Behavioural plasticity - determining the adaptive significance of parental care.

Parental care is a widespread phenomenon among the animal kingdom. It increases offspring survival, but entails fitness costs for the parents too. The resulting trade-off between investing in current offspring or in self-maintenance is a central tenet of life-history theory. But the costs and benefits of any parental decision will not be constant, but vary with multiple environmental factors. When adjusting their level of investment, parents therefore respond to cues from their ecological and social environment. Phenotypic plasticity, the ability of an individual to alter trait expression in function of the environment, plays logically a central role during parental care. However, the ability to respond may under some circumstances be confounded. Individuals may for example differ in their foraging specialization, which impinges on their flexibility in parenting via an interdependence of behavioral consistency across different traits ("personality"). Moreover, the optimal parental decision will not only depend on the individual itself, but also on (its response to) the contribution to care by its partner. Parental responsiveness during this reciprocal interplay is thus likely to affect the efficiency of cooperation within pairs, and ultimately reproductive success. The reciprocal interplay in the debate over care, however, makes the coadaptation of corresponding traits possible (via indirect genetic effects), as has been shown in the context of parent-offspring communication. Such coadaptation may in turn impose limitations on the expression and evolution of individual behavioral traits - representing another important component for our understanding of the evolutionary ecology and stability of parental care. This multidimensional complexity of parental care is fascinating and highly relevant, given the importance of parental care for the expression and development of ecologically important traits. It can best be studied by applying the recently developed behavioral reaction norm concept, which allows to partition phenotypic variance and to subsequently identify the adaptive significance of individual differences in (behavioral) variance components.

Keywords:EXPERIMENTAL STUDY, ECOSYSTEM FUNCTION, NATURAL SELECTION

Disciplines:Animal biology, Veterinary medicine