| the genetics of amphibian declines: population substructure and molecular differentiation in the yosemite toad, bufo canorus (anura, bufonidae) based on single-strand conformation polymorphism analysis (sscp) and mitochondrial dna sequence data. | we present a comprehensive survey of genetic variation across the range of the narrowly distributed endemic yosemite toad bufo canorus, a declining amphibian restricted to the sierra nevada of california. based on 322 bp of mitochondrial cytochrome b sequence data, we found limited support for the monophyly of b. canorus and its closely related congener b. exsul to the exclusion of the widespread western toad b. boreas. however, b. exsul was always phylogenetically nested within b. canorus, sugg ... | 2000 | 10736023 |
| pesticides are involved with population declines of amphibians in the california sierra nevadas. | several species of frogs and toads are in serious decline in the sierra nevada mountains of california. these species include the threatened red-legged frog ( rana aurora ), foothill yellow-legged frog ( r. boylii ), mountain yellow-legged frog ( r. muscosa ), cascades frog ( rana cascadae ), western toad ( bufo boreas ) and yosemite toad ( b. canorus ). for many of these species current distributions are down to 10% of historical ranges. several factors including introduced predators, habitat l ... | 2001 | 12805670 |