Yale Bulletin and Calendar

October 4-11, 1999

Volume 28, Number 7

Researchers discover animals will
shun others with infectious diseases

A new study by Yale scientists has found that animals can recognize and stay away from other animals that may infect them with a disease.

Research by Yale professor David Skelly and his collaborator, Joseph Kiesecker, who is now at Penn State University, shows that healthy animals can distinguish the odors given off by infected animals and will keep their distance from diseased individuals.

"Biologists had long speculated that animals might gain an advantage from being able to avoid diseased animals, but there was no experimental evidence," says Skelly, a professor of ecology and evolutionary biology at the School of Forestry & Environmental Studies. "If these behaviors are widespread, they could be important in making accurate predictions of the spread of disease."

In the study, which was published in Proceedings of the National Academy of Sciences, the researchers found that bullfrog tadpoles were able to tell when others of their species were infected with a fungus that attacks the digestive tract. Healthy tadpoles can become sick by spending time near infected animals.

When presented with an infected bullfrog tadpole, the tadpoles moved up to a foot away," says Skelly, noting, "Healthy tadpoles appear to be able to smell chemicals in the water associated with the tadpole's illness and stay away from them."

The nature of the chemical cue is entirely unknown. "Identifying the cue is a logical next step," he adds.

Skelly and Kiesecker have found that tadpoles are highly sensitive to their environment.

"Our understanding of predators and their prey has changed drastically since it was discovered that many kinds of prey animals can change their behavior and even their body shape when they smell nearby predators," Skelly says. "Responding to disease risk may be quite similar from an animal's perspective. In both cases animals appear to be able to use behavior to reduce the chance that they will be harmed or die."

-- By Jacqueline Weaver

T H I SW E E K ' SS T O R I E S

Women with breast cancer genes risk relapse with conservative therapies

Ex-Secretary of State describes greatest foreign policy challenges facing the U.S.

Researchers discover animals will shun others

Exhibit will offer Yale community a peek at libraries' treasures

HHS Secretary to talk about Medicare, privacy issues

NY governor, UPenn president are year's first Chubb Fellows

Solicitor General Waxman to speak at Law Reunion

Conference to explore 'dilemma' over use of cost-benefit analysis to make policy decisions

Headstone dedication will highlight Divinity Convocation

Goethe's contributions to science, modern culture celebrated

Grant supports STAR program to promote success in sciences

Scientists studying how animals move in perfect tandem

Two-part sculpture coming together for first time at Yale center

Human figure and landscape explored in Asian art exhibit

Exhibit features works of Chinese artist who mixes Western and Eastern styles and symbols

Yale hosts day-long conference on Asian studies

Stalin's secret plans to invade Alaska among topics discussed at international conference . . .

Yale launching annual United Way fundraising drive

Series focuses on slavery in early U.S. and the Middle Ages

Drug for glaucoma will be tested in clinical trial at the medical school

Medical program will focus on topic of breast cancer

German scholar to speak to local Humboldt chapter members

. . . In the News . . .

Campus Notes