The Interagency Grizzly Bear Study Team is continuing its research of grizzly bears in Yellowstone by taking DNA samples and fitting them with radio collars.
The agency is performing the research to monitor grizzly bear populations, mortality rates of the bears and food sources, including whitebark pine.
When looking at mortality rates, the IGBST looks to see if the mortality rates are “exceeding the threshold for those specific bear populations,” according to Frank van Manen, the team leader for the IGBST.
“We’ll sometimes delve into specific research projects and focus on the needs of our partner agencies. Right now we’re looking into the relationship between the production of whitebark pine as a food source for grizzly bears and how that relates to how the population is changing over time,” van Manen said.
The IGBST also is trying to look at other issues that are affecting food sources for grizzly bears, but are primarily focusing on whitebark pine because it was an issue that was discussed when a proposal to take grizzly bears off the endangered species list was denied.
“We’re putting quite a bit of effort into determining those relationships so that the fish and wildlife services and our partner agencies can make decisions on what the next steps should be in terms of any new de-listing proposal,” van Manen said.
The IGBST is also using radio collars as a form of research that allows them to gather more specific information about the bears including how they move around in the ecosystem, how they respond to change in food resources and how their survival changes over time, according to van Manen.
If the agency finds that a bear is no longer wearing its collar, researchers are able to track it down and find out why the bear is no longer wearing it and if it is due to a natural death or if there is reason to investigate the bear’s activities further.
DNA samples also are part of the research. When IGBST catches the bears to place radio collars on them, it also collects hair and blood samples to help determine which bears are related to each other as well as diet. When looking at the diet of the bear, researchers look to see how much meat the bear has eaten in contrast to plants, and also look at the health of the individual bears by analyzing their body fat.
The bears are released after the samples are taken.
The IGBST was formed in 1973 after a string of grizzly bear deaths in Yellowstone National Park due to the closing the garbage dumps in the park. This caused the bears to lose a big portion of their food source, according to the United States Geological Services.
Some of the research that IGBST does is related to Endangered Species Act because grizzlies are considered a threatened species and van Manen says the purpose of the IGBST is to help wildlife agencies make informed decisions when creating policies.
“The purpose of our unit is to provide unbiased and objective research. We don’t get into advocacy, we just want to provide the best science we can.”
