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(i) This dataset presents macroscopic and microscopic pathological findings and bacteriology of 178 tadpoles diagnosed with Severe Perkinsea Infections. (ii) Specimen were collected and submitted to the NWHC as part of mortality investigations and collection of specimen from apparently healthy populations as part of ongoing amphibian health monitoring. (iii) Necropsies and gross evaluation of carcasses were carried out under a dissecting microscope. (iv) Severe Perkinsea Infection was confirmed in each specimen by histological observation of pathological changes in tissues with presence of Perkinsea-like organisms in at least one organ, including brain, eyes, gastrointestinal tract, gills, heart, liver, lungs, kidney,...
From 2003-2018, USGS researchers and collaborators conducted mark-recapture studies of the boreal toad at the Lost Trail National Wildlife Refuge in northwestern Montana, USA. The datasets included here contain information on individual toad capture history, body size, and disease status. These data were collected annually over the 16-year period at up to 11 breeding sites per year on the refuge. We include datasets for (1) male toad captures over time, (2) female toad captures over time, (3) male disease status (tested - positive or negative, or not tested in a given year), (4) all toad length and weight data over time, and (5) male toad size and body condition over time.
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Amphibians living in agricultural areas encounter many challenges. Two factors affecting individuals in these landscapes are habitat loss and pesticides. This thesis focuses on amphibians using agricultural wetlands in Iowa, where row crops such as corn and soybeans dominate the landscape. The goal of my first study was to determine the influences of site characteristics on amphibian presence and success. I used occupancy analysis to estimate proportion of area occupied by four species as a function of eight covariates hypothesized to affect occupancy: fish abundance, salamander abundance, invertebrate density, vegetative cover, wetland area, water atrazine concentration, surrounding crop land use, and overall wetland...
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Occupancy models provide a reliable method of estimating species distributions while accounting for imperfect detectability. The cost of accounting for false absences is that detection and nondetection surveys typically require repeated visits to a site or multiple-observer techniques. More efficient methods of collecting data to estimate detection probabilities would allow additional sites to be surveyed for the same amount of effort, which would support more precise estimation of covariate effects to improve inference about underlying ecological processes. Time-to-detection surveys allow the estimation of detection probability based on a single site visit by one observer, and therefore might be an efficient technique...
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California Red-legged Frogs (Rana draytonii) are typically regarded as inhabitants of permanent ponds, marshes, and slow-moving streams, but their ecology in other habitats, including coastal dunes, remains obscure. To avoid and minimize potential negative effects of dune restoration activities, we studied the spatial ecology, habitat selection, and survival of California Red-legged Frogs in coastal dune drainages at Point Reyes National Seashore, California. Frogs remained in their home drainages throughout the summer, and, with some notable exceptions, most remained close to water. Home ranges of California Red-legged Frogs in dunes were generally small, and they selected areas near water with logs that served...


    map background search result map search result map California Red-Legged Frogs in Point Reyes coastal dune drainages (2015) Amphibian Occupancy and Effects of Habitat Use on Pesticide Exposure in Iowa Wetlands Time to detection data for Point Reyes pond-breeding amphibians, 2017 Pathology and bacteriology of 178 tadpoles with histologically confirmed Severe Perkinsea Infections: Data Mark-recapture data for a boreal toad metapopulation at the Lost Trail National Wildlife Refuge, Montana (2003-2018) California Red-Legged Frogs in Point Reyes coastal dune drainages (2015) Mark-recapture data for a boreal toad metapopulation at the Lost Trail National Wildlife Refuge, Montana (2003-2018) Time to detection data for Point Reyes pond-breeding amphibians, 2017 Pathology and bacteriology of 178 tadpoles with histologically confirmed Severe Perkinsea Infections: Data