Squirrels beat the heat

Canadian squirrels have evolved earlier breeding times.

Squirrels with genes for earlier breeding were probably favored because this allows them to take advantage of an earlier spring and hoard more pinecones for winter survival

…..as the climate has warmed in recent decades, Canadian squirrels have evolved shifts in their breeding times that make them more successful in warmer climates.

Berkeley University: Understanding Evolution, May 2009