Seven of Ontario’s eight native freshwater turtle species are currently at risk. WPC has been working on the problem since 2004, when we launched a research project into nesting success in two of Ontario’s largest, most important turtle nesting areas. This research showed that, even though the nesting sites were in prime, protected habitat inside national and provincial parks, virtually 100% of all turtle nests were being destroyed within 48 hours of being laid!
The culprit? Natural predators such as raccoons and skunks, whose populations have been given a boost beyond natural levels due to inadvertent subsidization by human campers and cottagers. The implications are staggering but help explain why many of Ontario’s turtle populations, in both urban and rural areas, consist primarily of older adults. Anywhere there are people, there are subsidized populations of raccoons and other omnivorous nest predators. There aren’t any young turtles because the eggs are not even making it to the hatchling stage.
Since 2005, WPC’s freshwater turtle program has supported research and conservation strategies that reduce nest failures and protect nests and eggs from mammalian predation. Starting in 2005, MSc. and then PhD candidate Ryan Bolton used motion-activated cameras at night to identify raccoons and skunks as the main predators, followed by opossums and coyotes. Ryan’s project trialed a variety of mitigation techniques over the years including: in situ protection using wire cages placed directly over nests, relocation of nests to large-scale predator exclosures, moving nests to other locations along beaches used for breeding, and artificial incubation in a lab setting. By 2010 Ryan found that each method has its own inherent pros and cons, but all methods ensure that a large number of nests hatch, and Ryan’s work saved over 4,000 eggs from predation.
In 2011, project leader Christina Davy and her team were able to save and release over 800 hatchlings, bringing WPC’s all-time total to roughly 5,000 Blanding’s, northern map, snapping, spiny softshell, and spotted turtle hatchlings saved. These young turtles can now begin the arduous, multi-year journey to maturity. Christina’s project also includes mark-recapture work which allows for direct monitoring of the these threatened populations. Mark-recapture surveys allow changes in population size over time to be detected so that population declines can be investigated and mitigated. As part of her PhD work, Christina is looking into the conservation genetics of spotted turtles and developing microsatellite markers for spiny-softshell and snapping turtles which will be used to assess the genetic diversity and relatedness of at-risk populations.
Learn more about the freshwater turtle species WPC is helping to save.