Risk‐taking in free‐living spotted hyenas is associated with anthropogenic disturbance, predicts survivorship, and is consistent across experimental contexts

Abstract

Anthropogenic disturbance can have important influences on the fitness and behaviors of wild animals, including their boldness when exposed to risky conditions. We presented spotted hyenas (Crocuta crocuta) from two populations, each exposed to a different level of human activity, with a life‐size model hyena representing an intruder from another clan. The high‐disturbance population lived adjacent to human settlements, and the low‐disturbance population inhabited a relatively undisturbed part of the same national park in Kenya. The mock intruder was presented to individual hyenas to assess their reactions to an alien hyena, and to determine whether their reactions varied with their exposure to anthropogenic activity. We found that human disturbance was indeed associated with hyena risk‐taking behavior in response to the model intruder. Hyenas tested in the low‐disturbance area exhibited more risk‐taking behaviors by approaching the mock intruder more closely, and spending more time near it, than did their counterparts living in high‐disturbance areas. Hyenas that spent less time in close proximity to the model had greater survivorship than those that spent more time in close proximity to it, regardless of disturbance level. Furthermore, the individual differences in risk‐taking measured here were consistent with those obtained previously from the same animals using a different set of experimental manipulations. However, the experimentally induced behaviors were not consistent with naturally occurring risk‐taking behaviors in proximity to lions; this suggests that risk‐taking behaviors are consistent within individuals across experimental contexts, but that exposure to lions elicits different responses. Although our results are consistent with those from earlier tests of anthropogenic disturbance and boldness in spotted hyenas and other predators, they differ from results obtained from birds and small mammals, which are generally found to be bolder in areas characterized by human disturbance.

Fitness Consequences of Innovation in Spotted Hyenas

“…Hyenas that are bolder in the presence of lions, in particular, have a higher risk of mortality than conspecifics with intermediate or low levels of boldness (Yoshida et al, 2016), so lower survivorship among offspring of innovative females may be mediated by high boldness during conflict or competition with lions. In addition, greater risk-taking behavior in spotted hyenas, measured with a "mock intruder" test, is also correlated with a higher risk of mortality (Turner et al, 2019). Overall, if more proactive, bold, or risk-taking behavior, demonstrated by hyenas while interacting with problem-solving apparatuses, is correlated with their behavior in other contexts, it is possible that these traits mediate the link between innovation and survival.…”

A World for Reactive Phenotypes

“…For instance, when comparing the behavior of predatory fishes living in relatively unprotected areas (recreational fishing permitted) to old notake kelp forests (that have been protected for 40 years), some species are 6.5 times less bold toward prey (as quantified by the number of attacks) and consequentially consume nearly half the prey compared to those in fully protected areas (Rhoades et al, 2019). Spotted hyenas (Crocuta crocuta) inhabiting highly disturbed areas (close to humans) are less bold toward a mock intruder, compared to those living in undisturbed areas (Turner et al, 2020). As a consequence, shyer hyaenas had higher survival rates (Turner et al, 2020).…”

“…Spotted hyenas (Crocuta crocuta) inhabiting highly disturbed areas (close to humans) are less bold toward a mock intruder, compared to those living in undisturbed areas (Turner et al, 2020). As a consequence, shyer hyaenas had higher survival rates (Turner et al, 2020). Taken together, these examples illustrate how the vanishing of proactive phenotypes due to human presence or harvesting could have profound impacts on predatory-prey dynamics.…”

Dynamic table‐visiting behavior of birds at outdoor restaurants and cafés

“…Anthropogenic disturbance is increasingly being documented as a pervasive phenomenon influencing the behavior and ecology of many kinds of animals (Cayuela et al., 2020; Firebaugh & Haynes, 2016; Li et al., 2016; Tambling et al, 2015; Turner et al., 2019; Wilson et al., 2020). One mechanism, increased fear of humans by wildlife, impacts a multitude of different species, directly and indirectly, in many different ecological communities and landscapes (e.g., Berger, 2007; Clinchy et al., 2016; Leighton et al., 2010; Magle et al., 2014; Miller & Schmitz, 2019; Rösner et al., 2014).…”