Social versus exploration and foraging motivation in young red junglefowl ( Gallus gallus) and White Leghorn layers

Abstract

Social coherence tendency is an important behavioural characteristic in young fowl related to an underlying social motivation that can be modified by breeding. Our aim was to investigate if selection for productive traits in a certain White Leghorn layer strain has influenced different components of social motivation compared to the ancestor, red junglefowl. From both breeds, 29 chicks were tested between 4 and 7 weeks of age in four behavioural tests designed to study social motivation. A runway test was used to measure social reinstatement behaviour. Social coherence tendency versus foraging motivation was measured in both novel and familiar environments following 0 and 3 h food deprivation. The novel environment was an L-shaped social versus foraging arena and the familiar environment was identical to the chicks’ home pens. Both included stimulus birds in a box and food at opposite ends of the test arenas. Furthermore, spacing behaviour of groups consisting of three chicks was observed in a novel pen. The runway test revealed a stronger social affiliation in junglefowl when the social contact had first been reinstated. In the social versus foraging arena, junglefowl moved more whereas Leghorns spent more time immobile. These differences were greater with 3 h food deprivation. Deprivation and breed had a significant interaction resulting in more time spent feeding by junglefowl but not by Leghorns. Contrary to this, in the familiar pen, Leghorns responded to deprivation by feeding more and keeping longer distance to the stimulus birds than junglefowl. In the novel pen, Leghorn chicks had shorter nearest neighbour distances than junglefowl. The results indicate that the adaptability of the birds to their social and physical environment may have been influenced by means of selection for increased production capacity. Leghorns from the studied strain may have greater problems in adapting to a new environment.