These squirrels are hybrids of two species, the northern flying squirrel and the southern flying squirrel. As the names suggest, the northern flying squirrel is native to northern regions of the United States into Canada, while the southern flying squirrel is found further south in the United States. The northern flying squirrel is larger, and has a gray and white belly, while the smaller southern flying squirrel has an all-white belly. Hybrids between the two are the size of the southern flying squirrel, with mottled gray and white belly fur.
|A northern flying squirrel visiting a|
Recently, scientists in Ontario, Canada have discovered an increasing number of hybrids of the two species. Ontario is within the range of the northern flying squirrel, but is well to the north of the usual range for the southern flying squirrel. Researchers including Jeff Bowman theorize that warming temperatures are driving some species, including the southern flying squirrel, farther to the north, so that the ranges of these two species now overlap more than they did in the past. A recent survey found that around four percent of flying squirrels in Ontario are now hybrids.
|A southern flying squirrel|
This is certainly not the first example of hybridization between species. The story cites the example of cross-breeding between grizzly bears and polar bears, which may also increase with the effects of global warming. But Bowman and other scientists believe that the flying squirrels are the first documented case of a hybrid species specifically caused by human-generated climate change. It is not clear what the long-term impact of hybridization might be for the flying squirrels or other species. Might a new flying squirrel species created by cross-breeding be better adapted to deal with a warmer climate? It's too soon to tell.