Breeding habitat expansion in the Grey heron (Ardea cinerea)

Predicting the response of natural populations to habitat loss and the ecol ogical consequences to communities is one of the great challenges of ecolog y. Here, we report long-term (30 years) results from an ecological survey i llustrating a change of breeding habits in the Grey heron, Ardea cinerea. C omparative data on brood size show that Grey herons adopting a new breeding behaviour produce more nestlings than other individuals in the modified ar ea. Interestingly, this recent behavioural change may result in indirect ef fects on the community structure by negatively affecting the breeding popul ation of the Purple heron Ardea purpurea. (C) 2000 Editions scientifiques e t medicales Elsevier SAS.