HELP SAVE MAINE'S THREATENED SNAPPING TURTLES

Each year in Maine, thousands of Snapping turtles are killed on roads. This alone is sufficient to seriously damage long term prospects for survival of these ancient populations. In addition to this drain upon numbers, however, Maine currently permits the large-scale trapping and killing of Snapping turtles, thereby GUARANTEEING that the species will continue to decline towards ultimate EXTINCTION in the State.

LATEST UPDATE - WE WON THE PUBLIC HEARING!

Contrary to much ill-informed popular opinion, Snapping turtles are fascinating, fantastic turtles that actively contribute to a well balanced ecosystem. They are not 'pests' and they are not a sustainable 'game species'.

In addition to the issue of conservation, it is extremely difficult to kill Snapping turtles humanely. This is therefore a practice that is particularly cruel and gruesome as this eye-witness account relates:

"A long time ago, at summer camp, our nature instructor found a snapper that had been hit on the road.  It was injured and he decided to dissect it for a class.  A large stick was presented to the snapper and it was grabbed by the jaws, the neck was stretched and the head then removed by an axe.  What one would normally consider a quick and painless death.  However, an hour and a half later, after the class on the internal organs, the meat was removed, etc, we re-examined the head.  It was still reactive, the eyes blinked and focused on objects and tracked movement.  The jaws still closed with considerable force on objects inserted into the mouth.  The brain was still 'living'.  I would not wish this type of demise on anything.  I do not believe it is possible to 'humanely' kill a snapper, at least not with anything short of chemical agents.

Glen M. Jacobsen"

The Tortoise Trust calls for this unsustainable and cruel trade to end immediately, and for Snapping turtles to be given the protection they deserve. They are an integral and irreplaceable component of Maine's natural history heritage. They need protection now - or they will be lost forever.

 1. Email the Director of Wildlife Division, Mark Stadler, to express your concerns about this situation and to politely demand that Snapping turtles receive adequate protection - a complete ban on collecting without delay:

2. Contact L.L. Bean and suggest that they support this effort to save their home state's most ancient resident..... if not, maybe you should think about shopping with a more eco-friendly company instead. You can send customer comments by clicking this link:

ASK L.L. BEAN TO HELP

3. Call the Maine Office of Tourism 1-888-624-6345 (toll-free in US) or email them on mtainfo@mainetourism.com to complain at the cruel and unsustainable nature of this 'harvest'. You can also let the Maine Innkeeper's Association (info@maineinns.com) and the Maine Campground Owner's Association (info@campmaine.com) know why you will not be visiting Maine until this situation is resolved as well....

PLEASE ACT NOW!

DETAILED PROPOSALS

Populations of the common snapping turtle Chelydra serpentina serpentina on the northern edge of the species’ range are generally barely sustainable in the absence of human disturbance. Snapping turtles are a k-selected species with a life history strategy of late maturity and low reproductive output over a long range of years with virtually no natural adult mortality.¹ Age of maturity is approximately 19 years, and survivorship from egg to adult has been shown to be only 1/1445 in the Algonquin study population.^{2, 3} The most recent estimates are even as low as 1/7000.⁴ With an average clutch size of 30 eggs per year, this requires that a female turtle has a reproductive lifespan of at least 100 years to reproduce itself and its mate. Theoretical longevity for this species is estimated to be 170 years in northern populations.¹ Because clutch size increases proportionally to body size, the largest females are most important for the population.¹

Preliminary data from the Washington County Snapping Turtle Study (WCSTS) has shown that the age of maturity in eastern Maine is similar to or even slightly higher than that of the Algonquin study population (mean 20.89 +/- 4.77, range 14-34), which clearly identifies the eastern populations of Maine’s snapping turtles as having the life history parameters of northern populations.⁵

Maine’s snapping turtles have been severely reduced in numbers through both trapping and road mortality. Concentrated nesting on roads has also dramatically increased mammalian egg predation (up to 94% of nests are destroyed).¹ Road mortality affects mostly nesting females and hatchlings. Preliminary data from the WCSTS indicates that only 8-12% of females are older than 40 years, and that only 4-8% of females reach 30 cm carapace length (which should be reached between 35 and 50 years of age).⁵ In a reasonably undisturbed population at least 20% of females should have that size.⁴ This indicates that road mortality is significantly reducing female survivorship, effectively resulting in a reproductive lifespan of less than 20 years, only 1/5 of the time necessary for population stability.

