Exploration syndromes in the frog Xenopus (Silurana) tropicalis: correlations with morphology and performance?

Exploration behaviour is a complex trait that may have strong implications for the fitness of individuals and the persistence of populations. Understanding the different exploration strategies is necessary to understand how animals may adapt to changes in their environment including human-induced habitat fragmentation. Behavioural syndromes are often thought to characterize exploration behaviour, and within a population, individual strategies may vary from bold' to shy'. Although our understanding of behavioural syndromes has increased enormously over the past decade, little is known about the presence of such syndromes in frogs. Yet, frogs are particularly sensitive to changes in their environment because of their ectothermic physiology and low mobility. Here, we investigate the exploration behaviour of wild-caught male frogs under laboratory conditions to test whether distinct behavioural strategies exist. We demonstrate the presence of different behavioural syndromes with two of the syndromes that can be categorized as bold' and shy', and a third one that is clearly intermediate. These behavioural strategies are, however, independent of variation in morphology and locomotor performance indicating that these two components of mobility (i.e. behaviour and locomotor capacity) are decoupled and could thus respond differentially to selection on mobility.