Posts Tagged ‘Pleistocene squirrels’

Colorful Fox Squirrels–Were they the More Common Squirrel in the Southeast During the Pleistocene?

July 5, 2012

The extinction of the megafauna saddens me.  America’s wilderness areas are devoid of mammoths, mastodons, ground sloths, and so many other animals, and an ungodly long drive is required to see the remaining species such as bison and elk, unless a person is lucky enough to live somewhere near Yellowstone National Park or in Alaska.  But at least squirrels and rabbits are still abundant in most places.  They are every bit as interesting as the extinct species of megafauna and during the Pleistocene the total biomass of smaller animals probably outweighted that of the larger beasts, so they were common then too.

Tree squirrels are relatively rare in fossil sites because they live in wooded habitats.  When they die, their bodies mix with acidic leaf litter which dissolves bones, if a scavenger doesn’t come along and munch them down first.  Thanks to predatory birds, squirrel fossils do occur in cave deposits.  Hawks and owls capture squirrels, carry them to roosting sites in caves, and often sloppily drop pieces of squirrel where the cave environment preserves them.  Yarbrough Cave in Bartow County Georgia yields the remains of 5 squirrel species–woodchucks, chipmunks, gray squirrels, fox squirrels, and 13-lined ground squirrels.  This cave deposit dates to the Last Glacial Maximum (~20,000 BP carbon date average based on 4 sample dates).  The variety of squirrels is evidence of a diversity of habitats.  Gray squirrels prefer young dense forests; fox squirrels like open mature woodlands; chipmunks inhabit boulder-strewn woods; woodchucks live in open meadows; and 13-lined ground squirrels are denizens of prairie.

Although Pleistocene environments in Georgia consisted of many constantly changing stages of succession, I think 0pen mature forests would have been the most common type.  Frequent fires, megafauna foraging, insect infestation, tree diseases, windthrows, and drought eventually convert dense young forests into open parkland environments with widely spaced large older trees lucky enough to survive the ravages of nature.  Gray squirrels are more common today in Georgia because young dense forests predominate, following the clear cutting of yesteryear.  These squirrels escape predation by jumping from tree to tree which is possible in forests with closely spaced trees, but bigger clumsier fox squirrels run along the ground to reach the safety of a tree.  They’re better adapted to open forests.  Therefore, fox squirrels may have been the more common squirrel of the late Pleistocene in the upper south.  (Fossil evidence suggests they didn’t arrive in Florida until very late in the Pleistocene.)

This fox squirrel was recently spotted in Ringgold, Georgia which is in the northern part of the state where fox squirrels are said to be rare to absent.  This proves they still live in this region.  The lady who took this photo didn’t know what this animal was and posted it online.  Notice to college biology students searching for a thesis idea:  No recent study has been conducted on fox squirrel populations in Georgia.

Mounted fox squirrel killed by a hunter in Georgia.  I lifted this and the following photos from the Georgia Outdoor News forum.  Check out their political forum.  They aren’t exactly open to progressive politics. 

Another mounted fox squirrel killed in Georgia by a hunter.  Note the orange color phase.  Fox squirrels in northeastern Ohio are orange but have no white marking on their nose.  Fox squirrels are locally common on the southeastern coastal plain.

 

 

Note all the color variations on these fox squirrels killed in just 1 locality on the South Carolina coastal plain.

In present day Georgia and South Carolina fox squirrels occur locally on the coastal plain.  They are reportedly rare to absent in the piedmont and mountains, though the the top photo proves they’re not extinct in the region.  In the southeast they seem to prefer open pine forests with a few oaks.  Curiously, in the midwest they’re restricted to hardwood forests.  On average they weigh twice as much as gray squirrels and come in a much greater variety of colors.

I grew up in Niles, Ohio, a small town in northeastern Ohio.  Big orange fox squirrels were the only kind of squirrel I ever saw there.  Our house was surrounded by an oak-dominated woods on 2 sides.  Unlike the orange color phase of southeastern fox squirrels, the ones in Ohio had no white marking on their nose.  I also saw gray and black fox squirrels at a park next to Niagara Falls.  In Georgia I’ve only seen a fox squirrel once.  It was a black one among a dozen gray squirrels poaching pecans in a Burke County orchard.  They are reportedly common on golf courses in the South Carolina coastal plain.  I haven’t seen a fox squirrel in 20 years.  I’m trying to determine how I can find some time to scope this species out on a beach trip next month.