The Canadian Field-Naturalist (E-Journal)
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A resurvey of a Wood Turtle (Glyptemys insculpta) population in northern New Hampshire, USA, after 13 years
Get PDFPopulations of Wood Turtle (Glyptemys insculpta) have declined across the species’ range. We surveyed a protected Wood Turtle population in northern New Hampshire in 2007 and again in 2020 to determine whether the size of the population had changed and the average annual survival rate between the two periods. We used closed-population loglinear models to estimate the adult population size in 2007 and 2020 and, for the subset of turtles captured in both years, to estimate the rate of survival. Based on these models, we found an adult population of 56 (95% CI 33–126) in 2007 and 46 (95% CI 31–85) in 2020; we did not detect a statistically significant difference between the two population estimates. In addition, we estimated a 96% average annual adult survival rate and determined this rate could be no lower than 92%. This information provides useful baseline data and will help inform future monitoring and threat mitigation work for this population
"Biology and Conservation of the Wood Turtle" edited by Michael T. Jones and Lisabeth L. Willey, 2021. [book review]
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First evidence of White-footed Deer Mouse (Peromyscus leucopus) on mainland New Brunswick, Canada
Get PDFWhite-footed Deer Mouse (Peromyscus leucopus) and the closely related, and more northerly ranging, Deer Mouse (Peromyscus maniculatus) broadly overlap in distribution and are often difficult to distinguish from each other. Based on molecular genetic data (cytochrome b gene), we report two new distribution records for P. leucopus for New Brunswick, Canada, the first mainland localities for this species in the province. Previous sampling of Peromyscus in New Brunswick may have overlooked the presence of P. leucopus, possibly because the specimens collected were all assumed to be P. maniculatus. However, current detection in New Brunswick may be part of a broader recent northward range expansion documented to be underway in P. leucopus. Although our use of a single mitochondrial gene to identify P. leucopus does not eliminate the possibility that the New Brunswick specimens are of hybrid origin, our results support the presence of P. leucopus in New Brunswick and suggest more detailed analyses will be required to determine the nature of any genetic interaction between P. leucopus and P. maniculatus in the province. Recognition of morphologically cryptic Peromyscus in southern New Brunswick also emphasizes the need to incorporate comprehensive methods to ensure the correct identification of specimens of this genus in Maritime Canada. We also note the potential implications of this discovery with respect to the incidence of Lyme disease in New Brunswick
Apparent winterkill of Painted Turtle (Chrysemys picta)
Get PDFAround the margin of an artificial pond in Ottawa, Ontario, we found 25 Painted Turtles (Chrysemys picta) that appeared to have died over the course of two winters (17 during the first winter and eight during the second). We examined meteorological data to try to determine the cause of the mortality. Summer and fall rains were only slightly below normal in both years, suggesting water levels should have been close to normal. The winter air temperature was warmer than normal and winter snowfall was slightly above normal in both years. Unseasonable weather does not appear to be responsible for the winter mortality and the pond’s maximum depth of 1.7 m should prevent freezing to the bottom. It is possible that the artificial nature of the pond creates suboptimal overwintering habitat, rendering the site an ecological trap; however, there is no direct evidence to support this theory. It is also possible that winter mortality of turtles is widespread at temperate wetlands, but that dead turtles were more detectable at this site because of the bare shoreline around the pond. Winter mass mortality events, if common, may represent an additional threat to turtle populations, which are declining from various anthropogenic threats
