| disease associated with integumentary and cloacal parasites in tadpoles of northern red-legged frog rana aurora aurora. | a total of 6830 northern red-legged frog rana aurora aurora tadpoles were examined under a dissecting microscope for oral disc, integumentary, and cloacal abnormalities in 13 ponds in and near redwood national park in northern california. of these, 163 tadpoles were collected for histopathological investigation, including 115 randomly collected individuals, 38 collected with oral disc abnormalities, and 10 collected due to severe morbidity of unknown etiology. the tadpoles were infected with 8 p ... | 2007 | 18159674 |
| citizen scientists monitor a deadly fungus threatening amphibian communities in northern coastal california, usa. | ecoclub youth and supervising family members conducted citizen science to assess regional prevalence and distribution of batrachochytrium dendrobatidis (bd) among amphibians at humboldt bay national wildlife refuge (refuge) and redwood national and state parks (parks), humboldt county, california, us, may 2013 through december 2014. using quantitative real-time pcr, 26 (17%) of 155 samples were positive for bd. positive samples occurred in four frog and toad species: foothill yellow-legged frog ... | 2016 | 27195681 |
| 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 |
| a refined ecological risk assessment for california red-legged frog, delta smelt, and california tiger salamander exposed to malathion. | the california red-legged frog (crlf), delta smelt (ds), and california tiger salamander (cts) are 3 species listed under the united states federal endangered species act (esa), all of which inhabit aquatic ecosystems in california. the us environmental protection agency (usepa) has conducted deterministic screening-level risk assessments for these species potentially exposed to malathion, an organophosphorus insecticide and acaricide. results from our screening-level analyses identified potenti ... | 2017 | 29087623 |
| economic and ecological costs and benefits of streamflow augmentation using recycled water in a california coastal stream. | streamflow augmentation has the potential to become an important application of recycled water in water scarce areas. we assessed the economic and ecological merits of a recycled water project that opted for an inland release of tertiary-treated recycled water in a small stream and wetland compared to an ocean outfall discharge. costs for the status-quo scenario of discharging secondary-treated effluent to the ocean were compared to those of the implemented scenario of inland streamflow augmenta ... | 2013 | 23688175 |
| effects of flow regimes altered by dams on survival, population declines, and range-wide losses of california river-breeding frogs. | widespread alteration of natural hydrologic patterns by large dams combined with peak demands for power and water delivery during summer months have resulted in frequent aseasonal flow pulses in rivers of western north america. native species in these ecosystems have evolved with predictable annual flood-drought cycles; thus, their likelihood of persistence may decrease in response to disruption of the seasonal synchrony between stable low-flow conditions and reproduction. we evaluated whether a ... | 2012 | 22594596 |
| species boundaries, phylogeography and conservation genetics of the red-legged frog (rana aurora/draytonii) complex. | the red-legged frog, rana aurora, has been recognized as both a single, polytypic species and as two distinct species since its original description 150 years ago. it is currently recognized as one species with two geographically contiguous subspecies, aurora and draytonii; the latter is protected under the us endangered species act. we present the results of a survey of 50 populations of red-legged frogs from across their range plus four outgroup species for variation in a phylogenetically info ... | 2004 | 15315679 |