Mutual influence of the maternal hen's food calling and feeding behavior on the behavior of her chicks.

It is widely accepted that brooding hens attract their chicks to food by food calling, but until now, the concurrent behavior of hens and chicks has never been investigated in depth. This study provides a detailed analysis of both the behavior of brooded chicks and the distance to their mother in relation to her feeding sequences, and whether they contained food calling. Our results revealed that brooding hens utter food calls while pecking, especially when their chicks are not feeding and/or have been at some distance for several seconds. Chicks' response to their mother's feeding activities was more pronounced in the presence than in the absence of food call. Chicks responded to this call by approaching their mother and increasing their pecking; their response became more efficient as they grew older. We thus consider food calls as an arousal vocalization that directs the chicks' attention to a food item chosen by a hen.