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KODIAK: Brown Bear Response Changes in Food Resources
Alaska Region, April 14, 2010
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Bear locations prior to Karluk River salmon run collapse
Credit: WB Leacock/USFWS
Bear locations prior to Karluk River salmon run collapse Credit: WB Leacock/USFWS - Photo Credit: n/a
Movement of collared Karluk Lake bears 
in response to sockeye collapse
Credit: WB Leacock/USFWS
Movement of collared Karluk Lake bears in response to sockeye collapse Credit: WB Leacock/USFWS - Photo Credit: n/a
Capture and collaring Kodiak Brown Bear - WB Leacock & Joe Fieldman
Credit: VanDaele/ADFG
Capture and collaring Kodiak Brown Bear - WB Leacock & Joe Fieldman Credit: VanDaele/ADFG - Photo Credit: n/a
Capture, Monitoring, &  Collaring of Kodiak Brown Bear near Karluk Lake
Credit: VanDaele/ADFG
Capture, Monitoring, & Collaring of Kodiak Brown Bear near Karluk Lake Credit: VanDaele/ADFG - Photo Credit: n/a

Kodiak Refuge Biologist William Leacock is a man with a lot of questions. When habitats and resources shift or are disrupted, whether due to climate change or other factors, how will the Kodiak brown bear (Ursus arctos middendorffi) respond? Will they find alternate resources?  Will reproduction continue at current high levels?  To address these and other important questions, Bill and his coworkers at Kodiak National Wildlife Refuge initiated a major study in cooperation with the Alaska Department of Fish and Game and the University of Idaho. 

In a feasibility effort, Bill and Fish and Game Biologist Larry Van Daele captured and fitted three female bears with state-of-the-art GPS collars near Karluk Lake in late May 2009. Over 9,000 high quality telemetry locations were collected at hourly intervals from late May through November. Seasonal activity patterns, habitat use, and movement patterns were determined from these telemetry data.  Additionally, volunteers, Lee Arnold and Heidi Helling, and biological technician, Mat Sorum, hiked to over 570 remote bear locations collecting detailed site-specific information on plant communities, habitat characteristics, food resources, and evidence of bear activity. 

The results were fascinating.  Collared bears exhibited remarkable site fidelity from May through July making frequent short forays from higher elevations to nearby salmon streams – apparently checking on the status of the sockeye salmon run.  In early August, in evident reaction to the poor early 2009 Karluk sockeye salmon run (only 15% of the long-term average), collared bears left their core areas and traveled long distances in search of food. 

In Bill’s words, “The Moraine, O’Malley, and Falls Creeks sows went on a walkabout.” Between July 28 and September 2 the Moraine Creek sow traveled over 236 miles in her search for salmon, elderberry, and salmonberry before returning to the upper Karluk River where she fed on sockeye salmon until the end of September. The O’Malley Creek sow left Karluk Lake on August 5 for the head of Deadman Bay – traveling over 28 miles in 48 hours.  There she stayed for a month feeding on pink salmon. On September 3rd she headed back to Karluk Lake, making the 28 mile trip in 24 hours, and where she remained through November. 

“So far our studies seem to indicate that Kodiak bears are content to stick close to home as long as the food holds out, but in lean times, they are certainly capable of covering great distances in search of greener but probably already occupied pastures,” commented Leacock.

 “We’re looking forward to employing our approach in a larger study set to begin in May 2010, and perhaps we’ll be able to have better answers to the longer term questions.

 


Contact Info: William B. Leacock, (907) 487-2600 ext. 249, william_leacock@fws.gov
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