San Diego – Shikari is making that huffing sound that polar bears make when they’re checking out their surroundings.
The 12-year-old, 550-pound Ursus maritimus is also eyeing the four humans watching her from behind steel bars. Her thick black nose is twitching with the scent of her visitors.
But most important, Shikari is listening – listening to tones being generated by a computer. Her small rounded ears perk up as each tone is sounded.
When she hears a tone, she has been trained to press her nose on a pad. Through the bars, researcher JoAnne Simerson gives her a tasty brownish morsel called “omnivore chow.”
It’s all for science.
Shikari and her twin sister, Chinook, are part of the first-ever study of polar-bear hearing. The project began in September at San Diego Zoo, in cooperation with Sea World.
With the oil and gas industries looking to explore and expand drilling activity in Alaska, researchers want to discover what the noise from such exploration would do to polar bears, particularly females who are pregnant or nursing cubs.
Funding for the study, up to $60,000, comes from BP, formerly known as British Petroleum. The Louisiana-based conservation group Polar Bears International acted as middleman for the grant.
After testing of Shikari and Chinook is finished, similar tests may be done on Sea World’s polar bears, Charly, Szenja and Snowflake. The zoo and Sea World worked together before on a study of polar bears’ reproduction cycles.
Shikari and Chinook were chosen for the current study because researchers are primarily interested in adult females. The zoo’s other polar bears, the female Tatqiq and male Kalluk, are only 6 years old and not yet sexually mature.
Although the hearing study is being underwritten by the oil industry, researchers say they are not taking sides in the hot issue of expanding oil drilling in Alaska. The findings will be printed in a scientific journal next year.
“It behooves both sides of the argument to know what the reality is,” said Megan Owen, a lead researcher with the zoo’s Conservation and Research for Endangered Species facility. “We’re just gathering the data.”
Polar bears are the world’s largest land-based carnivores, but the sum of knowledge about them is spotty, researchers said.
It’s known a polar bear can smell a seal 20 miles away and can swim at speeds up to 6 mph, but estimates of their hearing capacity are largely guesswork.
“We know almost nothing about the hearing of bears, great cats and (hoofed animals),” said Ann Bowles, bio-acoustic specialist at the Hubbs-Sea World Research Institute. “We’re in a state of blankness.”
There have been some tests in the wild to gauge what bears can hear. In one test, a researcher blew a high-pitched dog whistle near a group of brown bears.
“It created a stampede,” said Scott Schliebe, a polar bear specialist with the U.S. Fish and Wildlife Service.
Still, one test in the wild does not make for a scientifically valid conclusion.
Schliebe and other polar bear specialists are eagerly awaiting the results of the San Diego Zoo research.
