Data from: Fitter frogs from polluted ponds: the complex impacts of human-altered environments

Human-modified habitats rarely yield outcomes that are aligned with
conservation ideals. Landscapes that are subdivided by roads are no
exception, precipitating negative impacts on populations due to
fragmentation, pollution, and road kill. Although many populations in
human modified habitats show evidence for local adaptation, rarely does
environmental change yield outright benefits for populations of
conservation interest. Contrary to expectations, we report surprising
benefits experienced by amphibian populations breeding and dwelling in
proximity to roads. We show that roadside populations of the wood frog,
Rana sylvatica, exhibit better locomotor performance and higher measures
of traits related to fitness compared with frogs from less disturbed
environments located further away from roads. These results contrast
previous evidence for maladaptation in roadside populations of wood frogs
studied elsewhere. Our results indicate that altered habitats might not be
unequivocally detrimental, and at times might contribute to metapopulation
success. While the frequency of such beneficial outcomes remains unknown,
their occurrence underscores the complexity of inferring consequences of
environmental change.