Biodiversity happens when an ecosystem brings competing species to a stalemate: all have their niche, all get by, none can completely suppress another. Global warming doesn't so much tip this finely wrought balance in the Crown one way or another as knock it all down: no niche wins out; the real winners are the species that don't have a niche. These are the ones who don't have to change their genes. Grizzly bears may be the world's least choosy eaters, omnivores par excellence that can live on anything and learn what they need to survive. Wolves, mountain lions, and coyotes are also versatile generalists. Populations of these animals have become more and more robust in the Crown, and so long as they avoid getting shot by people, they will live just as well in an ecosystem restructured by climate change.
So across the current range of species in the Crown "there's going to be a shakeout," says Fagre, "because some will be able to adapt better than others. The ability to change your behavior will be really important." Species that are "hard-wired" to live a certain way—hares who change color for winter, or bull trout that only spawn in clean, icy waters—will be hard-pressed to do things differently in their lifetime.