Extralimital movements of reintroduced bison (Bison bison): implications for potential range expansion and human-wildlife conflict

Abstract

Extralimital movements are of interest to ecologists and wildlife managers alike because they can be used to understand the ecological process of range establishment and to determine if management interventions are necessary. I summarize available information of 17 observations of extralimital movements of 23 bison (Bison bison) from two reintroduced populations in northwestern Canada, during 2000–2016. Distances recorded from the release sites and the centre of their range were 125–260 and 70–285 km, respectively. All observations were of adult (≥5 years old) males, and most (11 of 17) were of lone animals. Most (13 of 17) observations of extralimital bison were made during summer, ≥10 years after reintroduction. Results were similar for both populations. Four extralimital bison were killed by wildlife officials because of conflicts with agricultural interests; the fate of the others was unknown. These data point to the exploratory nature of reintroduced adult male bison during the summer, which may be a precursor to range expansion. Wildlife managers can monitor extralimital movements of reintroduced bison to identify potential areas of future range expansion or human-bison conflict. More generally, these observations may be useful to inform planning efforts for future reintroductions of bison.