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Quotes & Trivia
Come forth into the light of things, let nature be your teacher. ---Wordsworth
In all things of nature there is something of the marvelous. ---Aristotle
No man ever steps in the same river twice. ---Heraclitus
Nothing in biology makes sense except in light of evolution.
---Dobzhansky
To keep every cog and wheel is the first precaution of intelligent tinkering. ---Leopold
A bad day in the field is still better than a good day in the lab. ---Hecnar
Turtle Ecology and Conservation
In an evolutionary sense, turtles are a success story---their basic body plan has remained unchanged for over 200 million years. Although the Order: Testudines was formerly more diverse, there are presently about 280 extant species and many are of conservation concern. Ironically, the characteristics which made them successful, their protective shells and life histories, may now place them at increased risk of extinction. Life history characteristics such as long life spans, delayed maturity, and low recruitment make populations vulnerable to losses of even a small number of individuals. Because of their longevity, presence of a few turtles can give the impression that a population is healthy despite a lack of recruitment. Important threats to turtles include: habitat loss and degradation, road mortality, predation on nests and juveniles by subsidized mesopredators, and collection as pets.
Basking trap for freshwater turtles. Photo: C. Browne
We have been studying the structure of turtle populations and communities at Point Pelee National Park. Historically Point Pelee had the highest turtle diversity in Canada but evidence exists of population declines and species loss. We are using live trapping techniques and mark-recapture studies to determine the status of turtle populations. To date, we have documented shifts in age/size structure of turtles, changes in the abundance structure of the turtle community, and uncovered evidence suggesting that lack of recruitment is an important threat. Our documentation of high levels of raccoon predation and nest protection experiments led to the development of an ongoing nest protection program.
Baited hoop trap used to live-capture freshwater turtles Photo: S. Hecnar
We have also conducted experiments to test the efficacy of trapping techniques. The floating basking traps we constructed are more effective for capturing species such as map and painted turtles which frequently bask, while baited hoop traps are more effective for capturing more aquatic species such as snapping turtles. This work has been funded primarily by Parks Canada, with additional support from PREA and NSERC.
Use of screened nest boxes protects turtle eggs from raccoon predation
Photo: S.Hecnar
In terms of turtle diversity, Northwestern Ontario is not particularly rich---where only two species occur (painted, snapping). However, both of these species reach their northern limits of distribution in the region. Relatively little is known about northern peripheral turtle populations relative to those in more central and southern portions of their ranges. We have just begun to study the demographics and habitat/landscape relationships of western painted turtles on the edge of their range. We recently discovered painted turtles that have characteristics intermediate between western and midland subspecies in the Algoma District of Ontario. Our analyses suggest that this region functioned as a two-way post-Pleistocene corridor between Ontario and the Upper Peninsula of Michigan. This work is a spinoff of U.S. EPA/OMNR funded research and also supported through NSERC.