Data for: Living in fear: How experience shapes caribou responses to predation risk

Wild prey can reduce predation risk by avoiding areas used by their
predators. As they get older, individuals should be able to fine-tune this
avoidance based on their increased experience with predators and cues
associated with predation risk. Such learning mechanisms are expected to
play a key role in how individuals may cope with risk during their life,
particularly in altered landscapes where human disturbances have created
habitat conditions distinct from those of the past. We studied the role of
experience on the avoidance of risky areas by boreal caribou (Rangifer
tarandus caribou) in a system where they are under high predation pressure
from grey wolves (Canis lupus) and black bears (Ursus americanus). We
described the behavioural responses of caribou to variations in the risk
of encountering wolves and bears, investigating whether individuals
adjusted their level of predator avoidance with passing monitoring years,
a proxy of increasing experience. We used telemetry data collected on 31
wolves and 12 bears to map spatial variations in the risk of encountering
predators. We used data from 28 collared female caribou monitored for 3–8
years (mean ± SD: 4.4 ± 2.2) to assess trends in the avoidance of risky
areas by caribou with passing years. We observed an increase in the
avoidance of areas suitable to wolves with passing years, except during
winter and calving when females did not adjust their avoidance of wolves.
We also found an increase in the avoidance of areas suitable to bears
across all study periods. These results suggest that, in most
circumstances, caribou became more efficient at avoiding areas selected by
their main predators as they gained experience throughout their life.
Provided the avoidance tactics observed in this study are heritable and
offer fitness advantages to the individuals that display them, our results
suggest that caribou populations living in disturbed environments may have
the potential to adapt to changing predation risk. Our findings have
encouraging implications for caribou and wildlife conservation in general,
as they suggest that experience may allow prey to adjust to novel
conditions, including higher predation risk.