Navigation in a cup: chick positioning in great tit, Parus major, nests

Parent birds often feed from predictable sites at the nest and nestlings compete for access to positions close to them. Such scrambling for stable parentally favoured positions may relate to optimal foraging theory. For efficient foraging, nestlings should be able to associate begging payoffs with the available positions in the nestcup and use this information to position themselves before parental arrival at the nest. We tested this prediction experimentally in the great tit by keeping nestlings temporarily in the laboratory where they were housed individually in nestboxes identical to their natural boxes. After a period of food deprivation, we quantified their positioning, taking the nest entrance as a reference. Parental feeding locations were measured from videos made at the natural nests, again relative to the nest entrance. As predicted, nestlings in the laboratory boxes chose positions significantly closer to parental feeding sites than expected by chance. Thus, they had knowledge about their parents' habit of feeding from predictable sites, enabling them to navigate and forage efficiently in the nestcup.