Résumé
Predicting the response of natural populations to habitat loss and the ecological consequences to communities is one of the great challenges of ecology. Here, we report long-term (30 years) results from an ecological survey illustrating a change of breeding habits in the Grey heron, Ardea cinerea. Comparative data on brood size show that Grey herons adopting a new breeding behaviour produce more nestlings than other individuals in the modified area. Interestingly, this recent behavioural change may result in indirect effects on the community structure by negatively affecting the breeding population of the Purple heron Ardea purpurea.