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DATE: October 5, 2009 3:45:06 PM PDT
WWU Grad Student Studying Dynamics of Grizzly/Salmon Relationship in Alaska

ABOVE: WWU grad student Ian Gill observes McNeil River's brown bears in their native environment as part of his study on bear/salmon dynamics.

 

Contact: Ian Gill, gilli@students.wwu.edu; or James Helfield, assistant professor of Environmental Science, (360) 650-7285, james.helfield@wwu.edu.

BELLINGHAM – Western Washington University graduate student Ian Gill spent his summer researching the predator-prey dynamic between grizzy bears and the chum salmon up close and personal in the McNeil River State Game Sanctuary on Alaska’s Cook Inlet, in an effort to understand the factors affecting the success of individual bears, how they learn, and how this interaction affects the health of both populations.

Gill, a native of Wrangell, Alaska, had an unusually experienced field assistant in Larry Aumiller, who was the manager of the game sanctuary for 30 years before retiring in 2005.  Together, Gill and Aumiller spent 374 hours – about 12 hours a day, every day, for almost five weeks – observing grizzlies feeding at McNeil River Falls. The observation platform, a simple gravel pad on the riverbank, allows unobstructed views of the falls and extremely close observation distances, as the bears would often come within a few feet of the observers.

“This is one of the most pristine wildlife viewing areas in the world,” said Gill. “To even get to the platform, you have to win a permit lottery, and visitors get four days of observation, all while in attendance with an Alaska Fish & Game employee. Because these bears have never been fed, never been shot at or molested in any way, they view observers as neutral entities. Since the program started in 1975, there hasn’t been a single bear attack.”

Gill had plenty of opportunity to test this theory over the summer, with as many as 48 grizzlies at once fishing in the falls next to his gravel pad.

“This is the largest naturally occurring seasonal congregation of brown bears in the world – so it’s an incredible chance to do this kind of research,” he said.

What brings the bears to McNeil River Falls every summer is the regular return of chum salmon to their spawning grounds above the falls.  The salmon provide an essential food source for bears before their winter hibernation; in turn the bears exert an important influence on survival rates and spawning success in the fish.  As the chum swim upstream through the falls, the bears perch, swim and lie in their path, using a variety of “fishing” techniques to catch their prey. Some squat in the falls and wait for salmon to literally bump into them; others perch on ledges near channels and swat the salmon as they go by; others swim in the water at the base of the falls like skin divers, grabbing prey under water as the salmon wait their turns to proceed upstream.

“Physical factors like river flow play an important role in determining how many fish are caught.  We’re also interested in understanding what makes some bears catch more fish than others. How does social dominance play a part in the selection of fishing locations or techniques, and lastly, how do these factors affect the two populations?” said Gill.

Gill and his advisor, WWU Assistant Professor of Environmental Science Jim Helfield, are collating Gill’s data in an effort to start finding some answers to those questions, and both say they hope to seek out grant funding to allow a second summer’s worth of observational data at McNeil River.

For more information on Gill’s project, contact him at gilli@students.wwu.edu.

WWU’s Huxley College of the Environment is one of the oldest environmental colleges in the nation and a recognized national leader in producing the next generation of environmental stewards. The College's academic programs reflect a broad view of the physical, biological, social and cultural world. This innovative and interdisciplinary approach makes Huxley unique. The College has earned international recognition for the quality of its programs.

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