Rice fields support a large portion of herons breeding in the Mediterranean Region

The importance of rice fields for breeding herons was assessed during comparative studies of their foraging ecology (densities of foraging adults, prey abundance, feeding success, chick diets) in the five major regions of rice cultivation in Europe: northwest Italy, the Po Delta in northeast Italy, the Rhone Delta in France, the Axios Delta in Greece, and the Ebro Delta in Spain. Rice fields offered better conditions to foraging herons than natural habitats in northwestern and northeastern Italy where the number of feeding herons, food intake rates, and prey abundance in rice fields were higher. The proportion of the food resources obtained by herons from the agricultural habitats, rice fields and small irrigation canals was estimated using two independent methods. Six heron species acquired more than half of their food from rice fields in all the regions except the Rhone Delta where agricultural habitats offered less prey. We conclude that rice fields are the main foraging habitat for herons breeding in Mediterranean Europe, and we urge authorities to consider the special importance of rice field management to the conservation of Mediterranean herons.