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Anthropogenic salinization is a pervasive pollutant in much of the northeastern United States because of the widespread use of chemical deicing agents on roads. Although studies have examined the physiological effects of salinization on amphibians across life stages, behavioral responses to salinization of habitats are less studied. In this study, we experimentally test how salinity and temperature conditions experienced as larvae affect behavioral and physiological responses as juveniles. We first experimentally test whether juvenile Wood Frogs (Lithobates sylvaticus) can detect and avoid road salt in terrestrial soils and whether this avoidance behavior differs depending on temperature and salinity conditions in which individuals were raised as larvae. We also experimentally test whether temperature and salinity conditions experienced as larvae affect desiccation rates in juvenile Wood Frogs. We found a significant correlation between larval salinity conditions and choice of soil, with frogs raised in high salt aquatic conditions spending the majority of time on high salinity soils and frogs raised in low salt aquatic conditions spending the majority of time on low salinity soils. This behavioral response was muted in frogs raised in elevated temperature conditions. We were unable to detect a correlation between larval treatment and desiccation rate. Our experiments demonstrate that Wood Frogs can detect and respond to salinity levels in terrestrial habitats and that this juvenile response depends on environmental conditions experienced as larvae.
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Fitter frogs from polluted ponds: The complex impacts of human‐altered environments
Abstract 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.
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- Award ID(s):
- 1655092
- PAR ID:
- 10441413
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Evolutionary Applications
- Volume:
- 12
- Issue:
- 7
- ISSN:
- 1752-4571
- Page Range / eLocation ID:
- p. 1360-1370
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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