Amphibians were present in 118 potential breeding sites 9–66 km northeast and southwest of Sudbury, Ontario. Detailed chemical analyses were done for 38 ponds, and 23 variables were subjected to principal components analysis to summarize the main gradients in pond chemistry. Discriminant analysis using scores of the first three principal components showed that the presence of Rana pipiens, R. clamitans and Hyla crucifer was positively related to buffering status (alkalinity, pH, and other correlated variables); the presence of H. crucifer was also negatively related to atmospheric deposition status (cadmium, nickel, other correlated metals, and sulphate). Discriminant analysis using the original water chemistry variables confirms these general patterns. Two species show relationships with buffering status variables: Rana sylvatica with conductivity and R. clamitans with alkalinity. Three species also show negative correlation with metal levels in pond water: Bufo americanus with nickel, R. clamitans with aluminum, and R. pipiens with zinc. Although most of the species expected do occur in the Sudbury area, the distributions of several species appear related to buffering status and metals present in their immediate environemnt. There were only two observations of Ambystoma maculatum, and low numbers of egg masses were noted for R. sylvatica.
To assess whether Western Chorus Frogs have declined in eastern Ontario, we conducted amphibian call surveys at 18 sites in the Cornwall area, where they were heard calling in 1990, as well as selected wetlands in the same area. Chorus frogs were detected at only 1 of the 18 original locations during surveys in 2001 and 2007. When survey locations with and without Chorus Frogs were considered, the site occupancy rate declined from 58% in 1990, to only 12% in 2007. Chorus Frogs appear to have declined in this area of eastern Ontario which is adjacent to documented declines in western Québec and northern New York.
A Lake Erie population of Emydoidea blandingii produced clutches of slightly greater relative mass than those of other emydids. Regression analyses showed that both clutch mass and relative clutch mass were significantly related to both female mass and female size, while clutch size was also related to female size. Mean egg mass was not related to either clutch size or female size.
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