Behavioural flexibility in anuran amphibians

Studies on behavioural flexibility in animals have largely focussed on higher vertebrates, i.e. mammals, birds and fish. Amphibians have traditionally been assumed to be highly instinct-bound with highly stereotyped behaviour. Due to the lack of research in this field, little is known about cognitive processes in amphibians, such as strategic planning and behavioural flexibility. The general aim of the proposed project is to investigate mechanisms of behavioural flexibility in anuran amphibians. I plan to perform a set of field and laboratory experiments on two anuran model species. Comparing the results to findings in other taxa will provide important insights into the evolution of behavioural plasticity in parental care and sexual selection, not only in anuran amphibians but also in vertebrates in general. Poison frogs (Dendrobatidae) show a remarkable diversity of parental behaviour and recent research has demonstrated the presence of behavioural plasticity in tadpole deposition strategies for several dendrobatid species. The dendrobatid frog Allobates femoralis is widely used as a model organism for research on behaviour, population genetics, ecology and evolution. Observations in the field and preliminary experiments in the lab indicate that A. femoralis females show behavioural plasticity with respect to tadpole transport. Although tadpole transport is performed almost exclusively by males, females flexibly take over parental duties in the event of male absence. In contrast, A. femoralis males probably exhibit a fixed action pattern with regard to tadpole transport, transporting all clutches within their territorial boundaries, regardless of whether they are their genetic fathers. In the proposed project I shall investigate the mechanisms that trigger female parental behaviour, e.g. acoustic or spatial properties of the male advertisement call. The work will provide the first evidence for spontaneous behavioural flexibility in a uni-parental species with generally fixed sex-specific parental roles. One of the fundamental prerequisites of behavioural plasticity is the ability to perceive, identify and respond to changes in the environment. Studies in mammals including humans have assigned specific regions in the brain to stereotyped and highly flexible behaviours and have shown that differential activation potentials are elicited in the associated areas of the brain. I plan to perform functional magnetic resonance imaging (fMRI) using a manganese-enhanced protocol to localize and quantitatively map differences in metabolic brain activity when processing familiar and novel (acoustic and visual) stimuli in the Northern Leopard Frog Rana (Lithobates) pipiens. This will be the first functional brain imaging study on an amphibian species and will investigate for the first time the representation of a novel stimulus in a non-primate vertebrate. As amphibians are considered to be the most basal vertebrate group, my findings will provide important implications on the neuronal structures required for the evolution of flexible behaviour.

No additional funding sources recorded.