FOLLOW THE WAGGLE DANCE FOR A SHORTCUT

Abstract

Nobel laureate Karl von Frisch was one of the first to describe the remarkable waggle dance that honeybees perform to direct other colony members to a tasty food source. Since his pioneering work, numerous researchers have taken up the challenge to decipher the components of this intriguing `dance communication'. Now, Rodrigo De Marco and Randolf Menzel at the Free University of Berlin reveal how a bee incorporates information about the whereabouts of a sugary treat into her waggle dance(p. 3885).We know that the honeybee's waggle dance conveys information about the distance and direction of a food source. But we don't yet fully understand how a forager represents her own `navigational' experience during a foraging flight in her subsequent waggle dance. Recently, Mandyam Srinivasan and colleagues discovered that bees flying through a tunnel decorated with contrasting patterns drastically overestimate the distance they have flown because bees use the images they see moving past them to determine how far they have flown. De Marco realised that this discovery would allow him to manipulate a bee's perception of the location of a particular foraging spot. By watching the forager's ensuing waggle dance, he would gain an insight into the bee's perception of both the distance and direction of the food source.First, De Marco used patterned tunnels to add a `virtual distance' to a bee's foraging flight and examine how she encodes distance in her dance. He wanted to find out whether bees measure the distance to a food source on their outbound flight (from the hive to the food) or on their inbound flight (from the food to the hive). De Marco placed a patterned tunnel 135 m from a hive,in line with a sugary food source, and trained some bees to fly through it on their outbound flight only, and others to fly through the tunnel on their inbound flight only. Upon their return to the hive, De Marco recorded the bees' waggle dances on video. Honeybees indicate distance by the duration of the `waggle phase', a single stride during which the bee waggles its abdomen. De Marco found that bees only performed longer `waggle phases' when they flew through the tunnel on their outbound flight; the bees were indicating that they had travelled 140 m inside the tunnel, when in fact the tunnel was 6 m long. But bees flying through the tunnel on their inbound flight did not overestimate the distance they had travelled. So bees mainly use the information gathered during their outbound flight to convey distance information during their dance.De Marco then tricked the bees by creating a mismatch between what the bees perceived to be the location of the food, and the actual food location. He placed the tunnel perpendicular to the straight line between the hive and the food source and trained bees to fly through the tunnel for the outbound flight only. Once they had visited the sugar treat, the bees made a beeline for their hive. Rushing back to the hive to examine the direction of the bees' dances,De Marco was delighted to find that the bees' dances indicated the inbound flight direction. The bees weren't fooled by the long detour through the tunnel; they were giving the direction of the shortcut they had just flown from the food to the hive. De Marco suspects that, at the start of the homeward flight, the bee takes in landmarks and uses this information when she subsequently dances in the hive.De Marco and Menzel conclude that a honeybee mainly relies on her outbound flight to encode the distance to an irresistible treat in her dance, but uses information gathered during her inbound flight to indicate the direction of the sugary reward.