August 2, 2005

Researcher: Bird Emits Mosquito Repellent

FAIRBANKS, Alaska (AP) -- A bird species found in some parts of Western Alaska is believed to emit a natural mosquito repellent with properties similar to DEET, the key ingredient in many commercial repellents.

Hector Douglas, a University of Alaska Fairbanks researcher, said he made the discovery in the feathers of the crested auklet after applying a little scientific intuition and sacrificing some of his own blood.

"It's perhaps an example of how there are natural products in nature that have the potential to be utilized," Douglas said.

Clues to the crested auklet's unique ability to repel mosquitoes and pests like ticks and lice was apparent the first time Douglas encountered the creature, one of four auklet species in Alaska. He had been dropped at Kiska Island in the Aleutians to conduct research for the U.S. Fish and Wildlife Service.

The birds feed en masse on zooplankton in the ocean and return as a group, 1 million strong. As they began landing, the first clue was right under his nose.

"It was literally like stepping into a Dr. Seuss story," Douglas said. "The birds would come down and have this citrus smell and they're landing on the rocks all around you and they have these elaborate social interactions. It was pretty peculiar, the first time it happened."

He noticed the birds had little trouble with ticks compared to other species of auklets and seabirds.

The citrus smell reminded him of a research paper he'd read about birds that rubbed citrus peels in their feathers to help ward off pests, which at best are nuisances and at worst carry disease.

It wasn't until years later, however, when he was studying auklets on St. Lawrence Island in the Bering Sea where mosquitoes are more prevalent that he began to see the compound's effect on the airborne pests.

To test his theory, he went into the laboratory with a few auklet feathers. An analysis showed him the chemicals that make up the auklet's "odorant." Most are available commercially.

He then tested their repellent properties using mosquitoes specially bred at a research lab in Florida for their aggressive tendencies. Douglas dabbed test samples on filter paper, attached that paper to his hand, then put it in a cage with hungry mosquitoes.

It was clear the auklet samples kept mosquitoes away.

"They soon give up trying to land and rest on the side of the cage," Douglas said. "It's a similar reaction to DEET and other repellants. It overwhelms their sensory systems."

Douglas detailed his findings in a "Journal of Medical Entomology" paper. The research is part of his doctoral thesis. He said he was unsure if it will lead to something like a commercial repellant.

"It has potential, but at the same time you'd have to do further research to find out if it's safe to use on the skin," he said.

"I've really just taken the first step. ... I'm just trying to determine the use in nature."


Information from: Fairbanks Daily News-Miner, http://www.newsminer.com