Auditory laterality in a nocturnal, fossorial marsupial (Lasiorhinus latifrons) in response to bilateral stimuli

Abstract

Behavioural lateralisation is evident across most animal taxa, although few marsupial and no fossorial species have been studied. Twelve wombats (Lasiorhinus latifrons) were bilaterally presented with eight sounds from different contexts (threat, neutral, food) to test for auditory laterality. Head turns were recorded prior to and immediately following sound presentation. Behaviour was recorded for 150 seconds after presentation. Although sound differentiation was evident by the amount of exploration, vigilance, and grooming performed after different sound types, this did not result in different patterns of head turn direction. Similarly, left–right proportions of head turns, walking events, and food approaches in the post-sound period were comparable across sound types. A comparison of head turns performed before and after sound showed a significant change in turn direction (χ2 1=10.65, p=.001) from a left preference during the pre-sound period (mean 58% left head turns, CI 49–66%) to a right preference in the post-sound (mean 43% left head turns, CI 40–45%). This provides evidence of a right auditory bias in response to the presentation of the sound. This study therefore demonstrates that laterality is evident in southern hairy-nosed wombats in response to a sound stimulus, although side biases were not altered by sounds of varying context.