scholarly journals Survival and Spatial Ecology of the Snapping Turtle, Chelydra serpentina, on the Upper Mississippi River

2009 ◽  
Vol 123 (4) ◽  
pp. 329 ◽  
Author(s):  
R. Neal Paisley ◽  
John F. Wetzel ◽  
John S. Nelson ◽  
Cindy Stetzer ◽  
Mark G. Hamernick ◽  
...  

We studied the survival and spatial ecology of adult Snapping Turtles (Chelydra serpentina) on Pool 8 of the Upper Mississippi River (UMR) during 1997-2001. We captured 597 Snapping Turtles 745 times (333 adult males; 238 adult females; and 26 juveniles) at two study sites; Goose Island, Wisconsin and Lawrence Lake, Minnesota. From this sample, we radio-marked 104 Snapping Turtles of legal harvest size 128 times. Annual survival ranged from 0.857 to 1.000 and averaged 0.944 with Goose Island and Lawrence Lake estimates pooled. Legal harvest was the most important cause of mortality and accounted for 57% of documented deaths. Annual home range size using the Poly-Buff (PB) method averaged 11.13 ha and ranged from 2.20 ha to 37.18 ha. Emergent and rooted-floating aquatic vegetation were used disproportionally more than their availability and 72% of all locations collected during the active period occurred within these habitat types. Overall, radio-marked Snapping Turtles selected hibernacula in the following habitat categories; marshes (38%), main/side channels (28%), backwater sloughs and small ponds (14%), spring areas (10%), small tributary streams (7%), and tertiary channels (3%). Developing conservative, consistent harvest regulations among the states that border the UMR should be a management priority.

2015 ◽  
Vol 93 (7) ◽  
pp. 509-514 ◽  
Author(s):  
Caleb T. Hasler ◽  
Kevin Robinson ◽  
Nick Stow ◽  
Shawn R. Taylor

Between 2010 and 2011, an arterial road was constructed within provincially significant wetlands in the South March Highlands (SMH) located in Ottawa, Ontario, Canada. The wetlands and adjacent upland areas were determined to be sensitive habitat for Blanding’s Turtles (Emydoidea blandingii (Holbrook, 1838)) during the approval and permitting process, and a population study was required as part of the road construction project. The study consisted of a 4-year mark–recapture program and a movement study of radio-tagged adult turtles. General findings included the identification of 27 adult males and 55 females and a population estimate of 93 adults (95% Cl: 86–118). A 1:2.32 male to female sex bias was also found. Mean home-range size was 19.06 ha and tagged turtles moved, on average, more per observation in 2013 (191.40 m compared with 89.75 and 123.04 m in 2011 and 2012, respectively). Previously reported differences in movement patterns between males, females, and gravid females were not observed. The SMH Blanding’s Turtle population should be closely monitored because urban development continues in the area, which may further reduce the population size. Understanding the biology of imperiled populations across species’ ranges is necessary to promote conservation and adaptive wildlife management.


2010 ◽  
Vol 104 (1-3) ◽  
pp. 309-324 ◽  
Author(s):  
Rebecca M. Kreiling ◽  
William B. Richardson ◽  
Jennifer C. Cavanaugh ◽  
Lynn A. Bartsch

1998 ◽  
Vol 201 (3) ◽  
pp. 439-449
Author(s):  
S O'Steen

Snapping turtles (Chelydra serpentina) demonstrate temperature-dependent sex determination (TSD): intermediate egg incubation temperatures (23-27 degreesC) produce males, while extreme temperatures produce females. Snapping turtles are also sexually dimorphic: adult males are typically larger than females. Previous researchers hypothesized that male-producing egg temperatures enhanced the growth rate of juvenile turtles, resulting in the adult dimorphism and potentially providing an adaptive benefit for TSD. In reptiles, the choice of ambient temperature can also influence growth. I measured the effect of egg incubation temperature on juvenile growth rate and water temperature choice of C. serpentina. Eggs were incubated in the laboratory at 21.5, 24.5, 27.5 or 30.5 degreesC to produce both sexes, all males, both sexes or all females, respectively. Egg temperature was linearly and negatively correlated with growth rate of both male and female juveniles. Thus, growth was enhanced, but not maximized, by male-producing egg temperatures. Egg temperature was also negatively correlated with juvenile temperature choice such that, on average, turtles from 21.5 degreesC eggs selected 28 degreesC water, while turtles from 30.5 degreesC eggs chose 24.5 degreesC water. Additionally, these temperature choices were highly repeatable, even following a 6 month hibernation period at 7 degreesC. Thus, while male egg temperatures do not directly maximize growth, multiple effects of embryonic temperature may combine to create long-lasting differences in the behavioral physiology of male and female C. serpentina. Such differences could be important to the ecology and evolution of TSD.


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