Smells trigger memory for hungry bees
Lucy Andrew for News in Science
Australia - 29/01/2004
Smells remind bees of where they once had a great meal, according to Australian research.
Dr Judith Reinhard and team at the Australian National University in Canberra found that when honey bees were reminded of a smell, they could find their way back to the food using visual clues to guide them.
The results appear in today's issue of the journal Nature.
According to Reinhard, this was the first time researchers had shown honey bees (Apis mellifera) in the field use smell to recall visual memories.
"It's just like what happens with humans and smell," said Reinhard.
When they smell freshly baked cake, they can immediately remember what the cake looks like, tastes like, even though they don't see the cake."
The study had two phases. In the first phase, the researchers placed feeders in particular locations 50 metres from the bee hives. The feeders contained sugar water scented with lemon, rose or almond. The honey bees learned which scent was where.
In the second phase, the researchers exposed the bees in the hive to a scent of lemon, rose or almond, and watched how they behaved. The researchers then placed empty feeders with no scent in the original positions.
Honey bees: memories are made of this
(Jeffrey Wilson, RSBS Photography, ANU)
More than 80% of bees flew to where they remembered the scent was. Most bees also circled and landed on the empty feeder, which Reinhard said indicated they were convinced food must be there.
Bees navigate by using landmarks along their path. They also use a special waggle dance to tell other bees how far away food is.
Researchers are divided about the relative importance of the waggle dance compared with other ways of finding food, such as scent and landmarks.
Most researchers think the waggle dance is important but scent is important too, said Reinhard.
Bees are a great model for studying learning and memory in humans, Reinhard said. And there are many parallels between the way humans and bees store and recall memories.
Studying bee learning and memory is also much easier than studying humans, said Reinhard.
And with the publication of a draft copy of the honey gene genome earlier this year, researchers can start looking for molecules and genes associated with bee memory. "It makes it much easier to then try and find [these genes] in humans," said Reinhard