Learning from the mistakes of others: How female elk (Cervus elaphus) adjust behaviour with age to avoid hunters

Abstract

In animal behaviour, there is a dichotomy between innate behaviours (e.g., temperament or personality traits) versus those behaviours shaped by learning. Innate personality traits are supposedly less evident in animals when confounded by learning acquired with experience through time. Learning might play a key role in the development and adoption of successful anti-predator strategies, and the related adaptation has the potential to make animals that are more experienced less vulnerable to predation. We carried out a study in a system involving a large herbivorous mammal, female elk, Cervus elaphus, and their primary predator, i.e., human hunters. Using fine-scale satellite telemetry relocations, we tested whether differences in behaviour depending on age were due solely to selection pressure imposed by human hunters, meaning that females that were more cautious were more likely to survive and become older. Or whether learning also was involved, meaning that females adjusted their behaviour as they aged. Our results indicated that both human selection and learning contributed to the adoption of more cautious behavioural strategies in older females. Whereas human selection of behavioural traits has been shown in our previous research, we here provide evidence of additive learning processes being responsible for shaping the behaviour of individuals in this population. Female elk are indeed almost invulnerable to human hunters when older than 9–10 y.o., confirming that experience contributes to their survival. Female elk monitored in our study showed individually changing behaviours and clear adaptation as they aged, such as reduced movement rates (decreased likelihood of encountering human hunters), and increased use of secure areas (forest and steeper terrain), especially when close to roads. We also found that elk adjusted behaviours depending on the type of threat (bow and arrow vs. rifle hunters). This fine-tuning by elk to avoid hunters, rather than just becoming more cautious during the hunting season, highlights the behavioural plasticity of this species. Selection on behavioural traits and/or behavioural shifts via learning are an important but often-ignored consequence of human exploitation of wild animals. Such information is a critical component of the effects of human exploitation of wildlife populations with implications for improving their management and conservation.

Bark Beetle‐Affected Forests Provide Elk Only a Marginal Refuge from Hunters

“…Relative to summer (recreation use in our study area was minimal during the summer relative to during the hunting season), elk gradually shifted their patterns of habitat selection to include more cover (i.e., beetle‐infected and non‐infected forested areas) and less grass meadows during the hunting seasons, which is consistent with studies demonstrating that some ungulates use cover disproportionately to its availability (Irwin and Peek , Leckenby , Paton et al ) and seek cover during the hunting season to increase survival (Ciuti et al , Lone et al , Thurfjell et al ). Somewhat counter to our findings, however, Proffitt et al () did not report a strong relationship between elk use of forested areas while elk were under the threat of hunting.…”

“…Although it may be subtle, these results suggest there may be a benefit to elk by using beetle‐kill over intact green conifer when hunting pressure is high (i.e., reduced predation risk or access to other resources; Hernández and Laundré , Bonnot et al ). We suspect elk use of beetle‐kill may offer a perceived refuge (Mysterud and Østbye , Thurfjell et al ) while simultaneously increase foraging opportunities (Pec et al ), which may thus reduce the tradeoff associated with seeking refuge at the cost of access to forage. Although recent researchers in the same study area did not report that increases in understory in beetle‐kill resulted in increased use of these areas by elk (Lamont et al ), this work was explicitly focused on summer (Jun–Aug), and it may be that when elk are faced with hunting pressure they use this novel forage resource while attempting to reduce exposure to hunters (Lone et al ).…”

Safety first: seasonal and diel habitat selection patterns by red deer in a contrasted landscape

“…In this regard, it is noteworthy that all 16 individuals tracked in this study survived the 2006–2007 hunting season. It would be worthwhile gathering data of individuals that actually got shot to understand if they differed in their behaviour and habitat selection patterns (Bonnot et al ., ), and somewhat failed to optimize the forage‐safety trade‐off (Lone et al ., ; Thurfjell, Ciuti & Boyce, ). Due to limited sample size, we could not meaningfully test for sexual differences in habitat selection either.…”

Use, selection, and home range properties: complex patterns of individual habitat utilization

“…, Thurfjell et al. ). We found large individual variation in habitat selection ratios in moose, of which only a small proportion was explained by sex, age and season.…”