Common Snapping Turtle {Chelydra serpentina) 



Description: The Common Snapping Turtle appears too large for its shell. The upper shell is 

 olive-gray, or brown to black with the posterior edge very serrated; it has three low keels with 

 protrusions positioned on each scute (a scale-like plate on the shell). The much-reduced 

 lower shell is cream-colored. A long, keeled tail and warty tubercles on the head and neck are 

 distinguishing characteristics. Males average about 10-20% larger than females, and have the 

 anal opening posterior to the rim of the upper shell (Ernst el al. 1994). Most aduhs range 

 from 13-30 pounds in Montana, the largest known Montana specimen was a 47-pound male 

 (Reichel and Flath 1995). 



Eggs and Young. The spherical, white, tough-shelled eggs are about 23-33 mm in diameter 

 (Ernst et al. 1994). They typically number 20-40 per clutch (Ernst et al. 1994). Coloration of 

 young turtles is similar to adults and the upper shell is 24-3 1 mm long. 



Similar Species: None. 



Habits and Habitat; Snapping turtles occur in stock ponds, reservoirs, sloughs and backwaters, 

 rivers, irrigation ditches, and slower-moving streams, such as Otter Creek in Powder River 

 County (Hendricks and Reichel 1996). They prefer waters with a soft mud or sand bottom, 

 and much aquatic vegetation or debris (Ernst et al. 1994). They do occasionally move 

 overland, but are found doing so less frequently then Painted Turtles. Food is mostly animal 

 matter. In the north it is most active in the morning and evening (Ernst et al. 1994). Adult 

 females first breed at 12-19 years of age in Michigan and Ontario (Ernst et al. 1994). Eggs 

 are laid in nests excavated in sandy or gravelly areas or muskrat houses in late spring or early 

 summer. Sex is determined by the temperature of incubation (Ernst et al. 1994). Hibernation 

 is in soft bottoms, under cut-banks, or among submerged roots. Snapping Turtles have a 

 reputation for an evil temper, and are quick to bite. They can be handled safely if carried by 

 the tail with the upper shell a\i'ay from the captor. 



Surveying: Although various turtle traps can be used for surveys, visual identification is suitable 

 for presence/absence studies since the three turtle species in Montana are easily distinguished. 

 Surveys should be done on sunny days with a pair of binoculars. During cold or cloudy 

 weather, turtles tend to remain underwater for long periods and can be missed on a walk- 

 through survey. 



Status and Distribution: Common Snapping Turtles occur in the Yellowstone River downstream 

 from Billings, the Missouri River downstream from Ft. Benton, and probably all tributaries 

 (such as the Tongue River) with suitable water. There are no records downstream from Ft. 

 Peck Dam. They also occur in water bodies that can be reached by a short trek across land. 

 Eastern Montana records are few, widely scattered, but mostly concentrated in the coal 

 country of Rosebud and Powder River counties. Some snapping turtles are caught with 

 fishing tackle. Concentrated unregulated harvest could be detrimental to local populations. 

 Although not encountered in 1998, it is probably more abundant and widespread in eastern 

 Montana than records indicate. For example, there are no records in the MTNHP database 

 for Wibaux County, but a local farmer said they are resident in Beaver Creek south of Wibaux 

 (pers. comm. 1998). It should be watched for particularly in ponds, streams, and rivers; any 

 animals located on BLM lands should be documented. 



Montana Natural Heritage Program rank: G5 S3. Species of Special Concern, BLM Special 

 Status Species. 



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