| Affiliation: | (1) Department of Environmental and Forest Biology, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210, USA;(2) School of Biological Sciences, University of Hong Kong, Hong Kong, SAR, China |
| Abstract: | Despite an increasing understanding of the effects of roadways on amphibian populations, no studies have examined road effects on demographic traits other than survival. We predicted that road mortality could exert a disproportionate effect on fecundity in long-lived species due to shifts in population age structures to younger individuals of smaller size that produce commensurately smaller egg masses. To test this hypothesis, we assessed egg mass sizes of a long-lived amphibian (spotted salamander, Ambystoma maculatum) and short-lived one (wood frog, Rana sylvatica) in wetlands near and far from highways. Egg mass sizes of A. maculatum were smaller in wetlands near highways. In contrast, those of R. sylvatica were similar among wetlands regardless of the distance from highways. We conclude that paved highways with moderate traffic volume may be having important effects on populations of long-lived amphibians through mortality-mediated depression of reproduction. |
