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Studies of wildlife have shown consistent individual variation in behavioural plasticity, which affects the rate of adaptation to changing environments. More flexible individuals may thus be more prone to habituation and conflict behaviour, but these applications of personality to wildlife management are little explored. Behavioural lateralization reflects cerebral specialization that may predict diverse expressions of behavioural plasticity. We recorded front-limb biases (i.e. handedness) in wild elk (Cervus canadensis), a species with facultative migration and high rates of habituation inside protected areas. Less lateralized elk responded more strongly to the application of aversive conditioning (predator-resembling chases by humans) by increasing their average flight response distances, but these same animals were also quicker to reduce their flight responses (i.e. habituate) when human approaches were benign. Greater laterality was correlated with, but not completely predicted by, bolder personalities, which we quantified via five correlated behavioural metrics. Lastly, lateralized elk were three times more likely to migrate, whereas less lateralized animals were similarly likely to remain near humans year-round. Lateralized behaviours can provide insight into behavioural flexibility enabling certain individuals to more quickly adapt to human-disturbed landscapes, and offer an especially productive arena for collaborative work by behaviourists, conservation biologists and wildlife managers.

Ungulate species around the world are habituating to humans and human infrastructure, which can cause the loss of migratory behavior, local overpopulation, ecosystem damage, and human-wildlife interactions. Wildlife managers sometimes attempt to reduce habituation by subjecting ungulates to aversive conditioning, comprised of negative stimuli in association with specific locations or behaviors, but high variability in the responsiveness of animals has limited the utility of this technique. We studied this limitation using 20 wild elk (Cervus canadensis) inhabiting a mountain town by identifying and comparing the responses of individuals categorized along a personality gradient from shy to bold, subjecting animals to aversive conditioning that either isolated animals or let them remain in a group, and then comparing their wariness via flight response distances before, during, and after conditioning. Bolder elk had significantly greater increases in wariness during conditioning and greater decreases in wariness once the conditioning period was complete. Isolation versus group-based treatment did not affect responsiveness during the conditioning period, but isolated animals retained more wariness after conditioning ended. These results suggest that wildlife managers could increase the efficacy of aversive conditioning by identifying and targeting specific personality types and individuals to modify behavior and mitigate the broader ecological effects of habituated wildlife.

Loss of migratory behavior in ungulates often occurs with habituation to people to cause several challenges for wildlife managers, particularly in protected and urban areas. Aversive conditioning to increase ungulate wariness toward people could be an important tool for managing wildlife conflicts, but it is frequently thwarted by variation in responsiveness among individuals, an aspect of personality that is currently little understood by managers. In our paper, we describe the potential role of personality in the ecological progression associated with habituation, loss of migration, and human-wildlife conflict in ungulates. We do so by (a) synthesizing our prior work on two populations of wild elk (Cervus canadensis) living in national parks in the Canadian Rocky Mountains, (b) using it to articulate a conceptual model to explain how anthropogenic changes in landscapes favor bolder individuals, and (c) showing how targeted use of aversive conditioning could limit the advantages to bold individuals that promote residency. Our review showed how bolder elk, defined by a combination of seven separate personality metrics on a bold-shy continuum, are three times more likely to forego migration, but are also quicker to learn by association, whether via the provision or cessation of aversive conditioning. Differences in personality may relate to cognitive flexibility, which we measured with limb use preferences, to imbue bolder elk with more rapid responses to changing environments. In our conceptual model, we show how four ecological drivers comprised by interactions with humans, predators and conspecifics, in addition to changes in forage, favor bolder elk that are more likely to adopt a resident migratory tactic. We also explain how bold personalities could result from behavioral flexibility, genetic differences, or gene-environment interactions, each of which could be moderated by frequency-dependent payoffs to individuals. We suggest that managers could limit the prevalence of bold, resident ungulates by targeting bolder individuals with active and specific aversive conditioning, while minimizing anthropogenic food sources in predator refugia. A better understanding of personality in wildlife could support more proactive strategies to limit habituation and encourage migration and other keystone behaviors in changing landscapes.

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