It has been shown that even in a more southern population of snapping turtles increased adult mortality of only 10% will halve the population in only 15 years.⁶ Consequently northern populations have to be protected completely to continue to exist. ^2,3 Northern population in fact do not appear to be productive enough at this time to maintain their own numbers even in the absence of trapping, which means that a further population decline is occurring and even under the most ideal circumstances a population increase is impossible.^{2, 4}

From those facts it is clear that the only way to save Maine’s snapping turtles is a complete and immediate end to all harvesting. Maintaining a sustainable snapping turtle population is important not only for biodiversity reasons but also because it appears to enhance game fish populations due to the snapping turtle’s food preference for non-game species (besides aquatic vegetation which makes up the bulk of their diet.). ²

Since it appears to be politically impossible to close snapping turtle harvesting completely at this point, a phase-out of snapping turtle harvesting is recommended. It is essential that during this phase-out any additional female mortality, especially of large females, is strictly avoided, while steps are simultaneously taken to reduce non-harvest related female mortality (road kill) and to increase nest survivorship.

It is however important to consider that while the number of females represents the reproductive potential of the population, a 50:50 sex ratio has evolved in this species (since snapping turtles have temperature dependent sex determination this is not an artifact of genetics).⁷ There are strong indications that the insulating layer which males form over the females during hibernation may be one of the ways in which males enhance female survival. A large male population is also important for genetic variability since turtles produce offspring from several mates at each nesting.⁸ Care must be taken not to remove so many males from the population during the phasing out, that the sex ratio, which is currently skewed towards males, drops below 50%.

Recommended steps in order of priority:

1. Close the wildlife management districts within the snapping turtle’s range east of the Penobscot River to snapping turtle trapping immediately, especially the districts encompassing all of the watersheds of the downeast rivers (WMD 27-29, 18 and 19 and preferably 11). Since snapping turtles move up and down along their watershed the complete watershed has to be included. [Turtle populations further north and inland (WMD 5, 6, and 10) and towards the mountains (WMD 9 and 12 to 14 and everything north from there) are of unknown extent and probably naturally too marginal to play a major role, but should be included in the closure eventually. This area should however be unappealing to harvesters anyways because of the naturally low turtle densities.] Due to lower road densities and historically lower harvesting levels, most large females, which are essential and irreplaceable for a stabilization of the population (since they lay the most eggs), remain in the downeast region. If this area is not closed they could be legally taken regardless of how high the size limit is since a 100 to 170 year old female would even be larger than 14 inches. A single year of trapping could destroy every chance for the stabilization of the eastern population. Because of the climatic conditions nesting in this area of the state extends also later into the summer than in the south and hibernation starts earlier, making it impossible to define a season which would assure that neither females are preferentially trapped nor hibernacula disturbed. Stabilization of the population might also still be possible in this area due to the lower road mortality and the presence of at least a few large females, while snapping turtle populations in the area southwest of the Penobscot River (WMD 20 to 26, and 15 to 17) can likely not be stabilized without other measures which would dramatically decrease road mortality (signage, extensive fencing). Once those measures are taken stabilization might hopefully be possible due to the slightly better growth rates caused by the more favorable climatic conditions. At this point it is highly unlikely that any large females remain in that area. Despite the claim of turtle trappers that males are preferentially trapped, those large females which have not been killed on the roads have likely been removed by harvesters. A single year of harvesting could do irreparable damage to the remaining large females in the eastern region, while if a sufficiently high size limit is established, several more years of harvesting would do little damage to the female population in the southwestern region, where female size is likely to be much lower. Because of the increased female mortality the sex ratio must be skewed towards males, and since population sustainability is based on the female population as long as the male to female sex ratio does not fall below 50:50, the southwestern population should not suffer increased damage if a limited number of males are removed during the phasing out. 

Since most turtle trapping is taking place in southern/western Maine at this point anyways, there should not be too much opposition against the closure of the downeast region. It can also be made more appealing by explaining (rightly) that regulations can be a lot looser if eastern Maine is not included in the harvest.

A final consideration here is the Atlantic Salmon issue since snapping turtles play potentially a role in the success of salmon by reducing non-game fish species which impact salmon through disturbance as well as competition.

