Monday, November 9, 2009

Small and Smelly Wins the Race: Life as a Stinkpot

By Heather Lunn, Senior Interpreter
(Photo by Simon Lunn)

Murphys Point has five species of turtles that call the park home. The smallest of the five, and most elusive, is the stinkpot turtle (also known as musk turtle or Sternotherus odoratus). Unless you are in a canoe and looking very carefully at the muddy bottom or amongst the aquatic vegetation, you are very unlikely to ever see a stinkpot turtle. These turtles are mainly nocturnal and rarely come out of water to bask like other turtles. Basking is usually done while partially submerged in shallow water. The only time you may find a stinkpot on land is when females come out to lay eggs in the spring. Even then, however, female stinkpots tend to lay their 3 to 6 eggs close to the water’s edge in debris or in a shallowly excavated nest.

Stinkpots are aptly named because when agitated they do, in fact, stink. They have four glands underneath their shell that will emit a fluid that smells vaguely similar to the spray of a skunk. Comparable to a snapping turtle, stinkpots have a very small plastron and are not able to pull their legs or head inside their shell. Therefore they have developed their stinky defence to deter predators from eating them. Like a snapping turtle, these small turtles can stretch out their long necks and bite if not handled with care.

Although they are highly aquatic turtles, stinkpots are not very fast swimmers. Instead, they are often found walking along the muddy bottoms of lakes and marshes. One must look carefully when searching for this tiny turtle because when holding still they appear very similar to an algae covered rock. They are also often confused with young snapping turtles, but are distinguishable by their pointy snout and yellow lines running from the tip of their nose to behind their eye.

As an aquatic turtle, the stinkpot’s source of food lies mainly in the water. The stinkpot feeds on a range of invertebrates and other things, including leeches, aquatic insects, crustaceans, molluscs, small fish, tadpoles, aquatic plants, and even carrion if it is not overly decayed.

Stinkpots can live a long life of up to 50 years if they are in a productive environment. However, many stinkpot turtles are in trouble. Listed as a threatened species both provincially and federally, the main factors leading to their population decline are shoreline development and drainage of wetland habitats. Stinkpots use shoreline vegetation and adjacent aquatic plants for shelter, food, and nesting habitat. When plant life is removed, or the shoreline is “cleaned up,” there is less habitat to support stinkpot populations. If wetlands that contain stinkpot turtles are drained, the majority of the stinkpots will perish. This is because unlike other turtles, stinkpots lose the water in their body quickly if they are on dry land for too long. Therefore, if the wetland they live in is drained, they are not able to travel great distances over land to find a new one.

At Murphys Point it is our responsibility to protect our stinkpot turtles to ensure their place in the park’s fragile ecosystems. At home you too can help stinkpots by conserving wetlands on your property or maintaining natural shorelines. These secretive little turtles will thank you!

References
Harding, James H. (2006). Amphibians and Reptiles of the Great Lakes Region. The University of Michigan Press: United States of America.

MacCulloch, Ross D. (2002). The ROM Field Guide to Amphibians and Reptiles of Ontario. Royal Ontario Museum: Toronto.

Martin, A. Stinkpot Turtle. Retrieved September 13, 2009, from http://www.nipissing-naturalist.com/SAR/stinkpot.htm

Parks Canada. (2009). Stinkpot Turtle. Retrieved September 13, 2009, from http://www.pc.gc.ca/eng/nature/eep-sar/itm3/eep-sar3z.aspx