There are just three western gray squirrel populations left in Washington state as more frequent and intense wildfires continue to decimate their habitats, officials said.
The idea that the driver of this decline is hot and dry weather seems dubious when the species is doing better in the warmer and drier states of Oregon and California.
I think habitat loss is the main issue here. This species mainly inhabits areas with closed canopy of large, mature pines and oaks. These species are less common in Washington which may explain their tenuous status there. Climate change may actually cause pine and oak to expand in Washington, which could even be beneficial compared to traditionally abundant conifer forest.
The hot and dry is a considerable contributor to the habitat loss though, from fires and disease. While tree species better adapted to those conditions may eventually come in, that is still habitat loss for a time to the squirrels.