Common Snapping Turtles under Threat

“Snapping turtles, embodiment of turtles who shared the earth with the dinosaurs for a time and are now obliged to share it with the human species, might well report that the former companions were far less stressful.”

– D.M. Carroll – The Year of the Turtle: A natural history


DSC_6200 Jambalaya

There was good news for fresh water turtles from Canada in early 2017: Ontario banned the hunt of common snapping turtles.

In Canada, the common snapping turtle is the largest of all freshwater and terrestrial turtles. Snapping turtles are listed as a “species of special concern” in Ontario and have been on the province’s watch list since 2009. The snapping turtle is a long-lived species that takes many years to become sexually mature and reproduces slowly. They depend on high adult survival rates and snapping turtle populations will decline with even minor increases in adult deaths.

They are facing numerous threats. Habitat loss and hunting, being important ones, but the reptile’s greatest threat in Canada are drivers, with hundreds of turtles dying as road-kill each summer when adult females start looking for egg-laying sites. The females will often travel along roads and may nest on the shoulders, because they like sunny areas with gravelly soil and sand for making nests.

Still, it was the only turtle that could legally be hunted in Ontario. The province had allowed snapping turtle hunting all year in some areas, and between July 15 and September 15 in others. Hunters had a two-per-day bag limit.

The hunt had already declined in popularity to only a handful of cases each year, so it was a fairly easy decision for the government to end it.

The Ministry of Natural Resources and Forestry amended its regulations after months of public consultation, introducing an all out ban on the snapping turtle hunt starting April 1, 2017.

One group that opposed the ban was the Ontario Federation of Anglers and Hunters … of course.

The decision should have been a no-brainer: common snapping turtles face a number of threats so eliminating this one – deliberate killing – might just slow their decline.

DSC_5586 Jambalaya

There are two subspecies of snapping turtle (Chelydra serpentine) recognized in North America that are primarily distinguished by range: C. s. serpentina goes by the name of common snapping turtle, is the largest subspecies and lives primarily in the United States and Canada east of the Rockies. Its range extends from southern Alberta eastward across southern Canada to Nova Scotia, and south across the US, except for the southern portion of Texas and Florida. In that region the second subspecies, C. s. osceola, the Florida snapping turtle, occupies the Gulf coast and the Florida peninsula.

There are moderate mtDNA differences between individuals in North America and those in Central and South America and the latter two are in general considered separate species, Chelydra rossignonii and Chelydra acutirostris respectively.

Snapping turtles have long tails and necks, both about as long as the carapace. The carapace shell, serrated at the back, is covered with bony plates and can be black or dark-brown to green or tan and sometimes it is covered in algae. They have a large head with a sharp, hooked upper jaw. This hard beak has a rough cutting edge that is used for tearing food.

The tail has saw-toothed keels on it and their neck and legs have characteristic tubercles. Neck, legs, and tail have a yellowish-white color with the head a bit darker.

Their plastron – the stomach plate – is small and leaves much of the extremities exposed. This gives them a much better mobility than most turtles. When they walk on land they can raise their body up from the ground and only their tail is dragging.

Because they cannot hide in their shells when confronted, snapping turtles had to evolve another defense strategy: to snap. Snapping is their defense mechanism and snapping turtles will bite if threatened, but only as a last resort. He or she will first try to scare off a threat by hissing.

A snapping turtle bite is not exceptionally powerful. According to a study in the Journal of Evolutionary Biology from 2002, a snapping turtle’s actual jaw strength registered between 208 and 226 Newton of force. By comparison, humans average a bite force of between 300 and 700 Newton when we bite with our molars.

When in the water and unprovoked, snappers are fairly docile.

Snapping turtles are found in almost every freshwater habitat, including ponds, lakes, creeks and rivers, preferably with muddy bottoms and vegetation. Snapping turtles, instead of swimming, crawl or bounce along over the bottom in shallow water. They only float as long as they hold sufficient air in their lungs. They prefer to be able to reach the surface with their head, only their eyes and nostrils exposed, while sitting on the bottom, half-buried in the mud. The position of their eyes allows them to see straight above their heads.

