Bear saliva on dead fish offer biologists a gold mine of scientific data

CORVALLIS, Ore., Nov. 9 (UPI) -- Wildlife biologists in Oregon have discovered a unique source of scientific data: bear saliva left on fish carcasses floating down the rivers of the Pacific Northwest.

According to a new study published in the journal PLOS ONE, genetic analysis allows scientists to match bite marks in partially eaten salmon to individual bears. The new analysis strategy outperforms similar tracking techniques using fecal matter.

"When salmon are plentiful, bears rarely eat the entire fish," lead study author Rachel Wheat, an ecologist who recently completed her PhD at the University of California, Santa Cruz, said in a news release. "In some cases, they only eat the brain, and we've found that swabbing along the edges of the braincase gives us the best results for extracting DNA."

Researchers say the new analysis technique will make it easier to monitor the growth, health and distribution of brown bear populations in the Pacific Northwest.

"We found that using bear saliva is not only easier and cheaper as a research tool, it is more effective," added study co-author Taal Levi, an assistant professor of fisheries and wildlife at Oregon State University.

Researchers hope their findings will inspire other biologists to explore the benefits of saliva sampling.

"Many predators leave saliva on food remains," Levi said. "We feel this type of saliva sampling could become an important tool for wildlife population monitoring."