Kodiak Brown Bears Love Their Elderberries

u.s. fish and wildlife service logoIn 2014, researchers uncovered something odd at Kodiak National Wildlife Refuge in Alaska. While studying the relationship between Kodiak brown bears and salmon, they saw the bears largely abandon salmon streams in July and August to chow down on elderberries.

Kodiak bear
It’s no surprise that many of Kodiak’s bears rely on salmon for a large part of their diet – but questions remain about how bears move across a landscape to “surf” the variable timing of returning salmon, what factors influence their choice of fishing areas, and when bears may utilize other food resources like berries. Photo by Lisa Hupp/USFWS

This year, the Kodiak Bear Crew (refuge bear biologist William Leacock, University of Montana doctoral student Will Deacy, biological science technician Caroline Cheung, and volunteers Shelby Flemming, Kristina Hsu and Andy Orlando) spent May through October in the remote southwest corner of the refuge to learn more about the ecological relationship between the spawning runs of the sockeye salmon and the Kodiak brown bear. 

PHOTOS: Explore Kodiak Refuge and its Bears

setting up a camera
The Kodiak Bear Crew sets up a remote salmon monitoring camera at O’Malley Creek. The white line is a chain of white panels strung across the streambed to improve visibility and the ability of the crew to estinate the number and timing of salmon migrating up this particular tributary. Photo by Andy Orlando

Using all sorts of clever technology, the team took more than 5.8 million photos with remote time-lapse cameras (solar-powered!) on 10 salmon streams, some to count the number of fish and some to determine how the bears used the streams. 

 

Kodiak Refuge is a wild place with no established trails. Traveling across county includes bushwacking through thick brush and crossing icy cold rivers and streams. Crew leader Will Deacy and volunteer Kristina Hsu navigate a particularly cold creek. Photo by Lisa Hupp/USFWS
Of course, that meant they had to analyze all 5.8 million photos, too, not to mention video, GPS data from collars on some bears and more. Beyond that, they stayed busy with equipment maintenance, aerial and ground surveys, lots of hiking… “Swamped waders, bugs swarming your eyes and mouth or a branch to the face” were just a few challenges volunteer Shelby Flemming mentions in her report on her summer. But what about those elderberries?

Elderberries
A large shrub growing throughout the Kodiak Archipelago, ripe clusters of bright red elderberries provide an important food source for Kodiak bears. Photo by Caroline Cheung/USFWS

 

Sure enough, they bloomed early again this year, and once again the bears left salmon-filled streams to gobble up berries. Volunteer Andy Orlando explains why: “It turns out that bears can most efficiently put on fat with a diet composition of 20-23 percent protein. Salmon, which make up a majority of the Kodiak brown bear’s annual caloric intake, is around 60 percent protein. … Elderberry, on the other hand, is a brown bear superfood, with a dry-matter protein content right at the sweet spot of approximately 23 percent.”

So one mystery solved.  Other questions no doubt remain about the Kodiak brown bear and how it can best survive in the modern world. Also of no doubt, the Kodiak Bear Crew will do its best to help the species thrive.

By Matt Trott, External Affairs, U.S. Fish and Wildlife Service, Department of the Interior 

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