MTPR

How Mapping Huckleberries Could Help Glacier Park's Grizzlies

Apr 2, 2019


A new study mapping huckleberries in Glacier National Park could help grizzlies thrive in the area, and figure out how the tasty fruits respond to a changing climate.

The study takes satellite images from NASA and high-resolution pictures from the United States Department of Agriculture to look down on the park from above and figure out exactly where the berries blossom.

"What we’re trying to do is really set the foundation for understanding the distribution of the species and how it changes across time," says Tabitha Graves, a research ecologist with U.S. Geological Survey and senior author on the study, which was published in the International Journal of Remote Sensing.

In the fall, huckleberries turn a brilliant, vermillion red. So when you’re looking down from above, it’s relatively easy to see how they snake across the park.

In peak season, the sweet berries make up about 50 percent of grizzly bear diet in the area.

"They basically will choose the maximum energy gain when they can," Graves says. "And so a food resource like huckleberries that can be in these very dense patches in some cases, is a really efficient way for them to put on the pounds."

Nick Mott: It’s like a power smoothie or something.

"Exactly, a berry smoothie," Graves says. "Yeah, they eat a lot of it."

Grizzlies are federally listed as threatened, and Glacier is part of the largest habitat for the bears in the lower 48. So this study is crucial to figuring out how to help the animals thrive, and to avoid conflicts with people. And Graves says the berries are also important for other animals like bees and birds and, of course, people too.

To make sure the aerial imagery matched what was on the ground, she says researchers conducted extensive surveys of vegetation in the field, which could mean the occasional berry eating along with the data collecting.

"This is edible research, for sure," Graves says. "It is fun to be out there doing this kind of research when you get a chance to be out there during the time period when it’s ripe."

She says the study starts to address the effects climate change and associated impacts – like increasing intensity of wildfire and drought, and changes in weather patterns – might have on the species.

But in addition to mapping over time, researchers also need to figure out the productivity of the plants, she says. So this is step one.

"So you think about it as the where, when and how much. And this is the where," she says.

While the maps might help park officials figure out how to manage bears and people, they won’t be of all that much help to intrepid berry-pickers, looking for new huckleberry hotspots.

"Part of why we felt comfortable working in Glacier National Park is because they have limits on the amount of huckleberries that people can pick," she says. "It’s one quart per person, so it shouldn’t be too much of a problem."

Plus, the vast majority of the huckleberries were more than 300 feet from trails, which is good for bears, too.

While field surveys have been going on for years, Graves says the satellite model itself took only a few months to construct. The details of complementary studies of berry productivity and change over time are still in the works.

She says future studies can use this model to map all kinds of other shrubs that change colors with the seasons.