Geology topics

Charles R. Peterson

Publications and source records attributed to Charles R. Peterson.

4 recordsLinked to original sources

USGS2026

Amphibian use of recently created wetlands in the Palouse region of northern Idaho, USA

Human development has resulted in the loss of natural wetlands in many regions and thus has led to amphibian habitat loss. Human-constructed wetlands are increasingly prevalent, particularly in human-modified landscapes, and can be used as breeding habitats by amphibians. It is important to identify factors influencing amphibian use of constructed wetlands to guide future wetland creation efforts. We examined wetland- and landscape-level factors influencing the presence and reproduction of native amphibians in 33 recently created (2–11 yold) wetlands within an urban-agricultural interface in northern Idaho, USA. We recorded wetland age, perimeter vegetation, and percentage of surrounding land cover as covariates and modeled detection and occupancy using Bayesian Multi-scale Occupancy Models for the three species we detected: Sierran Treefrog ( Pseudacris sierra ), Colombia Spotted Frog ( Rana luteiventris ), and Long-Toed Salamander ( Ambystoma macrodactylum ). Our results indicate that these three species can rapidly colonize recently created wetlands in an urban-agricultural interface. The effects of wetland- and landscape-scale features varied across species. Colombia Spotted Frog occupancy was greatest in older wetlands with some evidence for a negative association with more urbanized landscapes. Long Toed Salamanders and Sierran Treefrogs were not associated with wetland age but also showed some evidence of negative associations with urbanization. Long-Toed Salamanders showed evidence of using less vegetated wetlands while Sierran Treefrogs showed evidence of using more vegetated wetlands. Our results are consistent with multiple studies showing that wetlands in human-modified landscapes can provide amphibian breeding habitat, and they suggest that including vegetation plantings within recently created wetlands may promote amphibian colonization. Anecdotal observations also indicate that designing wetlands with sufficient hydroperiod for metamorphoses may be important for ensuring that newly created wetlands benefit amphibian populations.

Idaho↗

USGS2016

Amphibian mortality events and ranavirus outbreaks in the Greater Yellowstone Ecosystem

Mortality events in wild amphibians go largely undocumented, and where events are detected, the numbers of dead amphibians observed are probably a small fraction of actual mortality (Green and Sherman 2001; Skerratt et al. 2007). Incidental observations from field surveys can, despite limitations, provide valuable information on the presence, host species, and spatial distribution of diseases. Here we summarize amphibian mortality events and diagnoses recorded from 2000 to 2014 in three management areas: Yellowstone National Park; Grand Teton National Park (including John D. Rockefeller, Jr. Memorial Parkway); and the National Elk Refuge, which together span a large portion of protected areas within the Greater Yellowstone Ecosystem (GYE; Noss et al. 2002). Our combined amphibian monitoring projects (e.g., Gould et al. 2012) surveyed an average of 240 wetlands per year over the 15 years. Field crews recorded amphibian mortalities during visual encounter and dip-netting surveys and collected moribund and dead specimens for diagnostic examinations. Amphibian and fish research projects during these years contributed additional mortality observations, specimens, and diagnoses.

Greater Yellowstone Ecosystem↗

USGS2011

Predicting breeding habitat for amphibians: a spatiotemporal analysis across Yellowstone National Park

The ability to predict amphibian breeding across landscapes is important for informing land management decisions and helping biologists better understand and remediate factors contributing to declines in amphibian populations. We built geospatial models of likely breeding habitats for each of four amphibian species that breed in Yellowstone National Park (YNP). We used field data collected in 2000-2002 from 497 sites among 16 basins and predictor variables from geospatial models produced from remotely sensed data (e.g., digital elevation model, complex topographic index, landform data, wetland probabililty, and vegetative cover). Except for 31 sites in one basin that were surveyed in both 2000 and 2002, all sites were surveyed once. We used polytomous regression to build statistical models for each species of amphibian from 1) field survey site data only, 2) field data combined with data from geospatial models, and 3) data from geospatial models only. Based on measures of receiver operating characteristic (ROC) scores, models of the second type best explained likely breeding habitat because they contained the most information (ROC values ranged from 0.70 - 0.88). However, models of the third type could be applied to the entire YNP landscape and produced maps that could be verified with reserve field data. Accuracy rates for models built for single years were highly variable, ranging from 0.30 to 0.78. Accuracy rates for models built with data combined from multiple years were higher and less variable, ranging from 0.60 to 0.80. Combining results from the geospatial multiyear models yielded maps of "core" breeding areas (areas with high probability values for all three years) surrounded by areas that scored high for only one or two years, providing an estimate of variability among years. Such information can highlight landscape options for amphibian conservation. For example, our models identify alternative for areas that could be protected for each species, including 6828-10 764 ha for tiger salamanders; 971-3017 ha for western toads; 4732-16 696 ha for boreal chorus frogs; 4940-19 690 hectares for Columbia spotted frogs.

Yellowstone National Park↗

USGS2006

Taxonomic and geographic variation in oviposition by tailed frogs ( Ascaphus spp )

Tailed frogs ( Ascaphus spp.) oviposit in cryptic locations in streams of the Pacific Northwest and Rocky Mountains. This aspect of their life history has restricted our understanding of their reproductive ecology. The recent split of A. montanus in the Rocky Mountains from A. truei was based on molecular differentiation, and comparisons of their ecology are limited. Our objectives were to provide a range-wide summary of information on Ascaphus oviposition, compare some aspects of the reproductive ecology of the 2 species, and examine geographic variation in their reproductive traits. Reproductive ecology of the 2 species differed. Ascaphus truei had smaller clutches, oviposited later in the summer, and had a longer duration of oviposition than A. montanus . A greater number of communal oviposition sites were attributed to A. montanus . These ecological differences support the recent taxonomic revision of Ascaphus and suggest that different management strategies may be necessary for each species where conservation is a priority.

Northwestern Naturalist↗