The story of Arctic greening has overlooked some main characters. At center stage are climate change and warming temperatures. Meanwhile, large grazing wildlife, such as caribou and muskoxen, also play a key role in the timing and abundance of Arctic plants, according to a study from the University of California, Davis.

Dozens of Alaska’s most remote streams and rivers are turning from a crystal clear blue into a cloudy orange, and the staining could be the result of minerals exposed by thawing permafrost, new research in the Nature journal Communications: Earth and Environment finds.