Most people, including anglers in Michigan, rarely see a snapping turtle in the wild. The most common time we see them is when we are driving in the early summer and we encounter an adult female moving to lay its eggs near the road in a sandy or fine gravel area. Retired Conservation Officer Mike Webster commented to me that he typically observed snapping turtles in the U.P. during nesting activity about the summer solstice each year. Of course, the turtles are very vulnerable at this time of year when attempting to lay their eggs.

The powerful looking mouth of a large snapping turtle. Copyright images by Joni Roberts.

Some people have a perception that snapping turtles are fierce animals. This perception likely comes from their primitive armored appearance and stories of them biting down hard on a stick when someone is harassing them during their attempt to lay eggs. I remember my first close encounter with a large snapping turtle, and it made a major impression on me as a rookie fish biologist with its formidable, sharp, hooked upper jaw, large claws and dinosaur-looking armored tail. I had to wrestle it out of our fyke (trap) net and release it unharmed back into the lake in the U.P.’s Hiawatha National Forest.

Snapping Turtle Biology

Typically, snapping turtles’ diet consists of a significant number of aquatic plants and opportunistically feeding on fish (dead or alive), insects, worms, amphibians, snakes, crayfish, baby ducks, small mammals and carrion.

Snapping turtles can grow relatively large in Michigan. In the wild, snapping turtles eventually grow to about 45 pounds, although reportedly, the largest documented wild-caught snapping turtle was from Texas at over 200 pounds.

Michigan research indicates it can take snapping turtle females between 11 to 16 years to mature. In addition, adult snappers do not always nest annually. Snapping turtle studies indicate they typically live 40 years in the wild, although reportedly, they can live 100 years. This is similar to lake sturgeon for life span. Typically, animals with long life spans cannot sustain high mortality rates and maintain their population. Snapping turtles’ egg nests are very vulnerable to a number of egg predators, most notably raccoons, skunks, etc. Raccoon populations are at an all-time high right now.

Juvenile snappers are also very vulnerable to predation, studies indicate 99.4% of snapping turtles die before reaching the average maturity age of 12 years. Research on snapping turtles also indicates that under natural conditions, conversely mortality of adult snapping turtles is relatively low. However, if mortality were high in adult snappers, their population would decline dramatically. There are a number of threats to adult snappers.

Greatest Threats

Tom Goniea, fisheries biologist for the Michigan DNR fisheries staff, said one major threat to the snapping turtle population is what he called “turtle mining” by commercial turtle trappers. Much of the threat of commercial turtle trapping is generated by the extremely high demand for live turtles in China’s animal trade markets. Goniea said live snapping turtles fetch a high price per pound, which means a typical adult snapper sells for an average price of $662 in Hong Kong, China (2016). Reportedly, in 2005, 275,896 live snapping turtles were exported from the U.S. to Asia. Goniea continued that 50% of turtle species being shipped to Asia markets are listed as endangered or critically endangered.

After a compelling scientific case was made by biologists from the DNR fisheries division, commercial turtle and amphibian trapping was made illegal in 2008.

Other Threats

Goniea mentioned a few other threats to snapping turtle survival as they do not have many natural predators. Vehicle strikes are one threat to adult snappers. Nesting habitat loss to human development can concentrate any area snapping turtle nesting grounds to a small suitable area, therefore making it more likely for nest predators like raccoons to be able to wipe out nests. An additional loss of adult snapping turtles would be to the legal “recreational” snapping turtle harvest. Of course, with their high potential value, illegal commercial poaching is always a threat.

Summary

Remember, snapping turtles in the water are considered docile unless aggressively provoked. On land, they are very vulnerable, and although they look ferocious, it is because they look so primitive, similarly the way a sturgeon does. Just like a sturgeon, snapping turtles have evolved to live a long time in the Michigan aquatic environment if we prevent illegal harvest and generally leave them alone.