ALLIGATOR SNAPPING TURTLE
Kansas Species in Need of Conservation (SINC)
Alligator Snapping Turtles are the largest freshwater turtles. They weigh between 155 and 175 pounds (70 to 80 kg). They are characterized by three large, pronounced ridges, or keels, that run from the front to the back of the carapace. With powerful jaws and a large head, they are unique among snapping turtles for having eyes on the side of the head. The alligator snapping turtle looks very primitive and has been called the dinosaur of the turtle world.
It is a larger and slightly less aggressive relative of the Common Snapping Turtle. While the Common Snapping Turtle has a rather rounded smooth carapace, the Alligator Snapping Turtle's shell has three large, pronounced ridges running front to back across its massive shell. These ridges are very pronounced even in hatchling specimens, which also have a tail that is almost as long as the carapace itself. Additionally, the Alligator Snapping Turtle possesses a more pointed snout and a less-toothed tail, than its more common cousin.
The Alligator Snapping Turtle is known from the Neosho, Verdigris, Walnut, and Arkansas River Basins in Kansas from 1885 to 1986. Records from Woods and Kay counties in Oklahoma indicate that this species also is present in the Cimarron River and Arkansas River drainages, respectively.
County Breakdown: County Name (# occurrences)
Butler (1), Cherokee (2), Cowley (1), Labette (2), Lyon (1), Marion (1), Montgomery (1), Neosho (2), Sedgwick (1)
During reproduction, the male alligator snapping turtle mounts the back of the female. He grasps her shell with all four of his feet and inseminates her. It is unlikely that females reproduce more than once a year, and some females lay eggs in alternate years.
The turtles mate in early spring in Florida and late spring in the Mississippi Valley. They nest about two months later in a nest about 160 feet (50 m) from the shore. All nests are dug in the sand and clutch success is highly variable. A clutch may contain eight to 52 eggs and incubation takes 3.5 to 4.5 months. Hatchlings, therefore, emerge in the fall.
The sex of the hatchling is determined by incubation temperature and the hatchlings look very much like adults. Sexual maturity occurs in 11 to 13 years.
Evidence of reproduction has not been reported in Kansas.
Alligator snapping turtles spend most of their time in the water, and generally only nesting females venture on land. However, males have been known to bask. They are solitary, and there is very little social structure or parental care. The turtles stay submerged for 40 to 50 minutes at a time, and only go to the surface for air. They are so motionless under water that algae may cover their backs and make the turtles almost invisible to fish.
They generally live in the deep water of large rivers, canals, lakes, and swamps. Hatchlings and juveniles usually live in small streams.
The alligator snapping turtle is both a scavenger and an active hunter. It most actively forages for food during the night. During the day, it usually lies quietly in the bottom of a dark body of water and opens its jaw to reveal a small pink worm-like lure in the back of its gray mouth. The lure attracts fish, and when the fish enter the jaws, they are either swallowed whole, sliced in two by the sharp jaws, or impaled on the sharp tips of the upper and lower jaws. The alligator snapping turtle eats any kind of fish and also eats frogs, snakes, snails, worms, clams, crayfish, aquatic plants, and other turtles. The turtles feed year round by taking advantage of warm winter days to search for food.
Predators and Defense:
Adult Alligator Snapping Turtles have no natural enemies. The eggs and hatchlings (through the first five years) may be consumed by a variety of fish, reptiles, other turtles, birds, and mammals.
The greatest threat to their continued existence is the alteration of their riverine habitats. Channelization and dam construction are two common practices that eliminate habitat and reduce movements.
Growth and Longevity:
Alligator Snapping Turtles are massive and have been documented as weighing in at well over 200 pounds, with a shell length of 79cm (31 in) and heads as large as 24 cm (9.5 in). There is marked sexual size dimorphism exhibited in this species, with males growing nearly twice as large as females.
KU 204150, Lyon County, Rick Christie and J. M. McDaniel, 21 February 1967, carapace length 558 mm (22 inches), Collins (1993).
MHP 9597, a specimen (image above) from Labette Creek in Labette County, Kansas was collected in April 1938 by Jack Gearhart, Ralph Stice, and Henry Stice. This specimen was reported to weigh 132.5 pounds.
There is an unverified legend that a 403-pound (183 kg) alligator snapping turtle was found in the Neosho River in Kansas in 1937.
Not known from Kansas.
Listed as a Kansas Threatened Species in 1978, populations are now considered Kansas Species in Need of Conservation (SINC). The lack of evidence for a reproducing populations and the insufficient overall documentation in Kansas, is cited as the reasoning behind the decline in status (Shipman et al., 1993; but see Capron, 1975). Based on all accumulated data, Kansas specimens are best considered as transients, with insufficient populations and/or conditions to successfully reproduce.
