Grizzly Bears Switch From Salmon To Berries As Climate Changes

While humans grapple with "Meatless Mondays," grizzly bears are choosing a vegetarian diet in order to adapt to the challenges of a changing climate.

Grizzly bear stands on waterfall about to catch salmon in mouth

As the climate changes, animals will need to adapt and evolve if they are to survive. According to a recent study, scientists found that grizzly bears are choosing berries over salmon due to the warming planet, a choice that is tipping a delicately balanced ecosystem.

One consequence of global warming is an upended natural schedule. Elderberries, normally not widely available until late August and September, are now flourishing in early summer  the same time as when salmon swim upstream to lay their eggs, and unintentionally, start off the grizzly bear's long feast before hibernation.

Grizzly bears on Kodiak Island in Alaska are now forced to choose whether to spend their energy catching protein-rich fish or grazing on the elderberries filling the mountain, which allow them to gain weight more quickly.

"What you have is a scrambling of the schedule," William Deacy, a biologist who works at Oregon State University, told The Telegraph. "It's essentially like if breakfast and lunch were served at same time and then there is nothing to eat until dinner. You have to choose between breakfast and lunch because you can only eat so much at a time."

The impact the bear's new vegetarian diet has had on their surrounding habitat has been immediate. Scientists have already seen the forests surrounding the salmon streams struggle without the decaying carcasses to fertilize them. 

As the climate continues to change, elderberries are ripening about two and a half days earlier each decade, and they are expected to overlap with salmon season completely by 2070. According to The Telegraph, in the historically hot summer of 2014, bears were noticeably absent from their usual fishing grounds, and this is swiftly becoming the new normal. 

As the climate changes, so will nature's many interlocked systems with wide-reaching consequences. The adjustments may seem subtle — like a bear's switch to a vegetarian diet — but nature's rule has always been that subtle causes have huge effects.

Banner and thumbnail credit: Flickr user Scott Calleja

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