Social learning strategies in honeybee foragers: do the costs of using private information affect the use of social information?

Abstract

Individual honeybee foragers often need to decide between using private versus social information when choosing where to forage. Social information is provided by the waggle dances made by successful foragers. Experienced foragers also have private information about the feeding sites they have previously visited. Previous work has shown that honeybees are flexible in their information use strategy. However, the conditions that favour the use of one information source over the other remain poorly understood. It has been suggested that foragers rely more on social information when use of private information becomes more costly. We tested this by training two groups of foragers to two feeding sites, 120 or 600 m from the hive, both providing a sucrose solution identical in concentration. We then made these two locations unrewarding and observed whether foragers trained to the further, and therefore more costly to check, site paid more attention to dances for a third, closer site (120 m in a different direction) than foragers trained to the 120 m site. Contrary to prediction, foragers trained to the 600 m feeder followed dances for the novel feeder less (25% fewer waggle runs) than foragers trained to 120 m feeder. Foragers from the distant feeding site were also not more likely to arrive at the food source advertised by dances. Our results suggest that higher costs of private information do not increase the use of social information as long as bees are satisfied with their original food source (i.e. they use a ‘copy-if-dissatisfied’ strategy). Additionally, we show that switching from private to social information is preceded by a rapid motivational change. Minutes before switching to the advertised resource, the foragers increased their dance-following time by 65% compared with earlier dances.