Winter behaviour of the Ya Ha Tinda (YHT) elk herd near Banff National Park (BNP) in Alberta

Maddie Trottier’s research focused on winter behaviour of the Ya Ha Tinda (YHT) elk herd near Banff National Park (BNP) in Alberta. Historically, 90% of the elk migrated westward to summer in BNP; now, 65% of the elk have become residents of the winter range year-long. Despite more favourable summer range conditions, differences in habitat use and foraging behaviour on the sympatric winter range may affect the decline in western migrants. Human-habituated resident elk use YHT ranch infrastructure as a predator refuge to reduce foraging costs of vigilance and form larger groups than western migrants, contributing to their success. Recently, a new migratory segment has emerged with ~60% of the elk that migrate moving east to summer on low-elevation, industrial timber lands. The differences in behaviour of these eastern migrants compared to residents and western migrants is not well understood, and may explain the recent success of this herd segment. The purpose of this study is to contrast the behavioural differences of the three migratory herd segments on their sympatric winter range, which may affect survival. Using field observations and GPS collar locations from tagged female elk, Maddie studied habitat use, vigilance patterns, and group behaviour of the three different herd segments to address 3 hypotheses: 1) eastern migrants are excluded by residents to poor quality habitat in winter, 2) residents will have larger, more cohesive winter groups, and show less foraging interference than migrants. 3) Migrant elk show more vigilance for predators and humans than resident elk with a subsequent foraging cost as a trade-off. Focusing on these three migratory segments will further our understanding of how migration influences elk behaviour and affects overall population trends.