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Effects of ultraviolet radiation on toad early life stages

January 1, 2003


Exposure to harmful levels of ultraviolet-B radiation (UVB), a component of solar radiation, has been suggested as a potential cause of amphibian declines.


We measured solar radiation (UVB, ultraviolet-A, and visible) wavebands in breeding ponds of Bufo boreas (boreal toad, a montane species that has undergone severe population declines) and Bufo woodhousii (Woodhouse’s toad, a plains toad that has not experienced declines) and examined tolerances of these species to simulated solar UVB exposures in the laboratory.


We found larvae of both species to be tolerant of simulated solar UVB in excess of solar UVB levels observed in their breeding ponds. B. boreas tadpoles were more tolerant of simulated solar UVB exposure than B. woodhousii tadpoles, possibly because of greater amounts of photoprotective melanin in B. boreas skin.


UVB levels observed in B. boreas habitats do not currently appear to constitute a threat to the survival of these animals; however, long-term (>1 month) exposure to UVB levels comparable to levels associated with the water interface appears to reduce survival in B. woodhousii tadpoles. Therefore, future increases in surface and water column UVB radiation in bufonid habitats might pose significant survival risks to B. boreas or B. woodhousii populations.

Citation Information

Publication Year 2003
Title Effects of ultraviolet radiation on toad early life stages
DOI 10.1065/espr2002.06.123
Authors E. E. Little, R.D. Calfee, D. L. Fabacher, C. Carey, V. S. Blazer, E.M. Middleton
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Science and Pollution Research
Index ID 1014955
Record Source USGS Publications Warehouse
USGS Organization Leetown Science Center

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