No abstract

Capture and handling of wildlife is often an important component of studies where detailed demographic, behavioral, physiological, or health data are required. Yet, capturing and handling wildlife is sometimes controversial and lacking public support because of concern about effects on individuals. Investigating potential effects of capturing wildlife is also important to inform data-censoring protocols when using information obtained from captured animals. We investigated the short-term effect of helicopter-based capture and handling on movements of free-ranging bison (Bison bison) that were chemically immobilized in Yukon, Canada. We examined daily movement rates, home range size, and displacement of global positioning system-collared individuals immediately after capture and for 20 days thereafter. Our results indicate that there is a minimal short-term effect of helicopter-based capture on bison movements. Significant differences from apparent pre-capture movement behavior were observed only within 24 hours after capture. We observed variation among individuals, however, with some animals taking up to 10 days to return to apparent pre-capture movement rates, whereas others had no measurable response to capture. Despite individual variation, >80% of individuals had returned to apparent pre-capture movement behavior within the first 5 days after capture. Furthermore, sex-based effects were evident: females increased their daily movement rates, home range size, and displacement after capture, whereas males had either no effect or decreased movement rates. Our results suggest that movement rates are altered for only a short period after capture and, therefore, should not have severe negative effects on bison using our protocols. Accordingly, researchers should censor the first 10 days after capture from their analyses to avoid using biased information. Our study should also help inform public discourse regarding capturing and handling wildlife for research or management purposes. Ó

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Context Wolverines (Gulo gulo) are harvested for fur in northern Canada; however, the impacts of harvest are poorly known. Additionally, wolverine population data are largely absent for much of their northern range. Demographic data collected from harvested wolverines provide information on the vulnerability and variability of different sex and age cohorts to harvest, which, in turn, may have implications for harvest sustainability. Aims We examined the temporal variability of different sex and age cohorts in wolverine harvest among years, and within the harvest season, in Yukon, Canada. We also examined the pregnancy status of female wolverines in relation to the harvest date, so as to evaluate the impact of the harvest-season length on breeding wolverines. Methods We determined the sex and age composition of harvested wolverines via dissections of 655 carcasses collected from 2005 to 2014. We determined the reproductive status and fetal measurements for female wolverines via dissections of reproductive tracts. Key results The harvest consisted mostly of males, particularly of young individuals. The sex ratio of harvested animals did not fluctuate significantly, but we observed variation in the age structure among years. The age structure varied within the harvest season (November to March), with a greater proportion of adults being harvested in late winter. Active gestation was evident in females harvested after mid-January, and near-term or postpartum females were harvested during late February and March. Conclusions Late winter harvest is likely to have a more significant impact on populations than is early winter harvest, because of increased harvest of adults and breeding females. Wolverine harvest season extends to the onset of the denning season in late February and March, indicating a concern for ethical harvest. Implications Limiting the legal harvest season to early winter may contribute to improved harvest sustainability and protection of breeding wolverines in northern latitudes.