Social and spatial organization of Vancouver Island cougar (Puma concolor vancouverensis, Nelson and Goldman, 1943)

• Main Author: Hahn, Apryl M.
• Format: Others
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/12089

Vancouver Island is noted for having the highest concentration of cougar-human interaction in North America, yet prior to this study, little scientific data were available on the only subspecies of cougar to occur on Vancouver Island. I studied a cougar (Puma concolor vancouverensis) population in coastal temperate rainforests on southeastern Vancouver Island, British Columbia. Initiated in 1991 and conducted during 1993 - 1996, my study examined home range characteristics, dispersal, recruitment, population structure and density. Mean size (61 km) of annual home ranges of female cougar was as small or smaller than reported in other studies. Male home ranges were exclusive and overlapped several resident females, a social structure that is typical of most studied populations. Dispersal of young was male-biased in my study with all young males dispersing from the study area and included the first scientifically documented occurrence of a cougar swimming from Vancouver Island to adjacent Gulf Islands. In contrast, all known female offspring remained within the study area and provided the only identified source of recruitment into the resident female population. Subadult females displayed 100% philopatry establishing home ranges that overlapped or were immediately adjacent to their natal home range. Recruitment of female offspring continued irrespective of increasing density in the final 2 years of the study. Cougar densities (5.0 /100 km²), documented in the final year of the study, were among the highest recorded densities in North America. Observed densities were characterized by small home ranges with considerable home range overlap among resident female cougar. Indices of deer abundance were insufficient to explain the high density of cougar or small size of home ranges. Only 2 types of mortality were identified in this population. Animal control kills contributed most (58%) to cougar mortalities and was likely attributable to the close proximity of the study to human populated areas. Intraspecific killing accounted for 80% of remaining mortality or 33% of total mortalities. The high density and level of intraspecific strife observed in this cougar population are characteristic of a population regulated by social interactions and may suggest that social interactions were a regulatory factor in my study population. === Land and Food Systems, Faculty of === Graduate