The frog Dermatonotus muelleri (Boettger 1885) (Anura Microhylidae) shifts its search tactics in response to two different prey distributions

Abstract

Search tactics are cognitive processes that organisms use to elicit a group of related and sequential behaviours that allow them to locate available resources. Some species can modify their search tactics according to different ecological conditions, such as abundance and distribution of prey. In this study, we investigate the mechanisms that elicit this shift in search tactics using the frog D. muelleri as the subject of a laboratory experiment. The shift in search tactics was measured by differences in the rate of the exploratory behaviours during the foraging activity. Under experimental conditions, D. muelleri alternates from sit-and-wait foraging when foraging within a patch, to widely foraging when locating prey aggregations. The same behavioural response has also been observed in other animal groups (fishes and invertebrates), elicited by two ecological conditions, a shift in prey spatial distribution and a shift in prey abundance through time. In general, when habitat components vary in time, causing temporal fluctuations in prey abundance, the predator evolves flexible search tactics mediated by prey density. On the other hand, if these components vary in space resulting in patchy distribution of the prey, the predators evolve search tactics mediated by the resource's spatial distribution. Therefore, both temporal instability (e.g. temporal fluctuations in prey density) and environmental heterogeneity (e.g. patch distribution of the food resource) favour the appearance of flexible search tactics.