Spatial Ecology and Population Genetics of Northern Map Turtles (Graptemys geographica) in Fragmented and Continuous Habitats in Canada

2010 ◽  
Vol 9 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Amanda M. Bennett ◽  
Matthew Keevil ◽  
Jacqueline D. Litzgus
2009 ◽  
Vol 43 (4) ◽  
pp. 597-604 ◽  
Author(s):  
Marie-Andrée Carrière ◽  
Grégory Bulté ◽  
Gabriel Blouin-Demers

2013 ◽  
Vol 91 (8) ◽  
pp. 581-588 ◽  
Author(s):  
Nicola Banger ◽  
Gabriel Blouin-Demers ◽  
Grégory Bulté ◽  
Stephen C. Lougheed

Sexual selection theory predicts that males should be promiscuous to maximize their reproductive success, while females should be choosy. Yet females of many taxa often produce progeny sired by multiple males, indicating that promiscuity can be important for the reproductive success of females. Promiscuity may enhance the fitness of females if it increases the genetic quality, or the genetic variety, and thus the viability of their offspring. We quantified the number of sires per clutch in a population of Northern Map Turtles (Graptemys geographica (LeSueur, 1817)) in Lake Opinicon, Ontario, Canada, and tested whether the number of sires affects several metrics of viability in hatchlings. Based on the most conservative estimate, at least 71% of clutches in this population are sired by multiple males, but there was no evidence that larger clutches are sired by more males. Clutches sired by more males had higher hatching success and survival, but the differences were not statistically significant. We did not find any effect of the number of sires on hatchling morphology or locomotor performance. Collectively, our results partially support the hypothesis that promiscuity can increase the reproductive success of female Northern Map Turtles.


2015 ◽  
Vol 129 (1) ◽  
pp. 80 ◽  
Author(s):  
Jordan Catrysse ◽  
Emily Slavik ◽  
Jonathan Choquette ◽  
Ashley E. Leifso ◽  
Christina M. Davy

We report a mass mortality of Northern Map Turtles (Graptemys geographica [LeSueur, 1817]) on the north shore of Lake Erie, Ontario, Canada. Thirty-five dead adult females were recovered from a nesting area over a period of four weeks. Predation and boat strikes were both excluded as potential cause of death, but the actual cause could not be determined because of the poor condition of the carcasses. Other possible explanations for the mortality include poisoning, drowning, and infection with an unidentified pathogen. Mass mortality in long-lived species, such as turtles, can have long-term effects on population growth and is a cause for concern in a species at risk.


2019 ◽  
Vol 132 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Sue Carstairs ◽  
Marc Dupuis-Desormeaux ◽  
Christina M. Davy

Road mortality poses a major threat to turtle populations. Several studies have suggested that the terrestrial movements associated with nesting increase this risk for females. The Ontario Turtle Conservation Centre (OTCC) is home to the Kawartha Turtle Trauma Centre, which admits 900 or more turtles a year, with road injuries the primary cause of admission. We tested the hypothesis that road mortality in turtles is female-biased using data from injured Midland Painted Turtles (Chrysemys picta marginata), Snapping Turtles (Chelydra serpentina), Blanding’s Turtles (Emydoidea blandingii), and Northern Map Turtles (Graptemys geographica) collected over about 126 000 km2 and admitted to OTCC’s hospital from January 2013 to October 2017. There was no difference in the number of male and female admissions of Midland Painted, Blanding’s, or Snapping Turtles (P > 0.05); however, more female Northern Map Turtles than males were admitted (P < 0.001). Admission of female turtles peaked in June during the nesting season, but male admissions were more evenly distributed throughout the season. Our admissions data provide a temporally unbiased and geographically broad snapshot of turtle–vehicle interactions that can directly inform conservation and management policies. Although our data are not equivalent to mortality rates, these results demonstrate that vehicle strikes can have a substantial impact on both female and male turtles.


1988 ◽  
Vol 22 (2) ◽  
pp. 152 ◽  
Author(s):  
Thomas G. Pluto ◽  
Edward D. Bellis

2020 ◽  
Vol 98 (3) ◽  
pp. 229-235
Author(s):  
Sarah V. Langer ◽  
Carolyn M. Kapron ◽  
Christina M. Davy

Development in oviparous reptiles requires the correct formation and function of extra-embryonic membranes in the egg. In 2017, we incubated 2583 eggs from five species of freshwater turtle during a long-term ecological study and opened eggs that failed to hatch. We described a previously unreported developmental anomaly: the retention of an extra-embryonic membrane around 7 turtles (1 Spiny Softshell Turtle (Apalone spinifera (Le Sueur, 1827)), 1 Snapping Turtle (Chelydra serpentina (Linnaeus, 1758)), and 5 Northern Map Turtles (Graptemys geographica (Le Sueur, 1817))) that were alive but unhatched >14 days after their clutch mates had emerged. We investigated the association between retention of this membrane and the exhibition of other developmental deformities of varying severity, and we tested whether this novel abnormality was associated with reduced fertility or hatching success in affected clutches. Consultation of ∼150 years of literature suggests that we observed persistence of the chorioallantoic membrane (CAM; also called the chorioallantois). Our data suggest that clutches where at least one turtle exhibits a persistent CAM may also exhibit slightly reduced fertility or hatch success in the rest of the clutch compared with conspecific clutches that do not contain this anomaly. Future research should investigate the factors predicting CAM retention and other developmental abnormalities.


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