by Eric Soehren, Elhew Field Station, State lands division OEHREN S C i R E SNAP! A look At AlAbAmA’S snapping turtles the southeastern united States is regarded as one of the world’s biodiversity hotspots. Much of this diversity is a result of the physiography of the region. Within the Southeast, Alabama is especially fortunate to have a tremendous wealth of aquatic taxa, including one of the highest diversities of turtle species. Of the 42 spe- cies occurring in the Southeast (from Virginia to Arkansas), 30 (71 percent) are found in Alabama. Of these, two of the most underappreciated and often confused species are the snapping turtles—the Alligator Snapping Turtle and the Common Snapping Turtle. Although similar in appearance, the demeanor and habits of the two species are different in many respects and are the focus of this article. 10 Outdoor AlAbAmA | July 2011 alligator snapping turtle (MacRochElyS temminckii) ERiC SOEHREN Thealligator snapping turtle is the pace referred to as “supramarginals” located Within these situations, they tend to favor largest freshwater turtle in North America. between the marginal (outer edge) and cos- places where there are submerged logs, root Adult males may attain weights over 200 tal (inner area) scutes, which is a diagnostic entanglements and snags. pounds (although extremely rare in the characteristic. This turtle is almost entirely aquatic wild), while females generally do not ex- Alligator snapping turtles are restricted in habit, only leaving the water to nest. ceed 50 pounds. Aside from its massive size to the river drainages that flow into the Mating takes place from February to at maturity, distinguishing characteristics Gulf of Mexico ranging from the Suwan- April with nesting occurring shortly af- include a very large, partially retract- nee River in north Florida west to the San terwards. Females seek the highest places able, triangular-shaped head tapering to Antonio River in Texas and northward near water such as overgrown sections of a prominently hooked beak (upper jaw), within the main channel and tributaries sandbars, natural levees and man-made three pronounced ridges extending down of the Mississippi River to southeast Iowa. spoil mounds. At nest sites, females will the carapace (top shell) prevalent at all ages, In Alabama, it occurs throughout the state excavate a flask-shaped cavity with their a long and muscular tail, a reduced cross- from the Tennessee River system south, hind legs and deposit a clutch of 30-40 eggs shaped plastron (bottom shell), and eyes with higher densities likely occurring in the on average. Only one clutch is laid each positioned along the sides of the head that Coastal Plain region. It is a denizen of slow- year or every other year depending on the are surrounded by a ring of small fleshy moving water bodies such as oxbow lakes, turtle’s physical condition. The eggs are projections. They also possess a unique set swamps and backwater sloughs often as- chalky white and nearly spherical. Incuba- of scutes (bony scales or plates) on the cara- sociated with large floodplain river systems. tion time varies with soil temperature and range between 79 to 110 days. As with the cross-shaped other turtle species, incubation tempera- plastron is a charac- ture influences gender, with warmer soil teristic of both the Alligator Snapping temperatures yielding female-dominated turtle (pictured) and clutches and cooler temperatures yielding Common Snapping male-dominated clutches. turtle. It is consider- Hatching takes place over several days ably smaller in size compared with other and the hatchlings are similar in appear- species of turtles in ance to adults. It takes over a decade for the Southeast. young to reach sexual maturity. Nests and hatchlings are susceptible to a variety of predatory mammals, reptiles, birds and large fish. Adults have no natural predators. Alligator snapping turtles are opportu- nistic foragers and will feed on a wide va- riety of plant and animal matter including carrion. It also forages using a specialized ERiC SOEHREN www.outdooralabama.com 11 worm-like appendage or “tongue” as a lure been fabled to snap a broom handle in half, spread harvest. Furthermore, other factors located at the base of its lower jaw. During which is an exaggeration. However, they may be contributing to its decline currently. these instances, it will sit motionless with can snap quickly and with considerable These include the use of baited limb lines, its mouth agape and wiggle the specialized force causing significant injury to those that trotlines, and hoop nets for fishing that are tongue to attract fish. When an unsuspect- are careless around them. not regularly attended. As opportunistic ing fish hits the lure, the turtle’s jaws slam Alligator snapping turtles have under- scavengers, they can easily be hooked or shut with great velocity enabling it to swal- gone severe population declines throughout