Home Ranges and Spatial Organization of Fishers, Martes pennanti, in Central British Columbia

We described the size and spatial arrangement of aggregate and seasonal home ranges for 17 radio-tagged resident Fishers (Martes pennanti) that were >1.5 years old in two areas of central British Columbia during 1990-1993 and 1996-2000. We estimated home range size for each Fisher from the 95% isopleth of the utilization distribution generated using a fixed kernel model with smoothing selected by least-squares cross-validation (95% FK). For comparison to previous studies, we also calculated the minimum convex polygon estimate of home range size (MCP) for each animal. The aggregate home ranges (95% FK) of female Fishers (mean = 37.9 km², SD = 18.5, range = 10.5 – 81.2, n = 11) were significantly smaller than those of males (mean = 161.3 km², SD = 100.0, range = 46.0 – 225.2, n = 3; P = 0.019). We observed minor overlap among 95% FK home ranges of Fishers of the same sex, but considerable overlap among home ranges of males and females. Home ranges (95% FK or MCP) that we observed in central British Columbia were larger than those reported elsewhere in North America, particularly for males. We suggest that the distribution of resources for Fishers may occur at lower gross densitiesin central British Columbia than in other portions of the Fisher’s range and that suitable habitat in which Fishers can establish home ranges is not found uniformly across the landscape

Seasonal movements of black-tailed deer on northern Vancouver Island

Columbian black-tailed deer (Qdocoileus hemionug cplumbianus Richardson) were radio-tagged in a deep snowfall region on northern Vancouver Island, British Columbia. These deer were monitored to determine seasonal movements and habitat use. Deer exhibited either resident or migratory movement patterns. Resident deer made seasonal shifts in their home range centres but their seasonal home ranges overlapped. In migratory deer, summer home ranges were separated from both spring and winter home ranges, although their spring and winter home ranges overlapped. Altitudinal migrations occurred by deer moving between high and low elevation habitats. Horizontal migrations occurred by deer moving between a small tributary valley and the main valley. Seasonal movements of black-tailed deer result from habitat selection by deer seasonally moving to more favourable habitats as determined by more available energy and nutrients, and lower risk of predation. The causal differences between vertical and horizontal migrations as well as seasonal shifts in home range centres can be resolved by a model of habitat selection based on these factors. The densities of available digestible dry matter in Amabilis Fir - Twisted Stalk, and Mountain Hemlock - Copperbush associations are comparable with those in the shrub and conifer serai stages. This abundance of deer food in high elevation habitats suggests that forest harvesting in high elevations will not affect deer populations, if their other habitat requirements are met. In areas where forested summer ranges already exist, low elevation logging of Sword Fern - Western Red Cedar, Deer Fern - Western Hemlock, and Western Hemlock - Plagiothecium associations will provide deer with sources of abundant food closer to their winter ranges than the high elevation summer ranges. Use of these food sources may result in only a redistribution and not an increase in the deer population. Logging of Amabilis Fir - Western Hemlock, Salal - Douglas-fir, and Salal - Western Hemlock associations may be detrimental to deer populations because of their need for these habitats during winter. Management policies emphasizing preservation of severe winter range could be detrimental to deer populations. Habitat management for black-tailed deer must include provision of mild winter range as well as severe winter range. Because mild winter range provides deer with greater amounts of available energy and nutrients, it may be as important to the over-winter survival of deer as is severe winter range. The mobility of black-tailed deer and their sensitivity to snow suggest that few deer would be trapped in high elevations by early snowfalls. Corridors joining high and low elevations appear unnecessary to facilitate deer migrations.Forestry, Faculty ofGraduat

Social behaviour in a non-pupping colony of steller sea-lion (Eumetopias jubata)

Eumetopias jubata is polygyncus. The sea-lions segregate during the breeding season into pupping colonies consisting of adult males and females, and non-pupping colonies consisting mainly of sub-adult males. All previous studies of the social behaviour E. jubata have been concerned only with pupping colonies. This study describes the social behaviour and organization of a non-pupping colony. The colony is located at Mclnnes Island, British Columbia (Lat. 52°16’ N., Long. 128°43’ W.). It consists of 100-150 animals. They are mainly sub-adult males though several adult sea-lions of both sexes were present. Data concerning six age-sex classes were taken using two methods. One method involved the development of an ethogram consisting of 34 behaviour patterns and the observation of social interactions. The other method involved spacial organization and activity. Qualitative notes on territorial and reproductive behaviour as well as population structure were also recorded. A peck-dominance hierarchy exists between the classes and is related to many of the behaviours measured. Males are more socially involved than females. This is more voluntary for males than it is for females. As males mature their behaviour becomes more complex than that of females. Females are not aggressive. This is reflected by their lack of Body Contact behaviour. Males are aggressive towards other males and use more Body Contact behaviour than females. Body Contact behaviour is mainly physical aggressive interaction. As males mature it is replaced with Non-body Contact behaviour which is largely threats and displays. The intense social conditioning of sub-adult males results in more socially adept adults that are better able to cope with the complex society at pupping colonies. Sub-adult males are not territorial. However, some adult males are. This is related to the presence of females. Territories act as refuges for females who avoid areas of activity and harassment by sexually mature sub-adult males. This contributes to the grouping of females around territorial adult males. Non-pupping colonies are spatially organized similar to pupping colonies except for the relative proportion of age-sex classes. Socially, non-pupping colonies are less organized than pupping colonies. Social organization in E. jubata is promoted by the tranquil behaviour of adults and inhibited by the disruptive behaviour of sub-adult males.Science, Faculty ofZoology, Department ofGraduat

Cannibalism by black bears in the Nimpkish Valley, British Columbia

Cannibalism by black bears in the Nimpkish Valley, British Columbi