvenile male was 2.2 km(^2), and two adult females averaged 2.5 km(^2); one adult male had a range size of 4.4 km(^2) . Kodkods did not seem disturbed by the presence of humans. Circumstantial evidence suggests that small patches of preferred habitat are not utilised if beyond a minimum threshold distance from neighbouring patches. An attempt was made to generate a crude density estimate for mountain lions and kodkods throughout their geographic ranges; and according to which mountain lion population numbers do not differ greatly from kodkods'. However, while both species seem to be adaptable to different habitats within their ranges, they seem to be affected by different pressures which affect their vulnerability status. Kodkods have a restricted geographic range and probably low dispersal capability although their high density in suitable habitats and their adaptability to exist in modified habitats possibly compensates for this. The dispersal capability of mountain lions in the southern Neotropics may be hampered because their populations are far apart due to habitat fragmentation and lack of prey as a result of hunting and persecution. Their ability to disperse through modified landscapes and adapt to changing environments may compensate this disadvantage.