Alaskan grizzly bears are choosing berries over salmon because of climate change, scientists have found.
A recent study in the Proceedings of the National Academy of Sciences analysing the bears of Kodiak Island in Alaska found that the bears are changing their diets.
Berries are ripening earlier than usual - at the same time freshwater streams are brimming with salmon.
William Deacy, a biologist at Oregon State University, told The Telegraph this resulted in a "scrambling of the schedule" for the bears.
"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 study found that the bears avoided the streams during the unusually hot summer of 2014, a time when they would traditionally kill up to three quarters of the salmon.
Instead the bears could be found in the hills eating red elderberries, which contain less protein than salmon and take less energy to break down, resulting in quicker weight gain for the bears.
This change in diet is harming the bears' natural environment: the lack of fish carcasses in the surrounding forest areas meant the soil was not as enriched with nutrients as usual.
This relatively small change could have a huge impact on the ecosystem, and while the Alaskan grizzlies might be able to cope, bears with a more limited food supply could be in trouble, Mr Deacy said.
Biologists have warned that climate change is behind the bears' dietary change.
Warming temperatures mean red elderberries are ripening two and a half days earlier every decade on average. If this pattern continues they will regularly overlap with the salmon by 2070, which could have devastating results for the Alaskan bears' ecosystem.