Wednesday, June 15, 2016

Snapping Turtles on Land - Why?

June hereabouts brings turtle sightings on dry land, near and not so near bodies of water, some of which end up in the weekly newspaper police reports. What's happening is that female snapping turtles are leaving ponds and rivers to find places to lay eggs.

Let's get to the important parts first: snapping turtles should not be picked up by their tails as this can damage the animal's vertebral column and tail. Think how you would feel if dangling from one wrist or one ankle. And if you try for a grab of the shell, know that the neck is long enough and flexible enough for the biting end to reach at least half way back. A shell grip above the hind legs is safer, but better to leave the turtle alone. Second option is to lay a tarp or blanket on the ground and convince the turtle to walk onto that. (Yeah, right.) Then have people lift it by the corners. Or coax the turtle to walk into a garbage can.    

What these wanderers seek is a sandy or loose-soil bed in which to scrape out a depression, lay some 20 to 40 roundish eggs, each not much smaller than a ping-pong ball, scrape dirt back over, and depart. Unlike alligators or crocodiles, the mother does not guard and maintain the nest, nor stay with the newborns after hatching. Nest predation by skunks, raccoons, opossums and mink, followed by hatchling predation by great blue herons, snakes, otter... mean that fewer than five percent make it to end of first year.  

If they do survive, juvenile and adult snapping turtles are omnivores that will eat just about anything, including aquatic plants, dead fish, and live stuff they catch: crayfish, snails, fish, frogs, salamanders, insects, leeches, worms, snakes, small mammals, baby ducks, baby geese - and other turtles.

Females reach sexual maturity at about 15-20 years, with an upper shell 10-14 inches in length and a weight of 10-16 pounds. Males are larger than females. As snapping turtles continue to grow as they get older, and can exceed 50 years in the wild, male turtles can exceed 30 pounds, with rare reports of turtles exceeding 60 pounds. And there are reports of snapping turtles grabbing a leg of a adult Mallard duck and dragging the duck underwater.

One acquaintance told me of a childhood experience when he and friends were stepping on stones to cross a small stream in Great Meadow, Concord. One of the algae-covered 'stones' started to move! Everyone was startled. No one (and no turtle) was injured.   

Most snapping turtles enter hibernation by late October and emerge around April. To hibernate, they burrow into the debris or mud bottom of creeks, ponds or lakes. Metabolic rate is slowed. Rather than rising to the surface to breath, the semi-comatose turtles are able to absorb oxygen through their skin. Come spring the turtles reactivate. This paragraph started with "Most" because there are credible reports of sightings of active snapping turtles in mid-winter, seen through the ice.    

Female snapping turtle laying eggs, June 2015
Click on photo to enlarge.
Last June a snapping turtle larger than a car's hubcap chose the greenspace behind Maynard's town building to lay eggs. This was noted by town employees. A hurried consultation led to the conclusion that the eggs were too fragile to relocate, so a plastic mesh fence was erected around the nest site. The hope was that some 60-90 days later, unseen by human or predator eyes, the newly hatched, inch-long turtles crept under the edge of the fence, to the Assabet River, there to avoid herons and other hazards, and reach adulthood.

And finally, it is legal to catch snapping turtles in Massachusetts. From Mass.gov: "Common snapping turtles (Chelydra serpentina) that measure at least 12 inches in straight-line carapace length may be taken by hand, dip net or gaff, up to a limit of 2 per day, or in possession for personal use, by licensed fishermen. Snapping turtles may not be taken from May 1 to July 16." As to why one might want to catch a snapping turtle, the operative word is "soup."

EXTRA INFORMATION

Serpentina in the Linnaean name comes from observation that the neck is snake-like long and snake-like fast. Extended, head and neck are about same length as the width of the shell. Many the person has had a finger bitten for not knowing this fact.

Snappers hiss. If confronted on land, snappers expel air from their lungs to make more room to pull neck into shell. From this neck-retracted position the neck muscles and bones are ready for a very fast strike and bite.

Each state has its own restrictions. For example, Connecticut allows five per day, 30/year, shell length to exceed 13 inches, and allows hook fishing and turtle traps in addition to by hand, net or gaff.

Southeastern states are home to alligator snapping turtles, an entirely different species that weighs in at 100-200 pounds. This is the turtle that has an extension on its tongue that looks like a wriggling work. Fish swim up to eat it and become eaten.



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