Snapping turtles are most active at night, but as ectotherms they do not generate their own body heat. They need to draw external warmth to increase their metabolic rate and energy assimilation so that they will have enough fat reserves for the winter. They rarely rest on land, but instead bask on the water’s surface or occasionally crawl out on logs.

Snapping turtles are omnivorous. In early spring, when aquatic vegetation in lakes and ponds is still limited, they may eat primarily animal matter, laying in wait to ambush their prey of insects, crustaceans, clams, snails, earthworms, leeches, tubificid worms, freshwater sponges, fish (adults, fry and eggs), frogs and toads, salamanders, snakes, small turtles, birds, small mammals and carrion, however, when aquatic vegetation becomes abundant, they become more herbivorous, eating plant material including various algae.

Snapping turtles have a reputation – especially among hunters and fishermen looking to vilify the animal to justify killing ‘it’ – for decimating game fish and waterfowl populations, but scientific research indicates that this is not the case. Snappers, on the contrary, play an important role in maintaining healthy fish populations. The same holds in regard to waterfowl: snapping turtles and waterfowl have coexisted – in some cases for millions of years – long before some ape raised itself on its two hind legs – without exterminating them. In fact snappers probably play an important role as apex predator in the prevention of the spread of diseases from sick ducklings.

Carrion may compromise as much as 20% of snapper diet.

Males and females look very similar, although females have their cloacal opening – the combined opening for excretion and reproduction – much further forward.

They reach sexual maturity at approximately 8 inches (20 cm) in carapace length. Sexual maturity has more to do with size than age. The cooler, short-activity season in more northern areas results in slower growth rates and a prolonged time to reach sexual maturity. Females are sexually mature after about 8 years in Iowa, 10 to 20 years in Ontario – later in the north than south – and 11 to 16 years in southeastern Michigan.

Full-grown individuals can be between 8 and 18 inches in carapace length and weigh from 8 to 35 pounds. Since growth continues throughout life, very old individuals can grow very large and heavy.

Most snapping turtles stay primarily within the same marsh or in one general area from year to year. Large males have fixed home ranges, to which they show high fidelity, staying in the same spot for many years. They will even return over several miles if relocated. They dominate the most desirable locations through which females migrate on their way to the nesting sites and smaller individuals will avoid these ‘territories’.

When whole ponds dry up the inhabitants will move over land to the next water source. Snapping turtles require permanent bodies of water, but can survive without for at least 2 weeks. This allows them to make extensive migrations over land. Females are generally more mobile than males and may need to travel some distance outside of the aquatic foraging home range to find a suitable nest site. They represent the dispersal stage for snapping turtles and since they can retain sperm in their bodies for many years, they do not need to find mates every year to reproduce.

Snapping turtles usually enter hibernation by late October and emerge sometime between March and May, depending on latitude and temperature. They burrow into the mud at the bottom of ponds or lakes, settle beneath logs, or retreat into muskrat burrows, often in groups. They need places that do not freeze to the bottom.

During hibernation their body temperature is reduced to about 34°F/1°C. If the temperature drops further the turtles can freeze to death or be killed by the forming ice. During this time they hardly move.

Hibernating snapping turtles don’t need to breathe. While they can get oxygen by pushing their head out of the mud and allowing gas exchange to take place through the membranes of their mouth and throat – known as extrapulmonary respiration – they can also burn sugars and fats without the use of oxygen – an anaerobic way.

Snapping turtles communicate to potential mates with leg movements while the turtles face each other. Breeding season lasts from April to November, but the female’s option of sperm storage allows individuals to mate at any time of the year independent of female ovulation, and it also allows females to lay eggs every season without needing to mate.

In the mating process, the male positions himself on top of the female’s shell by grasping the shell with his claws. He then curves his tail until their cloacae touch and fertilization takes place. After the eggs have developed sufficiently in the female – in May or June – she excavates a shallow bowl-shaped nest with her powerful hind legs – normally in sandy soil, in a well-drained, sunny location – and lays, over a period of several hours, 20 to 40 creamy white, ping-pong ball-sized eggs. A clutch can, however, be as large as 100 eggs.

