Blanding's turtle COSEWIC assessment and status report: chapter 10

Limiting Factors and Threats

Because individual Blanding’s Turtles travel large distances over land, they are particularly susceptible to being struck and killed crossing roadways (Ashley and Robinson 1996; Harding 1997), especially because this species tends to travel along roadways (Ron Brooks, pers. comm.). Instances of dead on road Blanding’s Turtles have been reported in Scarborough, Point Pelee N.P., Algonquin P.P., Sudbury, St. Clair N.W.A., Halton, Long Point P.P., Parry Sound, Renfrew, Merrickville, Rondeau P.P., Kempville, and Bancroft (Ashley and Robinson 1996; Bob Johnson, Constance Browne, Norm Quinn, Mike Hall, John Haggeman, Kim Barrett, Glenda Clayton, Lauren Trute, David and Carolyn Seburn, Sandy Dobbyn, pers. comm. May 25, 2004; Chris Burns, pers. comm. June 4, 2004; Angie Horner, pers. comm. June 6, 2004; Ontario Herpetofaunal Summary 2004). Blanding’s Turtles have also been reported dead on roadway in Québec (Desroches and Picard 2005), in the regions of Outaouais, and west of Gatineau Park (Jean-François Desroches , pers. comm. May 25, 2004; Daniel St-Hilaire, pers. comm. June 1, 2004; Joël Bonin, pers. comm. June 9, 2004 ). Of the 1908 records for Blanding’s Turtles in the OHS database, 9.8% were reported dead on roadway (DOR) (Oldham 1998). Again, given the long-lived life history of this species, losses of adult females to vehicles have a long-term impact on the population, and it is difficult for the population to recover from these losses (Congdon et al. 1993, Herman et al. 2003). This concern has been realized in the male-biased population in Big Creek N.W.A. (Saumure 1995, 1997; Gillingwater unpublished data).

The development of wetlands and the terrestrial ecosystems that surround them is a severe threat to the population of Blanding’s Turtles in Ontario/Québec. Not only must the waterways and the immediate surrounding areas be protected, but also nesting areas as far as 1620m from such waterways (Joyal et al. 2001).

The development of interest from the pet trade for Blanding’s Turtles presents a threat to survivorships of all ages. Captive-bred yearling Blanding’s Turtles are for sale online by the Amazon Reptile Center (2005). These animals are also available to Canadian residents (Amazon Reptile Center, pers. comm. Feb. 16, 2005). This relatively high price makes it very appealing for individuals to risk fines and imprisonment, for the potential financial windfall that the sale of a few individuals can bring. Individuals who collect species from the wild do not discriminate between age classes, and will remove whatever they can catch. Usually, adult females are removed from wild populations as they are easier to locate and catch, and will receive a higher price at sale, and may provide a clutch of eggs as well. Removal of individuals from the wild for the pet trade is a developing threat, but the severity of its impact is difficult to estimate at this time. However, a recent study on impact of collection of roadside nesting female snapping turtles suggests the impact can be very significant (Tucker and Lamer 2004).

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