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THIS WEEK at HILTON POND
1-7 October 2004
Installment #241---Visitor #
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THE SLOW-PACED BICYCLIST Aside from taking photographs, banding birds, and playing Frisbee with an old Newberry College roommate, our favorite outdoor activity is going on leisurely bicycles rides. As cycling purists, we stick to biking asphalt highways, having always believed that woodland walking trails should be the domain of slow-moving hikers and nature watchers rather than mountain bikes and all-terrain vehicles. In the old days, we pedaled every morning from York to a teaching job 10 miles away in Rock Hill, and for several years even made a self-propelled 36-mile round-trip to and from Fort Mill High School. In addition to clearing our mind and making us feel good physically, bicycling around York County has always given us the opportunity to see many things never noticed by folks whizzing past in their automobile cocoons--certainly the case this week as we returned from a late afternoon ride. Shortly before we started gearing down to enter the driveway at Hilton Pond Center, we saw movement on the road ahead of us, and screeched to a halt as a small creature crawled across the center line. It was a just-hatched Common Snapping Turtle (below), and it was moving slowly but intently from west to east across the highway, oblivious to dangers it faced from passing traffic. All text & photos © Hilton Pond Center We hopped off the bike quickly--frantically waving for an oncoming car to slow down. Fortunately, the driver WASN'T talking on a cellular phone and WAS paying attention to her driving, so she braked and rolled safely to a stop. As we reached down to grab the turtle, the driver realized we were on a mission of mercy and smiled as she yelled out her window: "Go, turtles!" What a far finer attitude that was than the one demonstrated by folks who intentionally speed up and run over all sorts of defenseless wildlife as it wanders across our highways. We cupped the tiny turtle in our left hand, re-mounted our bike, waved farewell to the automobilist, and pedaled the final 300 yards to Hilton Pond Center, where we temporarily transferred our reptilian prize to a bowl of water. Had it been an Eastern Box Turtle or larger snapping turtle, we simply would have moved it to safety on the grassy shoulder and then been on our way. We decided, however, that this hatchling needed some help, especially since it was heading due east and the closest body of water in that direction was a mile and a half away across three paved roads--a dangerous route at best. We suspect this particular turtle hatched from a nest near a small impoundment about a quarter mile north of Hilton Pond Center and directly opposite the turtle's direction of movement; its parents may even have come from Hilton Pond itself. Common Snapping Turtles, Chelydra serpentina, take their scientific name from a long, snake-like neck (above) that stretches out surprisingly far as they snap at food and potential predators. Those found in rivers and large ponds in the U.S. and southern Canada from the Rocky Mountains to the Atlantic Coast can become real whoppers, but they all start out as embryos inside spherical white eggs about the size of ping-pong balls. A particularly large adult can reach 70 pounds or more and have a carapace (top shell) up to 18" long, but a typical mature individual is only about half that size. The Alligator Snapping Turtle, Macroclemys temminckii, grows bigger still and is, in fact, the largest freshwater turtle in the world; the record documented specimen is a 236-pound captive in Chicago's Brookfield Zoo, but it's more common for wild Alligator Snappers to weigh less than 175 pounds. Alligator Snapping Turtles occur across the southeastern U.S., primarily in Florida and the Mississippi River Valley. In summer, we swim frequently in Hilton Pond and can deal with the thought of 30-pound Common Snapping Turtles sharing the water, but we're not sure we'd EVER dive in if we knew a 200-pound Alligator Snapper was lurking in the depths. Both snapping turtles species do indeed hang out on the bottom in their aquatic habitats, where they mainly play the role of scavenger--eating pond or river dwellers that already have met their demise. Common Snapping Turtles also consume unwary fish and various invertebrates; Alligator Snappers even have a fleshy protuberance in their mouths that acts as a lure for live prey. Sometimes snapping turtles play havoc with waterfowl populations, as we know firsthand from watching a snapper poke its snout above the water's surface just behind a raft of newly hatched Wood Ducks. A moment later, there was one less duckling, but the hen rallied the rest of her progeny and shooed them toward shallower water where the predatory turtle couldn't follow. By late spring or mid-summer, fertile female Common Snapping Turtles leave the safety of