The waggle dance is a rather enigmatic behaviour. Gyrating and walking in a figure-of-eight pattern, bees communicate the location of luscious flowers to their fellow foragers. Ryuichi Okada and colleagues from Japan explain that although waggle dances are renowned for recruiting foragers, no one had directly measured whether this translated into foraging success and affected the amount of food obtained for the colony. So, the team decided to test the impact of the bees’ intriguing behaviour on their foraging success ()
Explaining that waggle dancing bees release air-borne chemicals that encourage other residents of the hive to follow their guidance, the scientists realised that they had to prevent returning foragers from communicating in any way with their hive mates, and they did this by touching the insects with a brush. The team then alternated days when the insects were allowed to waggle with days when they were prevented from dancing and weighed each hive at the end of each day to find out whether communication had affected the amount of food that the foragers retrieved. The team also repeated the experiments over a period of years – always in the early autumn – and at three different locations in
Japan to be sure that no other factors influenced the bees’ foraging success.
Comparing the hives’ masses, the team found that they all lost mass consistently over the course of the experiment. ‘This was an expected seasonal change for the species’, the team says, explaining that the hive loses mass over the winter as the bees forage less. However, when the team scrutinised their results closer, they realised that the hives where the bees were not allowed to waggle dance lost more mass than the hives where the bees danced. They also realised that the bees were able to adapt to their altered circumstances, as the hives that were allowed to waggle dance on the first day of the experiment lost less mass than hives that were only permitted to waggle dance on the second day. ‘Because the colonies of both groups were allowed to communicate – waggle dance – [one group on the first day and the other group on the second day] we expected close values of weight change. However, very different values came out’, says Okada.
So, Okada and his colleagues have shown that waggle dancing does impact on the amount of food collected by the hive and that foragers can adapt to altered circumstances. The team also discovered that the number of waggle dances affected the hive’s mass gain and they say, ‘the dance is effective to maintain the colony.’