Hatching generally takes approximately 80 to 90 days, but can vary between 9 to 18 weeks, depending on temperature and other environmental conditions. Eggs maintained at 68°F produce only females, at 70-72°F they produce both male and female turtles, and those incubated at 73-75°F produce only males; therefore climate change could represent an important ‘new’ threat to turtle populations.

Hatchlings normally emerge from their leathery egg in August through October by using a small egg tooth to break open the shell, but northern snapping turtles sometimes overwinter in their egg stage. After hatching, the young dig their way out of the nest and instinctively head to water.

Snapping turtle ‘parents’ do not provide care for their babies.

While adult snappers have few enemies but man, their eggs and hatchlings might be eaten by other large turtles, herons, crows, raccoons, skunks, foxes, bullfrogs, water snakes and large predatory fish. Once snapping turtles become larger, there are few animals that prey on them. Snapping turtles can be aggressive and will fight back ferociously when attacked.

In the wild snapping turtles are estimated to live on average up to 30 years. In captivity they can live much longer.

DSC_5583 Jambalaya

While the hunt is banned in Ontario, the killing of wild common snapping turtles continues unabated in redneck-hillbilly areas in the USA and in this country hunting is their biggest threat.

Usually it is permitted under some kind of regulation – size and/or bag limits, closed seasons, area restrictions, gear restrictions, restrictions on commercial use, etc.

In New York State, common snapping turtle and diamondback terrapin can be caught. For snapping turtles a hunting license is required and the only legal implement for taking snapping turtles is a firearm, bow or crossbow. Open season for snapping turtles is July 15 through September 30 statewide. Hunting hours are any time of the day or night. The snapping turtle’s carapace must measure 12 inches or longer in length. The bag limit for snapping turtles is 5 per day or 30 per season.

In Missouri, the daily limit is 5 and the max possession limit is 10. You can take snapping turtles by hand, hand net, bow, crossbow, trotline, throw line, limb line, bank line, jug line, snagging, snaring, grabbing and pole and line, but you can’t shoot turtles with firearms.

In Michigan, from July 15 to September 15, you can catch snapping turtles with a carapace length of 13 inches and over, with 2 as a daily limit (including caught softshell turtles) and have 4 max total in possession, 2 of each species.

In Indiana, eastern snapping turtles, smooth softshell turtles and spiny softshell turtles can be taken between July 1 and March 31 of the following year and must have a carapace length of at least 12 inches. There is a daily limit of 4, while you can have 8 turtles in your possession at any time.

In Connecticut the season lasts from July 15 to September 30 with a bag Limit of 5 daily, possession 10, season 10. The size limit is a minimum of 13 inches carapace length. The legal catch methods are hand capture, dip net, turtle hook, floating or non-floating turtle trap and hook and line. Hook and line requires a fishing license. Using traps requires a free Snapping Turtle Trapping Endorsement.

In Ohio, turtle season was open from July 1 to December 31 in 2017. Only snapping and softshell turtles may be legally taken. They both must have a straight-line carapace length of 11 inches or greater to be taken, and there is no daily limit on the number that may be taken. A turtle trap with mesh less than 4 inches square must have an opening at least 6 inches in diameter leading from it. Wings and leads are unlawful. The trap must be marked with the name and address of the owner or user or customer identification number. All traps must be checked once every 24 hours.

In 2016, Iowa set new rules that would permit commercial hunting of common snapping turtles from July 16 to May 14 for the 60 or so Iowans with a commercial turtle harvest license. Recreational hunting is still permitted year-round, with daily catch limits of 4 common snapping turtles, one spiny softshell or smooth softshell turtle and one painted turtle. The rules set commercial possession limits of 20 common snapping turtles, five spiny softshell or smooth softshell turtles and five painted turtles.

Alabama, Maryland and Texas are a few other states where common snapping turtles are still hunted.

Snapping turtle shells were used in many ceremonies among Native Americans. The shells were dried and mounted on handles with corn kernels inside for use as rattles.

