Personality influences habituation behaviour in ungulates

The habituation of wildlife to humans is a growing global problem that damages ecological integrity and threatens public safety, but the behavioural processes underlying habituation have rarely been explicitly tested in large animals. These processes are also likely influenced by animal personality. I used three personality traits to delineate a gradient of shy to bold personality types in captive elk (Cervus canadensis). I then attempted to habituate elk using either food attractants paired with inactive human presence, or with human approaches but no food attractants. Both food and approach treatments significantly reduced elk wariness, as measured by mean flight response distances, while elk in a control pen showed no change. During approach treatments bolder elk showed significantly larger reductions in wariness than shyer elk, but personality had no influence on wariness reductions after food conditioning. My results demonstrate that habituation can be proactive, whereby animals overcome wariness as a way to reap rewards, but can also be reactive, whereby animals can be forced to habituate through the repeated exposure to negative stimuli to which wariness responses are energetically costly. I showed that changes in optimality decisions surrounding risk and reward are influenced by the personalities of individual animals.