Influence of body mass and environmental conditions on winter mortality risk of a northern ungulate: Evidence for a late-winter survival bottleneck.

摘要: A relationship between winter weather and survival of northern ungulates has long been established, yet the possible roles biological (e.g., nutritional status) environmental weather) conditions make it important to determine which potential limiting factors are most influential.Our objective was examine effects individual (body mass age) extrinsic (winter severity snowmelt conditions) on magnitude timing mortality for adult (>2.5 years old) female white-tailed deer (Odocoileus virginianus [Zimmerman, 1780]) during February-May in Upper Peninsula Michigan, USA.One hundred fifty were captured monitored 2009-2015 two areas with varying snowfall. ranged from 0.24 0.89 (mean = 0.69) across years. Mortality risk increased 1.9% each unit increase cumulative index, decreased 8.2% snow-free day, 4.3% kg body mass. Age weekly snow depth did not influence survival. Predation, primarily coyote (Canis latrans [Say, 1823]) wolves lupus [L., 1758]), accounted 78% known-cause mortalities.Our results suggest that severity, possibly a lesser degree condition entering winter, impacted However, spring appeared be influential factor determining late-winter our study. This supports hypothesis nutrition energetic demands both ungulate ecology. Under this model, delay several weeks could exert large survival, resulting bottleneck.