There has already been considerable effort by many knowledgeable individuals (Irwin , Capron [1975, 1986, 1987], and Shipman ) to assess the distribution and status of this turtle in the state. Capron (1986) noted the rapid and extensive movements (usually at night) of the specimen he was radio-tracking, indicating that individuals may be capable of substantial dispersal over their lifetime.
This turtle currently is known in Kansas only from five vouchered specimens collected in the Neosho River, Verdigris River, and Walnut River watersheds in southeastern Kansas from 1885 to 1986. Records from Woods and Kay counties in Oklahoma support the literature records for the Arkansas River drainage in Hall and Smith (1947) and indicate that this species may ultimately be discovered in the Cimarron River drainage system.
Capron (1986) described the habitat of the collection site of the only recently known specimen in Montgomery County, of being mud bottomed and with numerous pools reaching depths of six feet at normal stream levels. Many deadfalls, log jams, and pockets of leaf litter were noted at the site as well. The stream was almost completely shaded by the canopy of adjacent trees. The Spring River and Shoal Creek were evaluated as to their capacity to support this taxon, but was felt to be sub-optimal, (Capron, 1986). Capron (1986) remarked that pollution and the obstruction of low-water dams as likely reasons for the scattered low-density populations that exist in Kansas.
Shipman et al. (1993) radio-tracked the same turtle as Capron, in an effort to better characterize utilized habitat types, determine growth rates, and acquire diet information. They noted that all long-term movements of the turtle over their study were upstream, while short-term movements were not always directed upstream. Short-term movements could be substantial though, as evidenced by a movement that covered 227 meters in less than one hour. All movements were at night. Optimal sites were shown to consist of an overhead canopy, accumulated detritus, muddy substrate, and pools. Shipman et al. (1993) reported an attack by the Alligator Snapping Turtle they were tracking upon two Common Snapping Turtles.
Pritchard (1989) hypothesized that Alligator Snapping Turtles in the northern parts of their range, are older individuals. He postulates that once born, this species continually travels upstream. This hypothesis was further supported by the study of Shipman et al. (1993). however a rigorous field test is warranted. If correct, the implications with respect to the numerous low-water overflow dams and low-water bridges in southeast Kansas may (as Capron, 1986 surmised) be insurmountable barriers to currently migrating individuals and inadvertently trapped existing populations.
1886. Cragin, F. W. Miscellaneous notes. Bulletin Washburn Laboratory of Natural History. 1(7): pp. 212.
1947. Hall, Henry H. and Hobart M. Smith. Selected records of reptiles and amphibians from southeastern Kansas. Transactions of the Kansas Academy of Sciences. 49(4): pp. 447-454.
1960. Legler, John M. Distributional records of reptiles and amphibians in Kansas. Transactions of the Kansas Academy of Science. 63(1): pp. 40-43.
1981. Clarke, R. F. A record of the Alligator Snapping Turtle, Macroclemys temminckii (Testudines: Chelydridae). Transactions Kansas Academ of Science. 84(1): pp. 59-60.
1985. Irwin, Kelly J. Distribution, abundance, and habitat preference of the alligator snapping turtle in southeastern Kansas. Kansas Fish and Game Commission. Contract 50 Final Report: pp. 43.
1986. Capron, Marty. A radio telemetry study of an adult alligator snapping turtle in Kansas. Kansas Fish and Game Commission. Final Report: pp. 14.
1987. Capron, Marty B. A study to determine the current presence and numbers of the Alligator Snapping Turtle at selected localities in southeastern Kansas. Kansas Department of Wildlife and Parks, Agency Contract No. 153. Pp. 14.
1991. Shipman, Paul A., David R. Edds, and Doug Blex. Report on the recapture of an Alligator Snapping Turtle (Macroclemys temminckii) in Kansas. Kansas Herpetological Society Newsletter. 85: pp. 8-9.
1993. Collins, Joseph T. Amphibians and Reptiles of Kansas. University Press of Kansas, Lawrence, Lawrence. Pp. 397.
1993. Shipman, Paul A., David R. Edds, Lenn E. Shipman, and Doug Blex. Alligator Snapping Turtle (Macroclemys temminckii) habitat selection, movements, and natural history in southeast Kansas. Kansas Department of Wildlife and Parks, Agency Contract No. 279. Pp. 91.
2005. Riedle, J. Daren, Paul A, Shipman, Stanley F. Fox, & David M. Leslie, Jr. Status and distribution of the Alligator Snapping Turtle, Macrochelys temminckii, in Oklahoma. Southwestern Naturalist. 50(1): pp. 79-84.