Another Hot Topic

The BeeHolder, Spring 2013

We were always taught that workers went through a number of roles between emerging and death, nurse, cleaner, guard, forager. We do know that if the nurse bees are lost then the foragers can change their behaviour and feed the brood, but another factor has been revealed in the assignment of roles within the hive. A short piece from Richard Hammond's Invisible Worlds (BBC, March 2010) shows that different temperatures within the hive control which roles the workers take up. It is a shame that such excellent scientific reporting using state-of-the-art technology normally out of the reach of research academics is ruined by emotive reporting. The following is the script of the programme unedited except for the underlining of some cringe-worthy adjectives that I think degrade what is otherwise an excellent report. (am I being fair? Can you spot more irritations? To what extent does popularist reporting degrade the science?).

“... inside a bee hive is one of the most sophisticated living things in the history of evolution. One bee on its own doesn't amount to much, but taken together a very different picture emerges. Seen normally, all these bees may look the same, but go beyond the ordinarily visible into the infra-red and some bees are warmer than others. Some glow bright orange like hot coals, radiating heat to their surroundings. Others are dark and cool. It's the precise control of heat that allows a bee colony to be such a unique and successful form of organisation.

Bee doing a firefly impressionBut what is all this heat for? Heat is concentrated in one central area of the hive, the brood nest, where young bee pupae are growing. A bee that may appear relatively still, when looked at in infra-red is glowing bright orange, revealing its role as a specialist heater bee. The bee warms itself up by vibrating its flight muscles - vibrations that allow it to warm up to 44 degrees centigrade, previously thought to be high enough to kill it. Others that seem to be grabbing a quiet snooze are actually tight little balls of fire that are acting in a motherly role to keep the brood warm. Without warmth the babies will not grow and develop. It is also now clear why bees spend so long foraging for nectar that will be turned into honey, as over two thirds of the hive's honey goes on the central heating of the colony.

A rarely seen moment is caught on camera when an exhausted heater bee is topped up by a refuelling bee just returned from foraging.

These images have revealed something extraordinary. By precisely controlling the temperature, these heater bees control the destiny of the young. Incubated at 34 degrees, the newly born bees are likely to become humble housekeepers, but kept just one and a half degrees warmer, they may instead turn into intelligent and high-ranking foragers, living up to 10 times longer. None of these new discoveries would have been possible without our ability to see into the infra-red spectrum.”

Watch the small clip, maybee it promotes empathy for the bee more than any written text.

Tony Shaw (with gratitude to the BBC)