The Kew Royal Botanic Gardens have a problem: Their bumble bee population is in decline, and no one’s quite sure why. To hopefully shed some light on the phenomenon, scientists have developed a novel technology – tiny little bee backpacks that allow them to track the bees’ movements.
The backpacks, made from off-the-shelf parts, are small and light enough that they can be super glued to the bees without interfering with their lives or health.
The devices don’t track the bees via GPS – that would likely require too heavy a backpack. Instead, the transmitters are activated whenever the bees come within about eight feet of a receiver. That’s a big improvement over previous designs, which only worked at a distance of less than an inch. The data is transmitted via RFID chip, found in everything from credit cards to consumer products packaging.
The more readers they install, the better they’ll be able to understand the bees’ movements. As of now, they can surmise that the bumble bees have an average foraging time of about 20 minutes per day, suggesting that they travel about a .6 miles total.
“These tags are a big step forward in radio technology and no one has a decent medium to long range tag yet that is suitable for flying on small insects,” said Dr Sarah Barlow, a restoration ecologist from Kew Gardens.
In order to attach the backpacks, the bees are first cooled down in order to sedate them, though they still aren’t thrilled with the procedure. The device’s creator, Dr Mark O’Neill, says he solders every transmitter at his desk, and has made about 50 of them so far. He’d like to get the devices even smaller, he says.
As for why the bees are disappearing, no one’s quite sure. Predation doesn’t appear to be a factor – bees, even bumble bees, are pretty adept at detecting and evading predators. Instead, most of the bees are dying of old age, which in their world equates to about three months. Dr O’Neill’s backpacks should last for a bees entire lifetime.
It’s not just the Kew Gardens’ bees that are at risk. Across Europe, 10% of the 2,000 or so bee species face the threat of extinction, with another 50 expected to be in the same predicament soon. All around the world, in fact, bees appear to be in decline, which has scientists scratching their heads. For now, rural development and the corresponding destruction of wild meadow habitats are the most likely culprits. That wouldn’t explain a population decline in a protected area like a botanic garden, though.
“This piece of the puzzle, of bee behaviour, is absolutely vital if we are to understand better why our bees are struggling and how we can reverse their decline,” said Dr Barlow.