Climate change is having an unexpected effect on the diets of grizzly bears and making them switch from salmon to berries, and scientists say that could cause problems in the future.
Grizzly bears are omnivores that eat meat and plants. According to The Telegraph, the bears on Kodiak Island in Alaska normally eat salmon at the beginning of the summer. Scientists estimate that the bears usually eat about 75 percent of the sockeye salmon population in the area’s streams. Then, when the area’s elderberries ripen at the end of the summer, the bears go eat berries instead. At least, that’s what usually happens.
Now, however, a new study indicates that increasing temperatures mean the elderberries are ripening earlier. Now the bears have a choice between berries and salmon, and it looks like they’re choosing salmon. Researchers say the bears left the streams full of salmon, and they stayed in the hills eating elderberries instead.
"It's essentially like if breakfast and lunch were served at same time and then there is nothing to eat until dinner,” said Oregon State University biologist William Deacy. "You have to choose between breakfast and lunch because you can only eat so much at a time."
Berries are higher in sugar than salmon. They contain less protein and are easier for the body to break down, and scientists say the bears are gaining weight as a result.
The change in the bears’ diet is also affecting the Kodiak Island ecosystem. Normally the bears kill 75 percent of the salmon at the beginning of the summer. Now there are a lot more surviving salmon. And it turns out the decomposing salmon carcasses left behind by the bears play an important role in fertilizing the ground. The forests in the area are reportedly suffering from the lack of nutrients normally provided by the salmon carcasses.