Behavioural Plasticity by Eastern Grey Kangaroos inResponse to Human Behaviour

Animals (Basel). 2019 May 15;9(5):244. doi: 10.3390/ani9050244.

Abstract

Sharing landscapes with humans is an increasingly fraught challenge for wildlife acrossthe globe. While some species benefit from humans by exploiting novel opportunities (e.g., provisionof resources or removal of competitors or predators), many wildlife experience harmful effects, eitherdirectly through persecution or indirectly through loss of habitat. Consequently, some species havebeen shown to be attracted to human presence while others avoid us. For any given populationof a single species, though, the question of whether they can recognise and change their responseto human presence depending on the type of human actions (i.e., either positive or negative) hasreceived little attention to date. In this study, we chose to examine the behavioural plasticity withina single population of eastern grey kangaroos (Macropus giganteus) to both positive and negativehuman activity. Within a relatively small and contiguous landscape, we identified areas wherekangaroos experience a combination of either low and high frequencies of benign and harmfulhuman disturbances. From six sampling sessions over five months, we found that density and groupsizes were higher where humans acted benignly towards them, and that these groups had higherrepresentations of sub-adults and juveniles than where humans had harmful intentions. Importantly,we found that the vital antipredator strategy of increasing group size with distance from cover wasnot detectable at sites with low and high levels of harm. Our findings suggest that these kangaroosare recognising and adjusting their behavioural response to humans at fine spatial scales, a plasticitytrait that may be key to the survival of these species in human dominated landscapes.

Keywords: adaptation; behavioural plasticity; eastern grey kangaroos; grouping behaviour; human behaviour; human shield; hunting.