Topography affects foot trembling side preference in the North Island robin (Petroica longipes)

Behavioural laterality, where an individual shows a preference for using its left or right side when engaging in a task, has been documented in a wide range of species. Typically, such preferences have been correlated with neurological biases associated with brain structure, genetics, sex, and age. In birds, behavioural laterality (and footedness) is most commonly expressed in the searching and handling of food. I examined foot preferences during foraging in the North Island robin (Petroica longipes), a species which rapidly vibrates one of its legs when searching for food on the forest floor. Topography of the study site had a significant effect on the laterality of the individual, with the uppermost leg almost exclusively used for the trembling behaviour. With this exception, there was no bias in which leg was used across the population or within the individual for different sexes or age classes. As study sites and their features are seldom described in laterality studies, the results of my study show that topographical features may be important factors in determining side preferences and need to be accounted for.