2. Issue no new permits. With a seasonal limit of 100 turtles commercial harvesters will immediately attempt to make up for their losses by contracting out the trapping. Snapping turtle trapping is currently low because most people are unaware that it is profitable. If the commercial harvesters hire contract trappers, this will guarantee a profit to those individuals, creating a new lobby of turtle trappers which would maintain the harvest at current levels and which would create a vocal obstacle to a complete closure. Also because of the protection of the Alligator Snapping Turtle in the USA and the protection of Common Snapping Turtle in Ontario, US and Canadian turtle trappers are seeking to expand their activities into Maine. Because of the extinction of the Asian turtles, Chinese turtle trappers (very large-scale operations) are also moving into the US (according to Traffic USA) and will likely attempt to move into Maine within the next years. They have already become a problem in Canada.⁴

Politically turtle trappers should view a proposal that they can renew their permits annually but that no other competition would be allowed definitely as favorable since it protects their interests.

3. Set a seasonal possession limit of 100 turtles (1000 turtles total with 10 permits). Set a goal of reducing this amount by 100 turtles per year. I would hope that this would happen naturally as the trappers loose interest or age, resulting in a reduction of the permits to 9, 8, etc. without any further regulatory action. If this does not occur the seasonal limit could be reduced by 10 turtles per year, or alternatively halved after 5 and 7 years and phased out after 10. After this time the 50:50 sex ratio might be reestablished in southern Maine and a further drop in the male population would be detrimental.

4. Set a lower size limit, which biases the harvest heavily towards males. 12 inches would be the absolute minimum but would be problematic since exact measurements and enforcement would be required to protect females in the 11 to 12 inch size category (which should exist even in the southwestern part of the State). Measurements have to be taken with tree calipers along the centerline of the carapace, which requires considerable experience for accuracy. A size limit of 14 inches would protect the great majority of females in the southern populations for at least a decade even if efforts are being made to reduce road mortality. Politically I don’t imagine that this would be any less popular than a 12 inch limit since there should still be enough large males available in the southern part of the State (they are not subject to road mortality) and since trappers would prefer bigger turtles anyways.

5. Set a season which avoids biasing the harvest towards females by starting as late as possible (July 15 at the earliest) and ends well before movement into hibernacula to avoid disturbance and consequent winter death of females and sub-legal males (September 15 at the latest).

6. Require harvesting methods which ensure the life release of sub-legal animals.

Links on Snapping Turtle Biology & Exploitation

Detailed Report on the Biology and Conservation of Snapping Turtles in Maine

The Law in Maine

References:

1. Obbard ME 1983 Population ecology of the common snapping turtle, Chelydra serpentina, in north-central Ontario. Ph.D. dissertation, University of Guelph, Guelph, Ont.182 pp. 

2. Brooks RJ, Galbraith DA, Nancekivell EG, Bishop CA 1988 Developing Management Guidelines for Snapping Turtles. In:  Szaro RC, Severson KE, Patton DR (eds.) Management of Amphibians, Reptiles, and Small Mammals in North America. Proceedings of the Symposium, July 19-21, 1988, Flagstaff, Arizona. USDA Forest Service General Technical Report RM-166, pp174-179   

3. Brooks RJ, Brown GP, Galbraith DA 1991 Effects of a sudden increase in natural mortality of adults on a population of the common snapping turtle (Chelydra serpentina). Can. J. Zool. 69:1214-1320

4. Brooks RJ personal communication.  

5. Kynast SSN Washington County Snapping Turtle Study (WCSTS) unpublished data.

6.  Congdon JD, Dunham AE, van Loben Sels RC 1994 Demographics of Common Snapping Turtles (Chelydra serpentina): Implications for conservation and management of long-lived organisms. Amer. Zool. 34:397-408   

7. Yntema CL 1979 Temperature levels and periods of sex determination during incubation of eggs of Chelydra serpentina. J. Morphol. 159:17-28 

8. Galbraith DA 1991 Studies of mating systems in Wood Turtles (Clemmys insculpta) and Snapping Turtles (Chelydra serpentina) using DNA fingerprinting. Ph.D. dissertation, Queen’s University, Kingston, Ontario. 182 p.

Technical text and photos by Susanne Kynast

Campaign text by The Tortoise Trust