trapped underwater placing them at risk low its prey whole. much of their range, primarily as a result of of drowning. Alligator snapping turtles can be very unmonitored commercial harvest support- Habitat degradation and pollution have sedentary and have been reported to ing the soup industry. During its peak in also been implicated in population declines. Collectively these threats are further ex- remain at one location for more than a the 1970s, many populations were exploited acerbated by this species’ life history traits month before moving. Alternatively, they by trappers well below sustainable levels, – slow to mature, low reproductive output, may move considerable distances within prompting the enactment of legal protec- and vulnerable to nest predation. These fac- river channels when food scents are de- tion in most states including Alabama (see tors, in addition to poorly understanding tected. When removed from water, alliga- Nongame Species Regulation 220-2-.92). many aspects of their biology, have resulted tor snapping turtles will remain in place Although commercial harvest is no longer in its recent designation of high conserva- and hold their jaws open and occasionally a serious threat in Alabama today, many tion concern in Alabama’s Comprehensive hiss. Although very powerful, their bite has populations have not recovered from wide- Wildlife Conservation Strategy. common snapping turtle (chElydra serpEntina) ERiC SOEHREN Common snapping turtles are large, from 10 to 75 pounds, but any individual moving long distances over land between semi-aquatic turtles recognized by their exceeding 40 pounds in the wild is quite water bodies. large, rounded and fully-retractable head, unusual. Although males grow larger than Common snapping turtles are opportu- elongated neck, powerful jaws, relatively females, both sexes are nearly indistin- nistic foragers and will feed on a diverse ar- broad and flat carapace, long and knobby guishable except that the cloaca (cavity in ray of plants and animals and are especially tail, and sturdy legs with formidable claws. the pelvic region) of adult males extends adept at scavenging. They are maligned by The scutes along the posterior end of beyond the carapace edge. many anglers due to the misconception that the carapace are strongly serrated (saw- As its name implies, the common snap- they are detrimental to sport fish. Although ping turtle is one of the most widespread toothed) and the plastron is small and they maneuver well in water, they are un- cross-shaped. Their eyes are positioned turtles in North America occurring just able to subdue most healthy fish; rather toward the top of the head. The carapaces about everywhere east of the Rocky Moun- they pursue sick, injured or dead fish and of hatchlings and juveniles are knobbed tains. It is so abundant that it has been may occasionally hit a baited hook. They (tubercle-shaped) giving a three-keeled found in nearly all freshwater habitats (e.g. appearance, but become smoother with rivers, creeks, marshes, swamps, reservoirs, may also use the “sit-and-wait” tactic to age and almost completely smooth in old farm ponds, vernal pools, ditches, etc.) ambush unsuspecting prey. individuals. Additionally, they are almost throughout from sea level to elevations ex- Mating begins in late winter and contin- always found with leaches attached to their ceeding 6,500 feet. Much of its widespread ues through early spring. During May and bodies. Recorded weights of adults range distribution can be attributed to its habit of June, females typically seek open areas near 12 Outdoor AlAbAmA | July 2011 water to lay eggs, but may be respected. If necessary, the safest way travel considerable dis- to carry a common snapping turtle is by tances over land to nest. firmly grasping its hind legs and insuring Clutch sizes usually range that its head is away from one’s body at all from 20 to 40 spherical times. Although once advocated, holding eggs, but may exceed them by the tails can cause serious injury 100. The incubation to their lower vertebrae and should never period varies from 55 be done. to 100 days depend- In Alabama, common snapping turtles ing on location with with carapace lengths between 4 and 12 some nests over- inches are protected by Nongame Species OEHREN S wintering as a result Regulation 220-2-.92 (3). Nevertheless, C i R E of colder climates adults are occasionally harvested by hu- or late nesting. Nests mans for their meat, which subsequently common and hatchlings are vul- may affect local populations. Moreover, snapping nerable to predation from they are often casualties of human persecu- turtle a variety of carnivorous mam- tion for a variety of unsubstantiated rea- mals, reptiles, birds and large fish. sons. Many are also killed by automobiles When threatened, adults are com- as they cross roads to reach nesting sites or bative and will snap rapidly and repeatedly adjacent wetlands.