| helminths of two native frog species (rana chiricahuensis, rana yavapaiensis) and one introduced frog species (rana catesbeiana) (ranidae) from arizona. | the gastrointestinal tracts, lungs, urinary bladders, and body cavities of rana catesbeiana (n = 25), rana chiricahuensis (n = 25), and rana yavapaiensis (n = 37) from arizona were examined for helminths. helminths representing 9 species of trematodes: cephalogonimus brevicirrus, glypthelmins quieta, gorgoderina attenuata, haematoloechus complexus, haematoloechus langiplexus, megalodiscus temperatus, alaria sp., clinostomum sp., and an unidentified strigeid; and 4 species of nematodes: falcaustr ... | 1998 | 9488361 |
| chytridiomycosis in native arizona frogs. | twenty-seven adult/sub-adult lowland leopard frogs (rana yavapaiensis), two larval lowland leopard frogs, two adult chirichahua leopard frogs (rana chiricahuensis), and two adult canyon tree frogs (hyla arenicolor) collected from populations experiencing mortality events at eight sites were found to have characteristic lesions of chytrid fungus infection (batrachochytrium dendrobatidis). the mortalities occurred during december 1992 and between october and february in 1997-98 and december and fe ... | 2002 | 11838218 |
| characterization of antimicrobial peptides in skin secretions from discrete populations of lithobates chiricahuensis (ranidae) from central and southern arizona. | populations of the chiricahua leopard frog lithobates chiricahuensis (ranidae) occupying regions in southern arizona (southern range) are morphologically distinct from those from the mogollon rim of central arizona (northern range) and a comparison of dna sequences of mitochondrial genes has suggested that they may represent separate species. peptidomic analysis of norepinephrine-stimulated skin secretions has led to the identification of six peptides with antimicrobial activity in samples from ... | 2011 | 21262304 |
| toxicity of cadmium, copper, and zinc to the threatened chiricahua leopard frog (lithobates [rana] chiricahuensis). | the chiricahua leopard frog (lithobates chiricahuensis) is in decline throughout the western united states, and is particularly sensitive to physical, chemical and biotic changes in their habitat. acute toxicity tests revealed that among the metals detected in chiricahua leopard frog habitat, copper was toxic at concentrations lower than those observed in the environment. developing tadpoles were chronically exposed for 60 days to cadmium, copper and zinc because of the potential for long term e ... | 2017 | 29098305 |
| a statistical forecasting approach to metapopulation viability analysis. | conservation of at-risk species is aided by reliable forecasts of the consequences of environmental change and management actions on population viability. forecasts from conventional population viability analysis (pva) are made using a two-step procedure in which parameters are estimated, or elicited from expert opinion, and then plugged into a stochastic population model without accounting for parameter uncertainty. recently developed statistical pvas differ because forecasts are made condition ... | 2020 | 31709679 |
| increasing connectivity between metapopulation ecology and landscape ecology. | metapopulation ecology and landscape ecology aim to understand how spatial structure influences ecological processes, yet these disciplines address the problem using fundamentally different modeling approaches. metapopulation models describe how the spatial distribution of patches affects colonization and extinction, but often do not account for the heterogeneity in the landscape between patches. models in landscape ecology use detailed descriptions of landscape structure, but often without cons ... | 2018 | 29453767 |