Climate change is causing the tongues of bumblebees to SHRINK

• Tongues of two Rocky Mountains species of bumblebees analysed 
• Were about one-quarter shorter than they were 40 years ago
• Climate change altered the buffet of wildflowers they normally feed from 

By Mark Prigg For Dailymail.com

Published: 17:57 EST, 24 September 2015 | Updated: 18:21 EST, 24 September 2015

Global warming and evolution are reshaping the bodies of bumblebees, a new study has found.

The tongues of two Rocky Mountains species of bumblebees are about one-quarter shorter than they were 40 years ago, evolving that way because climate change altered the buffet of wildflowers they normally feed from, according to a study published in the journal Science.

In one of these species, the tongue had been half the size of the bee's body - the equivalent of a human tongue going down to the waist. 

Scroll down for video 

The tongues of two Rocky Mountains species of bumblebees are about one-quarter shorter than they were 40 years ago, researchers found.

But because the flowers where the long tongue is required have dwindled, the bees didn't need that much tongue. 

Keeping long tongues requires bees use more energy, so the bees evolved a shorter tongue that allows them to sample a wider variety of flowers, said study lead author Nicole Miller-Struttmann at the State University of New York, Old Westbury.

While biologists have tracked how global warming has altered the developmental, migration, timing and other behavior in plants and animals, what makes this study unusual is the physical changes in the bees, said study co-author Candace Galen at the University of Missouri.

'It speaks to the magnitude of the change of the climate that it's affecting the evolution of the organisms,' Galen said. 

'It's a beautiful demonstration of adaptive evolution.'

Sydney Cameron at the University of Illinois wasn't part of the study, but praised it as well conducted and significant for the ecosystem of mountain flowers.

The team of biologists studied the bees on three isolated mountaintops in the Rockies, where they had been the most dominant species around. 

Not so much anymore, Miller-Struttmann said. 

The longer tongued of the two bees, the golden belted bumblebee, shrank from 50 percent of all the bees to 20 percent, she said.

Because these were so isolated and so high - more than 10,000 feet - pesticides and pathogens, often blamed for bee declines, weren't a problem, the scientists said. Something else had to be an issue. 

They compared the bees to those of 40 years ago or more and found the tongues dramatically shorter.

They also found that the temperature in the area had warmed by about 3.6 degrees since the 1960s and the type and amount of flowers had changed.

At first, the scientists figured the flowers were evolving with the bees, as often happens over long time periods in nature, but Miller-Struttmann said that's not the case.

'The silver lining is that (the bees) are evolving very quickly,' Miller-Struttmann said. 

'The story may not be as rosy for the flowers.'

Galen worries that without long-tongued bees, some flowers will falter. 

Also, she said shorter tongue bees often 'cheat' and bite a hole in the flower's side, which doesn't help the plant spread its seeds.

Recently experts have spotted the creatures swiftly extracting nectar and pollen from the nearby nests of other bees.

Bee burglars: Scientists at Sussex University have previously found that rather than searching far and wide for the right flower, one in eight bumblebees seemed to be pilfering their day's bounty from nearby nests (file picture)

Scientists at Sussex University found that rather than searching far and wide for the right flower, one in eight bees seemed to be pilfering their day's bounty.

This 'perfect strategy' allows the bees to spend minimal energy, while making the job of pollination even harder for their oblivious neighbours.

The team set up three colonies in East Sussex and tagged some of the bees with radio frequency chips, which tracked their movements.

Lead researcher Dr Ellen Rotheray told BBC's Farming Today: 'When I had a quick look at the data I realised that individuals from different colonies were entering their neighbouring colonies and within a minute they were exiting that colony and re-entering their own colony.

'It's a perfect strategy really because they don't have to go out and find the flowers and use energy to collect pollen and nectar – it's right next door.'

'Around 14 per cent of those that I marked. It doesn't mean there is less pollination going on, it does mean that neighbouring colonies has to work harder to gather their resources.'

She added: 'We absolutely didn't expect the results... We can't tell at the moment if they are necessarily stealing pollen or nectar, or whether it's a particularly successful strategy, but it saves them having to go out and find pollen of their own... I'd like to put cameras in there to see what is happening, it's interesting behaviour.'

With the UK's bumblebee population in a serious decline, researchers are keen to understand more about how they work.

Changes to the British countryside, including the loss of hundreds of wildflower fields, has seen two species of bee become extinct within the last 70 years.