Elephants' Fear Of Angry Bees Could Help To Protect Them

Science Daily — At a time when encroaching human development in former wildlife areas has compressed African elephants into ever smaller home ranges and increased levels of human-elephant conflict, a study in Current Biology, suggests that strategically placed beehives might offer a low-tech elephant deterrent and conservation measure.

The researchers found that a significant majority of African elephants fled immediately after hearing the sound of bees, providing "strong support" for the idea that bees, and perhaps even their buzz alone, might keep elephants at bay. By contrast, the elephants ignored a control recording of natural white-noise, the authors reported.
"We weren't surprised that they responded to the threatening sound of disturbed bees, as elephants are intelligent animals that are intimately aware of their surroundings, but we were surprised at how quickly they responded to the sounds by running away," said Lucy King of the University of Oxford. "Almost half of our study herds started to move away within 10 seconds of the bee playback." King is also affiliated with Save the Elephants, a Kenya-based organization that aims to secure a future for elephants.
Earlier studies had suggested that elephants prefer to steer clear of bees. For instance, one report showed that elephant damage to acacia trees hosting occupied or empty beehives was significantly less than in trees without hives, the researchers said. In Zimbabwe, scientists have also seen elephants forging new trails in an effort to avoid beehives.
In the new study, the researchers tested the response of several well-known elephant families in Kenya to the digitally recorded buzz of disturbed African bees. Sixteen of the 17 families tested left their resting places under trees within 80 s of hearing the bee sound, the researchers reported, and half responded within just 10 seconds. Among elephants hearing the control sound, none had moved after 10 s, and only four families had moved after 80 s. By the end of the 4 min sound playback of bee buzz, only one elephant family had failed to move, whereas eight families hearing the control sound had not moved.
This behavioral discovery suggests that bees might very well be a valuable addition to the toolbox of elephant deterrents used by farmers and conservation managers across Kenya, King said. She added that such innovative approaches are sorely needed "to avoid extreme solutions such as shooting problem animals."
She cautioned that the use of beehives to shoo elephants away might prove to have limited application and that more research is needed if we are to understand its effectiveness. "But if we could use bees to reduce elephant crop raiding and tree destruction while at the same time enhancing local income through the sale of honey, this could be a significant and valuable step towards sustainable human-elephant coexistence."
The researchers include Lucy E. King of the Department of Zoology, University of Oxford in Oxford and Save the Elephants in Nairobi; Iain Douglas-Hamilton of Save the Elephants in Nairobi; and Fritz Vollrath of the Department of Zoology, University of Oxford in Oxford and Save the Elephants in Nairobi.
This work was supported by ESRC/NERC, The Wingate Foundation and Save the Elephants.
King et al.: "African elephants run from the sound of disturbed bees." Publishing in Current Biology 17, R832-R833, October 9, 2007.
Note: This story has been adapted from material provided by Cell Press.

Where Have All the Bees Gone?

More than one-fourth of the honeybees in the United States have disappeared since last fall, and scientists are trying to figure out why.

Entomologists—scientists who study insects—have a real mystery on their hands. All across the country, honeybees are leaving their hives and never returning.
It doesn't take long before a hive is nearly empty. Researchers call this phenomenon colony-collapse disorder. According to surveys of beekeepers across the country, 25 to 40 percent of the honeybees in the United States have vanished from their hives since last fall. So far, no one can explain why.

Colony collapse is a serious concern because bees play an important role in the production of about one-third of the foods we eat, including apples, watermelons, and almonds. As they feed, honeybees spread pollen from flower to flower. Without this process, called pollination, a plant can't produce seeds or fruits.

Now, a group of scientists and beekeepers has teamed up to try to figure out what's causing the alarming collapse of so many colonies. By sharing their expertise in honeybee behavior, health, and nutrition, team members hope to find out what's contributing to the decline and to prevent bee disappearances in the future.

Sick bees?

It could be that disease is causing the disappearance of the bees. To explore that possibility, Jay Evans, a research entomologist at the United States Department of Agriculture (USDA) Bee Research Laboratory, examines bees taken from colonies that are collapsing. "We know what a healthy bee should look like on the inside, and we can look for physical signs of disease," he says.

And bees from collapsing colonies don't look very healthy. "Their stomachs are worn down, compared to the stomachs of healthy bees," Evans says. It may be that a parasite is damaging the bees' digestive organs. The bees' inability to ward off such parasites suggests that their immune systems may not be working as they should.

The honeybees have other signs of troubled immune systems, such as high levels of bacteria and fungi inside their bodies, says Dewey Caron, an entomologist at the University of Delaware. He's one of the leaders of the colony-collapse research team.

But why would parasites, bacteria, or fungi in the body cause bees to leave their hives? After all, when you're sick, you want to stay at home, right?

Caron says that some of these disease-causing agents may lead to disturbances in bee behavior. "It may be that sick bees are not processing information correctly and learning where home is," he says. In other words, a sick bee might leave the hive and simply forget how to get back.

If enough of the bees in a colony can't find their way home, he says, it's just a matter of time before the colony collapses. Being social insects, even healthy bees are unable to live long on their own. And once the bees vanish, the crops that they usually pollinate are in trouble.

Environmental clues

Another cause of colony-collapse disorder may be certain chemicals that farmers apply to kill unwanted insects on crops, says Jerry Hayes, chief bee inspector for the Florida Department of Agriculture. Some studies, he says, suggest that a certain type of insecticide affects the honeybee's nervous system (which includes the brain) and memory. "It seems like honeybees are going out and getting confused about where to go and what to do," he says.

Adding to the mystery, Hayes says, is an observation about moths and other insects that frequently use empty beehives to raise their own young.

"Usually, they move right into an empty hive," he says, "but now they're waiting several weeks before they do." As Hayes sees it, this suggests that something repellent in the hive may not only be driving out bees but also keeping other insects from moving in, he says. So far, scientists haven't identified what that repellent thing could be.

Looking at bee genes

If it turns out that a disease is contributing to colony collapse, bees' genes could explain why some colonies have collapsed and others have not. In any group of bees—or other animals, including people—there are many different kinds of genes, because each individual has a slightly different unique set of genes. The more different genes a group has, the higher the group's genetic diversity. And genetic diversity is a plus as far as survival is concerned.

Some scientists are now studying genetic diversity in honeybee colonies to see if it has an effect on colony collapse disorder.

"If a colony is genetically diverse, it's less likely the colony will be wiped out completely from a sweeping infection or disease," says David Tarpy, a University of North Carolina entomologist. That's because at least some bees in a genetically diverse group are likely to have genes that help them resist any specific disease that gets into the colony, he says. Scientists haven't determined the role of genetic diversity in colony collapse, but it's a promising theory, says Evans. He and his colleagues at the USDA bee lab are currently running genetic tests on bees from collapsing colonies. Their goal is to find out whether there are genetic differences between the bees that vanish and those that remain in their hives.

Scientists are working hard to figure out the causes of colony collapse. Meanwhile, bees continue to disappear. Can anything be done to help them survive?

Tarpy suggests that more people could raise bees to help restore their numbers. "Given this decline in honeybees, if you want to get active in helping to promote pollination, the best thing to do is to become a beekeeper and keep your own bees," he says.

Don't be put off by the possibility of a sting, says Dan Geer, who raises bees in North Smithfield, Rhode Island. First of all, beekeepers can wear protective gear. And bees, he says, have a bad rep. "You'd be surprised by how gentle they are," he says.