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Many research studies have focused on the interactions among larval anurans, but relatively little is known about competitive or predatory interactions among anurans following metamorphosis. The purpose of our study was to examine the effects of post-metamorphic green frogs (Rana damitans) on post-metamorphic American toads (Bufo americanus) in the terrestrial environment as a model for understanding how interspecific differences in size at metamorphosis may influence terrestrial interactions. We examined if caged, uncaged or no green frogs affected survival, growth and hiding behavior of recently metamorphosed American toads in a replicated laboratory experiment. Green frogs did not appear to prey upon small American toads. However, by the end of the experiment American toad survival was lowest in treatments with uncaged green frogs; this result suggests that green frogs may outcompete American toads for food, but such impacts in nature may be limited or may have selected for spatial segregation in the terrestrial environment. Green frogs also increased hiding activity of toads at some times, which may in part explain the trend of reduced mass gained when toads were reared with green frogs. This study represents one of the first to examine interspecific interactions among anurans with complex life cycles in the terrestrial environment., INTRODUCTION Amphibians with complex life cycles have different strategies to deal with biotic and abiotic pressures in aquatic and terrestrial environments (Wilbur and Collins, 1973; Werner, 1986). Alterations in length [...]

Genetic differences were documented among four wintering flocks of the eastern wild turkey (Meleagris gallopavo silvestris) located on the Savannah River Site in Aiken County, South Carolina. Five of 19 loci were polymorphic based on electrophoretic analysis of blood tissue. Allele frequency analysis and F-statistics revealed small but significant genetic differences among flocks. The maintenance of genetic subdivision among flocks was largely attributed to the breeding structure and dispersal behavior of the wild turkey., INTRODUCTION The wild turkey declined drastically in number between the 18th century European settlement of the Americas and the 20th century (Bent, 1963; Leberg, 1991). The eastern wild turkey (Meleagris [...]

Abstract: We exposed Blanchard's cricket frogs (Acris blanchardi) to ecologically relevant concentrations (0, 0.1, 1, and 10 μg/L) of a commercial formulation of atrazine throughout the larval period to determine effects on survival, somatic growth and development (time to metamorphosis and mass at metamorphosis), and gonadal development (sex ratio at metamorphosis and the prevalence of testicular ova in phenotypic males). We tested the following hypotheses: 1) atrazine feminizes the sex ratio, 2) atrazine increases the proportion of phenotypic males with testicular ova, and 3) atrazine differentially affects somatic growth (mass at metamorphosis) and development (time to metamorphosis) for males and females. Although the control sex ratio was male‐biased, exposure to 0.1 and 10 μg/L atrazine feminized sex ratios, because these treatments produced 51 and 55% fewer males than the control, respectively. We did not observe testicular ova. Atrazine did not impact survival or metamorphosis, and we did not detect sexually dimorphic impacts on time to metamorphosis or mass at metamorphosis. However, males metamorphosed 2.3 d later than females, regardless of treatment. Sex biases in timing of metamorphosis are underexplored in anurans, but if prevalent, could have important implications for theory surrounding the impact of environmental factors on metamorphosis. Our data suggest that cricket frog sex ratios are sensitive to environmentally relevant concentrations of atrazine and that feminization in the field is likely. Environ Toxicol Chem 2018;37:427–435. © 2017 SETAC [ABSTRACT FROM AUTHOR]