Age and spatial behavior determine survival of male elk during the hunting season

Abstract Understanding factors that influence the vulnerability of wild animals to harvest is of interest to wildlife managers as they strive to implement management strategies that achieve population and distribution objectives. Growing evidence suggests that ungulates adjust their behavior to mitigate harvest risk, such as decreasing their rate of movement and selecting habitat indicative of security to lessen detectability. However, few studies have evaluated how behavior that might mitigate harvest risk interacts with age and influences survival. We used 4 years of movement, age, and survival data from 61 adult male elk ( Cervus canadensis ) in west‐central Montana, USA, to test 2 hypotheses: 1) age influences elk behavior amid hunting pressure, and 2) age and behavior interact to influence elk survival during the hunting season. Consistent with our predictions, elk used and selected security attributes, including areas at high elevation and far from motorized routes, but contrary to expectations, elk avoided dense forest on land with public access. Behavior to mitigate risk varied among individual elk and was influenced by age. Young, inexperienced elk (<4 years old) and mature, experienced elk (>7 years old) moved less, used higher elevations, steeper slopes, denser cover, and selected more strongly for land with public access compared with middle‐aged elk (4–7 years old). Both age and behavior influenced vulnerability and likelihood of harvest. At the beginning of the hunting season, odds of survival increased by 40% with every 1‐year increase in age, but by the end of the hunting season, survival was similar across all age classes. Moreover, male elk were 52% more likely to survive the hunting season when time spent on land with restricted access increased from 0% to 100%. Our findings suggest that elk of varying ages employ flexible strategies to mitigate harvest risk and highlight the behavioral and demographic mechanisms that elicit use of security attributes during a period of heightened risk.