Common snapping turtles were eaten throughout their range. If captured alive, a turtle is killed by shooting it in the head, smashing in the head or cutting off the head. The animal is then bled from the neck. Next, the junction between upper and lower shell is severed, the carapace cut free, detaching the ribs. The legs are then skinned and the meat peeled out of the shell. The meat is soaked in cold water with added baking soda to firm it and draw out the blood. The bad-tasting yellow fat is removed. The turtle meat is put in a pot, covered and left to simmer for one and a half hour until the meat is tender and can be deboned. You can then add vegetables and spices to taste and let it simmer a while more. The meat is both light and dark in color and the killers will tell you that it has the combined flavors of pork, beef, fish and chicken. The meat can also be seasoned, breaded, seared and then oven-baked for at least three hours at 300 degrees. Leftovers end up in turtle soup.

In some restaurants turtle is on the menu only during Lent, a tradition as ridiculous and destructive as Chinese folk medicine. Because snapping turtles are cold-blooded, the meat is considered an acceptable alternative to fish. It has become a specialty menu item available only through commercial trappers, who deliver the product cut and frozen. The demand has dropped and it’s mostly an older, nostalgic generation ordering turtle. With the drop in demand and a drop in availability the price has increased from about 4 to 5 dollar a pound two decades ago to 12 to 14 dollar a pound today. This hopefully means turtle will disappear from the menu altogether.

Eating snapping turtles might not be a great idea anyway. Snapping turtles are one of the few species that survive in significantly polluted habitats, like urban wetlands and even sewer systems. Snapping turtles are long-lived and likely to bio-accumulate large levels of toxins – such as mercury, PCBs and pesticides – within their body tissues from prey and burrowing in contaminated sediment. They might pose a health risk and, as top aquatic predators, serve as environmental indicators.

DSC_5582 Jambalaya

In 1994, Congdon et al. still found that “[c]arefully managed sport harvests of some populations may be sustainable”, but that “commercial harvests will certainly cause substantial population declines”. In 1988, a US Forest Service Report on ‘Developing Management Guidelines for Snapping Turtles’, had already reported that the “northern population [of snapping turtles] cannot sustain even minimal exploitation by humans”.

A study by Haxton, published in 2000, concluded that “[n]esting females are especially vulnerable to overexploitation. Snapping turtles are vulnerable to high mortality on roads during the nesting season; this mortality could have negative impacts on the sustainability of local populations.”

The 2014 study ‘Modeling the Effects of Commercial Harvest on Population Growth of River Turtles’, said: “Commercial turtle harvest is considered one of the major contributing factors to declines in turtle populations. […] For both snapping turtles and softshells, harvest was sustainable when demographic rates were at the maximum values, which are highly improbable to occur frequently. […] In both species, elasticity analyses demonstrated that adults, which are the most vulnerable to commercial harvest, were the most important segment of the population demographically. These results corroborate the findings of other studies which indicate that even low annual harvest rates may have detrimental effects on the long-term sustainability of turtle populations at localized scales.”

DSC_5576 Gumbo

Canada’s ‘Species at Risk Public Registry’ points to a relatively new threat for common snapping turtles: “A new, rapidly increasing and far more serious threat is the illegal wildlife trade. There is a highly organized trade in turtles for food, medicine, pets and trinkets. Systematic trapping of all turtle species, including Snapping Turtles, is increasing to meet overseas demand, particularly from China.”

“Snapping turtles (Chelydra serpentina) are being harvested in unprecedented numbers in the United States to meet the needs of this international market,” is the conclusion of a 2017 study published in the Journal for Nature Conservation.

China’s massive hunger for turtle meat, shells and eggs has combined with dramatic declines in Asian turtle populations to put increasing pressure on North America’s freshwater turtles.

Commercial trappers in Virginia took more than 7900 snapping turtles in 2013. In 2015, the 101 commercial harvesters in Iowa caught 10,210 turtles with a wholesale value of $53,845.

Export to East Asia increased substantially in recent years, from about 10,000 animals declared as exported from the USA in 1999 to over 300,000 annually in recent years (LEMIS database – total recorded export numbers: 1999 10,053; 2000 18,486; 2001 38,911; 2002 63,644; 2003 129,683; 2004 141,544; 2005 316,500; 2006 377,408; 2007 316,093; 2008 558,491; available data do not allow differentiation of farmed vs. wild-collected trade volumes).

In February 2017, the Hartford Courant ran the headline: “Experts Fear Connecticut’s Snapping Turtles At Risk From Commercial Hunting”.