their ponds and go ashore to lay eggs (above left). They often walk surprising distances, searching about for who-knows-what special characteristic they desire in a place to lay their clutch. Some gravid females are hit by cars, smaller ones may be taken by hawks, and in many parts of the country turtle soup aficionados stand ready with washtubs they can throw over the wandering reptiles. Despite these dangers, the female that manages to find her special spot moistens the soil with her urine, excavates the nest hole with her hind legs, lays a clutch of leathery eggs, and then smooths out the area by sliding across it repeatedly with her lower shell (plastron). We once spent several hours watching and photographing a female snapper go through this whole process in the flats below Hilton Pond, only to return the next day to find that all her efforts had been negated by a hungry Raccoon with a taste for fertilized turtle eggs (above right). In young Common Snapping Turtles that hatch and survive, the inch-long carapace is rather rough (below), with large serrations on the posterior end; in adults the upper surface is quite smooth, as shown in the photo above of the egg-laying female. A snapping turtle's legs are rather short, with heavily webbed toes--five on front feet and four behind--that help it ply the water efficiently. The tail is extremely long and thin but thickens considerably with age, eventually providing the only safe handle for holding an adult snapper; it's also the prime ingredient in snapping turtle soup. Incidentally, you'll notice that the baby turtle's head and tail (below) have a rusty appearance; this is a film of red clay that adhered as the turtle hatched and dug its way out of a subterranean nest chamber.
Unlike box turtles that can pull in all their appendages and shut their shells completely, Common Snapping Turtles have no such defense. The carapace barely covers the body, and the plaston is very small (below); a cross-shaped central shell protects the internal organs, but most of the legs and neck are accessible if a predator flips the snapper on its back. In very young turtles like the one pictured here, the center of the plaston shows a longitudinal scar; this is where the yolk was attached to the developing turtle and is analogous to the "belly button" of a mammal.
Despite their "incomplete" plastron and relative lack of a passive defense, not much messes with adult Common Snapping Turtles. They are aggressive, stand their ground--even lunging at much larger enemies--and stories of big snappers being able to take off a human finger are undoubtedly true. Baby turtles are less aggressive and lead a much more dangerous existence; many are swallowed by everything from Largemouth Bass to River Otters to Great Blue Herons. We also suspect adult snappers are not above cannibalizing their smaller relatives. Thus, in our judgment, these baby Common Snapping Turtles need all the help they can get, so we were more than happy to pause our bike excursion this week to help the hatchling that was trying to cross the road. We don't know if it will stay, but we released our little turtlet this week into Hilton Pond, where it immediately dived to the murky bottom and disappeared from view. We just hope this slow-moving creature won't grow up to nibble our toes as we swim and cool down from one of our slow-paced, nature-watching bicycle rides.
All text & photos © Hilton Pond Center
Comments or questions about this week's installment? NOTE: Be sure to scroll down for an account of all birds banded or recaptured during the week, as well as some other interesting nature notes. "This Week at Hilton Pond" is written & photographed You may wish to consult our Index of all nature topics covered since February 2000. You can also use the on-line Search Engine at the bottom of this page. For a free, non-fattening, on-line subscription to "This Week at Hilton Pond," just send us an E-mail with SUBSCRIBE in the Subject line. Please be sure to configure your spam filter to accept E-mails from hiltonpond.org.
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SPECIES BANDED THIS WEEK: * = New species for 2004 WEEKLY BANDING TOTAL YEARLY BANDING TOTAL BANDING GRAND TOTAL
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NOTABLE RECAPTURES THIS WEEK Tufted Titmouse (2) OTHER SIGHTINGS OF INTEREST
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Hilton Pond Center for Piedmont Natural History is a non-profit research & education organization in York, South Carolina USA; phone (803) 684-5852. Directed by Bill Hilton Jr., aka The Piedmont Naturalist, it is the parent organization for Operation RubyThroat. Contents of this Web site--including articles and photos--may NOT be duplicated, modified, or used in any way except with the express written permission of Hilton Pond Center. All rights reserved worldwide. To obtain permission for use or for further assistance on accessing this Web site, contact the Webmaster. |