Ontogeny of orientation flight in the honeybee revealed by harmonic radar

Cognitive ethology focuses on the study of animals under natural conditions to reveal ecologically adapted modes of learning. But biologists can more easily study what an animal learns than how it learns. For example, honeybe es take repeated 'orientation' flights before becoming foragers at about th ree weeks of age(1). These flights are a prerequisite for successful homing .(2) Little is known(2,3) about these flights because orienting bees rapidl y fly out of the range of human observation. Using harmonic radar, we show for the first time a striking ontogeny to honeybee orientation flights. Wit h increased experience, bees hold trip duration constant but fly faster, so later trips cover a larger area than earlier trips. In addition, each flig ht is typically restricted to a narrow sector around the hive. Orientation flights provide honeybees with repeated opportunities to view the hive and landscape features from different viewpoints, suggesting that bees learn th e local landscape in a progressive fashion. We also show that these changes in orientation flight are related to the number of previous flights taken instead of chronological age, suggesting a learning process adapted to chan ges in weather conditions, flower availability and the needs of bee colonie s.