They reported that most of the Connecticut catch was sent to China and other Asian markets.

Until three years ago, the state didn’t even regulate snapping turtle hunting. A 30-turtle-per-year limit was placed on licensed trappers in 2013, and in 2016 the annual limit was reduced to 10 turtles because of worries about the snapper population. Only turtles with a carapace length of at least 13 inches are allowed to be trapped.

Connecticut still has no requirements for trappers to report how many snappers are being taken and cases of unlicensed trapping have been reported. According to state records, 588 turtle harvesting licenses were issued in 2016.

Jenny Dickson, a supervising biologist with Connecticut’s wildlife division, said: “We know their population has been declining, not just here in Connecticut but throughout the snapping turtle’s range.”

In Ohio traders can still legally collect unlimited numbers of common snapping and softshell turtles to process and sell domestically or export for Asian food and medicinal markets, but other states have recognized the havoc being perpetrated.

In 2009 Florida banned almost all commercial collection of freshwater turtles from public and private waters.

In 2012, Georgia approved state rules regulating the commercial collection of turtles, and Alabama completely banned commercial collection.

October 2016, the Missouri Department of Conservation announced that it will consider ending unlimited commercial collection of the state’s wild freshwater turtles.

New York, Massachusetts, Maine, Kentucky, Michigan, Indiana and West Virginia prohibit all commercial collection of turtles and Pennsylvania enforces strict bag limits.

New commercial regulations in Iowa limit the season from July 16 to May 14 for the 60 or so Iowans that commercially ‘harvest’ turtles and daily catch limits came into effect on March 22, 2017.

These new legislations do put extra pressure on the turtle populations in laxer states as trappers move their operations there.

DSC_5575 Gumbo

Adult turtles are also taken from the wild to breed hatchlings for the international pet trade. On websites such as baby common snapping turtles go for US$20-30, juveniles for US$40-60 and large adults cost more than US$250. And, yes, they ship live turtles by mail: “In the rare event that an animal perishes, before arriving at their destination, we will issue a store credit for the cost of the animal, provided that certain criteria are met.”

The common snapping turtle is not an ideal pet. It will not be very active during the day. Its neck is very flexible, and this turtle can bite its handler even if picked up by the sides of its shell.

Common snapping turtles are an apex predator and removing them out of freshwater ecosystems will have environmental consequences.

The IUCN and the national red lists for endangered species seem to lag behind. They generally consider snapping turtles as not significantly threatened overall and they are listed as ‘least concern’. The science, however, is clear: turtle populations cannot sustain even small increases in adult mortality.

Fresh water turtles are facing boat mortality, fishing by-catch, mortality from dredging and construction, invasive species, persecution, illegal collection, exposure to toxic contaminants, etc.

Effective November 21, 2016, the United States listed the common snapping turtle (Chelydra serpentina), Florida softshell turtle (Apolone ferox), smooth softshell turtle (Apalone mutica), and spiny softshell turtle (Apalone spinifera) in Appendix III of CITES. In June 2006, the alligator snapping turtle (Macroclemys temminckii) and all species of map turtle (Graptemys spp.) had already been listed in Appendix III.

Including the turtles listed by the United States, a total of 26 freshwater turtle species are listed in Appendix III.

If you live in or travel through common snapping turtle habitat – rural areas with wetlands, east of the Rockies – in spring and summer, drive careful and slowly; watch the road for crossing turtles.

If you need to pick up a snapper – which is not recommended – to move her (as explained above it is in general the female that wanders) off the road, you can use your car mat, a shovel or a blanket. You can coax her along from the back or scoop her up with a shovel to get her across. Whatever you do, push her in the direction she is already headed, because the turtle is going to go in that direction anyway.

If you need to pick her up by hand, don’t grab her from the front or the sides; you will get bitten! pick her up from the back of the shell on either side of the tail and drag her in the direction she’s already headed. Never pick a snapping turtle up by the tail, as this can damage the animal’s vertebral column and tail; only hunters are that cruel!

In the accompanying photos you can see Gumbo and Jumbalaya who live out their lives at Wildlife Waystation. Female Jumbalaya arrived in 2000 at 19 years of age and male Gumbo has been living here since 1994, when he was 22.



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s