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The purpose of the project was to determine what effect human recreational activities, such as bear viewing and fishing, have on brown bears. Although a few studies have been done in the past about the presence of humans around brown bears, the studies didn’t show specifically how the presence of humans affects bears’ nutritional ecology. Nutritional ecology involves the study of how bears feed. This study looked at questions like:
Scientifically speaking, grizzly bears and brown bears are the same species. Brown bears, the coastal form of the grizzly bear, generally grow to a greater size due to the availability of highly nutritious food sources such as salmon. The kodiak is a subspecies of the brown bear and is larger in size. It is found only on Kodiak Island and two other smaller islands, which are located east of where we were working.
The project was located on state land just north of the Katmai National Park, which is at the base of the Alaska Peninsula. We were on the west fork of the Douglas River, very close to the Kamishak Bay. I was with a group of four other people: Lenore, from the National Aviary in Pittsburgh; Gail, from the Memphis Zoo in Tennessee; Diana, a keeper from the Oregon Zoo in Portland; and Diana’s husband David. We pretended to be tourists viewing bears so that researchers, located at nearby viewing points, could collect observations about how the bears were feeding in our presence.
In addition to collecting data on the bears while our group was present, the researchers also observed the bears for an hour before our arrival at the study site and for an hour after we departed. Observations were also collected by the research team at other times of the day and night. From early June to early September of this year, twelve different groups of volunteers, including my group, spent an average of six days at the site assisting with the project. Observations were collected almost every day, in weather conditions varying from warm sunny dry days to cold rainy days with heavy winds.
The majority of the time spent by the group of volunteers and one of the research biologists was at two observation platforms approximately forty meters from the river. This provided a good site to view the bears and also to be seen by the bears. Most of the participants were zookeepers from around the nation, or wildlife biologists. Last summer the project leader and three other wildlife biologists observed bears at the same location, though without the groups of pretend tourists. This served as the control portion of the project, aimed at understanding how the bears would seek food when groups of humans were not present.
During late August through early September—the bears were feeding heavily on silver salmon, also called Coho salmon. Although they ate some other food items, including dogfish shark and low brush cranberry, the majority of their feeding time was spent fishing in streams and the river for the salmon, which provided them with a very high fat and protein source. The salmon were following their annual spawning patterns by swimming from the ocean inland to freshwater creeks where the females would deposit their eggs to be fertilized by the males. Bears that caught female salmon benefited greatly from the roe, or eggs, in the female fish.
It is extremely important for bears, especially for females who may have bred earlier in the summer, that they eat great quantities of food through the summer and early fall. The bears must build a large amount of fat so that they can survive their winter denning period, known as winter carnivore lethargy or hibernation. Females that bred during the breeding season usually give birth to two to three young during the denning period, and it is crucial that they feed heavily earlier in the year in order for cubs to be born. If the presence of groups of people does affect how much food brown bears are able to find and consume before fall, then the survival rate of brown bears in areas where bear viewing and sport fishing take place could be affected in a negative manner.
My name is Hannah Decker, and I am a grizzly bear (Ursus arctos) keeper at the North Carolina Zoo. Recently, I had the opportunity to travel to Alaska and participate in a research project involving brown bears. This research trip was partially funded by a grant from the Randolph Friends of the Zoo and the North Carolina Zoological Society, while the research project itself is a joint effort between the Alaska Department of Fish and Game (ADF&G) and Washington State University, with funding from ADF&G.
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