Dispersal of Juvenile Cougars in Fragmented Habitat

Abstract

There is little information on the spatiotemporal pattern of dispersal of juvenile cougars (Felis concolor) and no data on disperser use of habitat corridors. I investigated dispersal of radio-tagged juvenile cougars (8 M, 1 F) in a California landscape containing 3 corridors (1.5, 4.0, and 6.0 km long) and several habitat peninsulas created by urban growth. Dispersal was usually initiated by the mother abandoning the cub near an edge of her home range. The cub stayed within 300 m of that site for 13-19 days and then dispersed in the direction opposite that taken by the mother. Mean age at dispersal was 18 months (range 13-21 months). Each disperser traveled from its natal range to the farthest part of the urban-wildland edge, Dispersing males occupied a series of small (<30% the area used by ad M in the same time span), temporary (10-298 days) home ranges, usually near the urban-wildland interface, and often with its longest border along that edge. Each of the 3 corridors was used by 1-3 dispersers, 5 of the 9 dispersers found and successfully used corridors, and 2 dispersers entered but failed to traverse corridors. Dispersing cougars will use corridors that are located along natural travel routes, have ample windy cover, include an underpass integrated with roadside fencing at high-speed road crossings, lack artificial outdoor lighting, and have <1 dwelling unit/ 16 ha