Visually imprinted maternal preference in ducklings is redirected by social interaction with siblings

This study examined the influence of social interaction with broodmates on a visually imprinted maternal preference in domestic mallard ducklings (Anas platyrhynchos) during the first three days of postnatal life. Twenty-four-hour-old ducklings were allowed to follow a stuffed mallard hen for 30 min. This experience resulted in a visually imprinted preference for the familiar stuffed hen over 4 stuffed ducklings in simultaneous choice tests at 48 and 72 hr after hatching, but only if the imprinted birds were kept in social isolation. Imprinted ducklings reared in a social group containing either same-age siblings or the stuffed mallard hen and same-age siblings displayed a visual preference for the stuffed ducklings over the familiar mallard hen at 48 and 72 hr tests. As a first step in the analysis of the features of the social exposure to siblings that are necessary for the redirection of the visually imprinted maternal preference, it was found that direct social interaction is essential to establish the preference for ducklings, but even mere visual exposure to siblings does away with the imprinted maternal preference. These results provide striking evidence of the ready redirection of a species-specific maternal preference in otherwise imprinted ducklings.