Bees like it hot

Aug 02, 2006
Bees like it hot
A ´hot bee´ on a flower, taken with a heat sensitive infrared camera. J. Tautz, M Kleinhenz & B. Bujok @ BEEgroup Würzburg

Research from Queen Mary, University of London has shown that bees prefer to visit warm flowers, and can learn to use colour to predict floral temperature before landing.

In the hunt for their next meal, it’s long been thought that bees head for the flowers that contain the most nectar or pollen. But as bees need to invest energy in maintaining their body temperature, a flower’s temperature might be seen as another reward.

Writing in the journal Nature, Queen Mary's Professor Lars Chittka and his collaborators from the University of Cambridge (Adrian G. Dyer, Heather M. Whitney, Sarah E.J. Arnold, and Beverley Glover) have shown that in a world where flowers of different species differ in temperature, bees might cleverly pick the ones that offer warmer nectar - and they can learn to identify such warm flower species by learning these species' flower colours.

Chittka and his team tested whether the bees could use flower colour to identify warmer flowers. In a ‘foraging bout’ the bees were offered a choice of four purple artificial flowers and four slightly cooler pink flowers, placed in random positions.

58 per cent of the bees chose the warmer, purple flowers. And when the colours were switched and the pink blooms held the warmer nectar, 61.6 per cent of the bees preferred the pink flowers.

Chittka explains: “What the bees appear to be doing is a bit like us drinking a hot drink on a cold day. If you need to warm up, you can produce your own heat, at the expense of some of your energy reserves - or you can consume a warm drink, and save on investing your own energy,” he said.

“The interesting thing is that bees don't just prefer the warmer drinks - they also learn to predict the flower temperature from the flower colour.” The results show that floral temperature can serve as an additional reward for pollinating insects in a context where there are also nutritional rewards available.

Flowers have a variety of tricks by which they warm themselves: some species are thermogenic, i.e. they can produce their own heat; others make use of the absorption of solar radiation, either passively or through a range of structural adaptations.

The findings may have importance for the evolution of specific floral structures and for the connection between floral sensory cues, floral temperature and pollinator behaviour.

Source: Queen Mary, University of London

Explore further: New conversion process turns biomass 'waste' into lucrative chemical products (w/ Video)

add to favorites email to friend print save as pdf

Related Stories

Flowers' polarization patterns help bees find food

Jun 05, 2014

Like many other insect pollinators, bees find their way around by using a polarization sensitive area in their eyes to 'see' skylight polarization patterns. However, while other insects are known to use such ...

Lord of the bees

Mar 21, 2014

(Phys.org) —James Hung has collected more than 17,000 wild bees from coastal, desert and mountain areas of San Diego County. But many of his specimens bear little resemblance to the honey bees we normally ...

Recommended for you

Protections blocked, but sage grouse work goes on

9 hours ago

(AP)—U.S. wildlife officials will decide next year whether a wide-ranging Western bird species needs protections even though Congress has blocked such protections from taking effect, Interior Secretary ...

Contrasting views of kin selection assessed

10 hours ago

In an article to be published in the January issue of BioScience, two philosophers tackle one of the most divisive arguments in modern biology: the value of the theory of "kin selection."

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.