Map Turtles Versus Red-eared Sliders

     Interestingly to me, map turtles and red-eared slider turtles live inland in Lancaster County, Pennsylvania, though they both seem out of place here.  Map turtles are a river species, living in river systems in the United States, including the Susquehanna along this county's western border.  Red-ears, which are a race of yellow-bellied sliders, and have a red bar on each side of their necks when younger, are originally from ponds, ditches and slower parts of creeks in The South and the Mississippi River watershed. 
     The Conestoga, which is a small river flowing across the length of Lancaster County and a tributary of the mile-wide lower Susquehanna River, has map and red-eared turtles living in it.  The red-ears were introduced to this county by people who bought baby pet turtles from local pet shops, but later released them into the Conestoga, and some creeks and human-made impoundments in this county.  Many of those red-ears grew up and reproduced, establishing themselves in the wild here, as in much of the United States outside their original range and other parts of the world.  But the Conestoga River is the only waterway in this county where I have seen both map turtles and red-eared turtles. 
     These species of turtles have similarities.  They both can have upper shells up to a foot long at maturity.  Maps and red-ears certainly are bigger than the native pond turtles called painted turtles. Maps and red-ears are both green-brown for camouflage in the water and when sunning themselves on half-submerged rocks, and logs fallen into the water.  Some of them are partly covered with mud or moss, which also blends them into their background.  They usually are difficult to see, in the water and out of it.  Few people know they exist at all in Lancaster County. 
     Both these turtle species have yellow stripes on their heads, necks and legs, which are best seen on younger individuals.  Young map turtles have yellow markings on their upper shells that remind one of a map, hence their common name. 
     Both kinds of turtles are shy, and quick to plunge into the water at the slightest hint of danger.  And they both eat snails, small clams, crayfish, aquatic insects, tadpoles, carrion and water vegetation, all of which is easy for them to seize from the bottoms of the waterways and impoundments they live in.  However, these two species might be in direct competition for food, and living space, with each other: But perhaps not.  Only time will tell which species gets the upper hand, if either one.   
     Map turtles and red-ears are not seen much, except when sunning themselves, which they do a lot during spring, summer and fall.  Like many kinds of aquatic turtles, they crawl out of the protective water onto rocks and logs to bask in the hot sunlight, which warms them and speeds their  metabolism, as it does other kinds of reptiles, so they have the energy to hunt food.  The heat of the sun also kills some aquatic parasites on their bodies.
     Like all cold-blooded creatures this far north, map turtles and red-ears hibernate in the mud in the bottoms of their watery homes through winter.  Then their metabolism is very slow.  They need little oxygen, eat nothing and take in oxygen and release carbon dioxide into the water through thin tissues of their bodies.  But the warmth of the next spring, awakens them for another year of eating, growing and reproducing.