Pacific pond turtle (Clemmys marmorata) COSEWIC assessment and status report: chapter 4
Distribution
North American range
Historically, the Pacific pond turtle was distributed along the west coast of North America from southern British Columbia to the Baja Peninsula (Bury 1970a; Carr 1952; Figure 1). The majority of the turtle’s distribution is now restricted to coastal California and the Baja Peninsula, with small isolated inland populations in Washington, Oregon, along the Mojave River in California, and possibly Nevada, although the population is now thought to be extirpated (Ernst et al. 1994; Lovich and Meyer In Press; Figure 2). Clemmys marmorata remains have been found in Pleistocene era deposits, such as Lake Manix and the La Brea Tar Pits in California (Ernst et al. 1994).
Figure 1. Historic range of Clemmys marmorata in North America (after Carr 1952).
Figure 2. Current range of Clemmys marmorata in North America (by D. Holland, published in USACE website).
There are three validated records of the Pacific pond turtle in the Vancouver area of British Columbia from 1933, 1936 and 1959 (Bury 1970a; Cook 1984). Before 1950, there were also unverified sightings of this turtle on Vancouver Island (Bury 1970a). While there is some debate over the number and validity of the records of this turtle in Canada (Carr 1952; Ernst et al. 1994; Cook 1984), there is no biogeographic basis for this turtle’s range not to have extended into Canada (B. Bury pers. comm.). First, the climate in southwestern British Columbia is favourable for Clemmys marmorata, particularly areas having hot and dry summers and oak-woodland habitat. The Canadian populations may have been established when a warming period in the Pleistocene opened up a “banana belt” from the Puget Sound trough to the east side of Vancouver Island (B. Bury pers. comm.). Second, the Pacific pond turtle was common in the Puget Sound area (which extends almost to the Canadian border) even into the 1960s (B. Bury pers. comm.).
Page details
- Date modified: