Common Musk Turtle (Sternotherus odoratus)

Photos by J.D. Willson unless otherwise noted

Description: Common musk turtles are small turtles (2 – 5 in; 5-12 cm) with dark brown or black shells that may be streaked or mottled and commonly accumulates green algae. There are two distinct stripes on the head and barbels on both the chin and throat. This species can be differentiated from the similar mud turtles (Kinosternon sp.) by their relatively small plastron (bottom of shell), which has one weak hinge and exposed areas of skin between plastron scutes. Loggerhead Musk Turtles (Kinosternon minor) have much larger heads, with no slight stripes. Males have thicker tails than females. Additionally, males’ tails always ends in a spine and the anal vent extends beyond the edge of the carapace.

Range and Habitat: Common musk turtles occur throughout the eastern U.S. in a variety of aquatic habitats. They are most common in shallow water-bodies with low currents, abundant aquatic vegetation, and soft organic bottoms.

Habits: Musk Turtles are primarily nocturnal and they are often seen foraging in shallow water in the evening. They are omnivorous (e.g., seeds, insects, snails, tadpoles, algae) and will occasionally scavenge on fish carrion. This species rarely emerges to bask and is most successfully captured with nocturnal trapping techniques. Musk turtles climb surprisingly well and occasionally rest fairly high in trees. Breeding occurs in the spring and fall. Mating often occurs in the water and males bite the female to see if she is receptive before mounting. Females often lay two clutches a season of 1-9 eggs under debris in loamy soils. Clutch size varies with carapace length and age, but environmental factors could be the primary influence. There is geographical variation with time of reproduction and clutch size. Nesting aggregations are occasionally observed. Male-biased sex ratios are observed consistently across populations. This species over-winters in the debris and mud under water. The name “stinkpot” is appropriately assigned due to phenolalkalinic acid excreted from glands that creates a pungent musky odor. Females reach sexual maturity at 8-9.5 cm (~ 4 yrs) and males at 6-7 cm (~ 2 yrs).

Conservation Status: The common musk turtle does not have state, federal, or heritage ranking, but is considered threatened in Ontario. Water pollution, raccoon predations, and incidental mortality from fishing lines and traps are all threats to this species. Although they move less than <1 km in short bursts, in highly fragmented areas, high rates of road mortality can occur. They are also sensitive to land conversion and activity shifts after drainage of an inhabited pond has been observed. As with other turtles, this species is long-lived and can not endure chronic rates of mortality.

Pertinent Reference:
Ernst, C. H. 1986. Ecology of the turtle, Sternotherus odoratus, in southeastern Pennsylvania. Journal of Herpetology 20(3): 341-352.

Account Author: Kimberly Andrews, University of Georgia – edited by J.D. Willson