AMAZING BEE STORIES:
How do bees find flowers?
By Andy Welch
Bees fly at about 15mph, so how can they find flowers when flying so quickly?
It turns out that bee vision works about 5 times faster than human vision and is one of the fastest in the animal kingdom. So if a bee went to the cinema they would see the movie as a series of static images as their vision is so much faster than ours.
But excellent vision at speed isn’t enough, as bees only have tiny brains and the process of just staying in the air and not flying into walls is pretty complex. So in order to simplify things, bees switch off colour vision at speed and fly in black and white. They only revert to colour when they slow down closer to flowers.
As the bee approaches the flower, it is guided by smell but also by ultra-violet patterns on the petals. Ultraviolet is invisible to humans, but the visual spectrum of bees has evolved so that instead of seeing a red-to-violet spectrum like humans, the bee vision spectrum is slightly shifted, and they see orange-to-ultraviolet. So bees can see UV at one end of the spectrum, enabling them to see the UV patterns on flowers, but they can’t see the colour red at the other end. They can still see red flowers like poppies, but they appear black to a bee.
When the bee lands, it searches for nectar, and the flower needs to calculate precisely how much nectar to provide. It needs to provide enough to attract a bee, but not so much that it can fill up in a single visit, as pollination will only occur if the bee visits several flowers.
So each flower produces a small amount of nectar, and when there is none left, the bee leaves a scent on the flower to say ‘empty’. The scent wears off when the flower has created more nectar.
Flowers don’t want to waste energy creating too much nectar, and bees don’t want to waste energy visiting empty flowers, so somehow, they came up with this clever compromise.
Flowers also realised that being brightly coloured and smelling nice wasn’t enough, and they also needed to evolve into different shapes to survive. The shape is important as it means the nectar is in a slightly different location for different flower species. Bees are pretty lazy, so once they have learned to find the nectar in one species of flower, they will typically spend all day visiting the same species as they can't be bothered to learn another flower shape. And this is precisely what the flower wants it to do to maximise pollination within the same species. So it looks like the bees have evolved to take advantage of flowers, and the flowers have evolved to take advantage of the bees, which is pretty clever.
ABOUT THE AUTHOR
Andy Welch is a data and analytics specialist, who provides technology and data science support to The World Bee Project. This includes helping to manage the World Hive Network data sets as well as providing analytics support for The World Bee Project's global research projects