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Freshwater wetlands are particularly vulnerable to climate change. Specifically, changes in temperature, precipitation, and evapotranspiration (i.e., climate drivers) are likely to alter flooding regimes of wetlands and affect the vital rates, abundance, and distributions of wetland‐dependent species. Amphibians may be among the most climate‐sensitive wetland‐dependent groups, as many species rely on shallow or intermittently flooded wetland habitats for breeding. Here, we integrated multiple years of high‐resolution gridded climate and amphibian monitoring data from Grand Teton and Yellowstone National Parks to explicitly model how variations in climate drivers and habitat conditions affect the occurrence and breeding dynamics (i.e., annual extinction and colonization rates) of amphibians. Our results showed that models incorporating climate drivers outperformed models of amphibian breeding dynamics that were exclusively habitat based. Moreover, climate‐driven variation in extinction rates, but not colonization rates, disproportionately influenced amphibian occupancy in monitored wetlands. Long‐term monitoring from national parks coupled with high‐resolution climate data sets will be crucial to describing population dynamics and characterizing the sensitivity of amphibians and other wetland‐dependent species to climate change. Further, long‐term monitoring of wetlands in national parks will help reduce uncertainty surrounding wetland resources and strengthen opportunities to make informed, science‐based decisions that have far‐reaching benefits.

Investigation of amphibian occupancy at potential breeding sites can provide information about the distribution and relative abundance of species, as well as insights into habitat relationships across large areas such as national parks. Based on previous research in the Greater Yellowstone Ecosystem (GYE), we hypothesized that the probability of amphibian occupancy increases with water conductivity. We conducted amphibian surveys with habitat measurements at 235 wetland sites in the GYE in 2002, thereby locating breeding populations of boreal toads (Anaxyrus boreas), boreal chorus frogs (Pseudacris maculata), Columbia spotted frogs (Lithobates luteiventris), and barred tiger salamanders (Ambystoma mavortium). Repeat surveys provided detection probabilities, which allowed for unbiased estimates of occupancy. The boreal chorus frog was the most common amphibian in the GYE, with breeding populations occupying approximately 48% of the sites, followed by Columbia spotted frog (35%), barred tiger salamander (14%), and boreal toad (13%). Occupancy corrected for detection probability averaged 36% higher (range 27%–50%) than naive estimates of occupancy. Detection rates ranged from 0.65 to 0.78 for the 4 species. Modeling of habitat covariates indicated that higher conductivity was positively associated with toad occupancy but negatively associated with chorus frog occupancy; Columbia spotted frog and barred tiger salamander occupancy was little influenced by water conductivity. Fish presence had a negative effect on occupancy of barred tiger salamanders and boreal chorus frogs. These results may help managers in the GYE manage and conserve important breeding habitat for amphibians, particularly if longterm monitoring efforts indicate declines in amphibian populations.

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 probability, 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 to 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 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, and 4940-19 690 ha for Columbia spotted frogs.

Monitoring of natural resources is crucial to ecosystem conservation, and yet it can pose many challenges. Annual surveys for amphibian breeding occupancy were conducted in Yellowstone and Grand Teton National Parks over a 4-year period (2006–2009) at two scales: catchments (portions of watersheds) and individual wetland sites. Catchments were selected in a stratified random sample with habitat quality and ease of access serving as strata. All known wetland sites with suitable habitat were surveyed within selected catchments. Changes in breeding occurrence of tiger salamanders, boreal chorus frogs, and Columbia-spotted frogs were assessed using multi-season occupancy estimation. Numerous a priori models were considered within an information theoretic framework including those with catchment and site-level covariates. Habitat quality was the most important predictor of occupancy. Boreal chorus frogs demonstrated the greatest increase in breeding occupancy at the catchment level. Larger changes for all 3 species were detected at the finer site-level scale. Connectivity of sites explained occupancy rates more than other covariates, and may improve understanding of the dynamic processes occurring among wetlands within this ecosystem. Our results suggest monitoring occupancy at two spatial scales within large study areas is feasible and informative.

This benchmark volume documents in comprehensive detail a major environmental crisis: rapidly declining amphibian populations and the disturbing developmental problems that are increasingly prevalent within many amphibian species. Horror stories on this topic have been featured in the scientific and popular press over the past fifteen years, invariably asking what amphibian declines are telling us about the state of the environment. Are declines harbingers of devastated ecosystems or simply weird reflections of a peculiar amphibian world? This compendium—presenting new data, reviews of current literature, and comprehensive species accounts—reinforces what scientists have begun to suspect, that amphibians are a lens through which the state of the environment can be viewed more clearly. And, that the view is alarming and presages serious concerns for all life, including that of our own species. The first part of this work consists of more than fifty essays covering topics from the causes of declines to conservation, surveys and monitoring, and education. The second part consists of species accounts describing the life history and natural history of every known amphibian species in the United States.

The availability and utility of Geographical Information Systems (GIS) has increased greatly within the past 20 years. For general descriptions of GIS, see Clarke (1997), Heywood et al. (1998), and Krzysik (1998a). In the past, GIS required expensive workstations, software that was difficult to use, expert technicians, and considerable resources for acquiring spatial data in a digital format. Now, systems using relatively inexpensive desktop computers and programs (e.g., ArcView) have the ability to perform many workstation GIS functions. The software is easier to use, training is widely available, and large amounts of spatial data in digital format can be obtained

The recent declines and disappearance of many amphibian populations around the world appear to have multiple potential causes. The use of former studies as baselines for determining the extent and causes of declines has been recommended by the National Research Council. In the Greater Yellowstone Ecosystem, only one detailed historical study of an amphibian population exists. Frederick B. Turner of the University of California, Berkeley, conducted an intensive mark-recapture study of spotted frogs (Rana pretiosa, now Rana luteiventris) in Yellowstone National Park, 1953-1955. Turner observed in 1991 that the population appeared to have undergone a sharp decline. The objectives of this research were to verify and describe the suspected decline, to describe ecological changes since the 1950, and to determine the causes of the decline. The approach was to replicate Turner's investigation and to compare demographic and spatial characteristics. Two main hypotheses for the decline were adverse weather patterns and habitat changes. The spotted frog population occupying the study area has declined about 78% since the 1950s. Environmental changes have occurred and are largely due to human activities in the area. Patterns of spatial relationships exhibited by frogs have changed, including activity ranges, dispersion, distribution, and seasonal movements. The most important factors contributing to the current small population size appear to be related to habitat. Alterations of spatial relationships indicate specific changes in the locations, quality, importance, and connectivity of habitat features. Overwintering, foraging, and breeding areas have been affected, and habitat diversity has been lost. Habitat modifications implicated as the main causes of habitat problems resulted from a water pumping system installed at the headwater springs in the 1980s and reconstruction of the Grand Loop Highway in the early 1970s. Management actions could bolster the chances that this population will persist in the future.