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The recently identified pathogenic chytrid fungus, Batrachochytrium salamandrivorans (Bsal), poses a severe threat to the distribution and abundance of salamanders within the United States and Europe. Development of a response strategy for the potential, and likely, invasion of Bsal into the United States is critical to protect global salamander biodiversity. A formal working group, led by Amphibian Research and Monitoring Initiative (ARMI) scientists from the U.S. Geological Survey (USGS) Patuxent Wildlife Research Center, Fort Collins Science Center, and Forest and Rangeland Ecosystem Science Center, was held at the USGS Powell Center for Analysis and Synthesis in Fort Collins, Colorado, USA from June 23 to June 25, 2015, to identify critical Bsal research and monitoring needs that could inform conservation and management strategies for salamanders in the United States. Key findings of the workshop included the following: (1) the introduction of Bsal into the United States is highly probable, if not inevitable, thus requiring development of immediate short-term and long-term intervention strategies to prevent Bsal establishment and biodiversity decline; (2) management actions targeted towards pathogen containment may be ineffective in reducing the long-term spread of Bsal throughout the United States; and (3) early detection of Bsal through surveillance at key amphibian import locations, among high-risk wild populations, and through analysis of archived samples is necessary for developing management responses. Top research priorities during the pre-invasion stage included the following: (1) deployment of qualified diagnostic methods for Bsal and establishment of standardized laboratory practices, (2) assessment of susceptibility for amphibian hosts (including anurans), and (3) development and evaluation of short- and long-term pathogen intervention and management strategies. Several outcomes were achieved during the workshop, including development of an organizational structure with working groups for a Bsal Task Force, creation of an initial influence diagram to aid in identifying effective management actions in the face of uncertainty, and production of a list of potential management actions and key research uncertainties. Additional products under development include a Bsal Strategic Action plan, an emergency response plan, a monitoring and surveillance program, a standardized diagnostic approach, decision-models for natural resource agencies, and a reporting database for salamander mortalities. This workshop was the first international meeting to address the threat of Bsal to salamander populations in the United States, with more than 30 participants from U.S. conservation and resource management agencies (USFWS, USFS, DoD, NPS, and AFWA) and academic research institutions from Australia, the Netherlands, Switzerland, the United Kingdom, and the United States.

The primary goal of the Trinity River Restoration Program (TRRP) is to rehabilitate the fisheries on the dam-controlled Trinity River; however, maintaining and enhancing other wildlife populations through the restoration initiatives is also a key objective. For herpetological species, foothill yellow-legged frogs and western pond turtles have been identified as important species on which to focus monitoring efforts due to their status as California state-listed Species of Concern and potential listing on the U.S. Endangered Species List. We have developed and implemented a monitoring strategy for these species specific to the Trinity River with the objective of establishing baseline values for probabilities of site occupancy, colonization and local extinction; identify site characteristics that correlate with the probability of extinction; and to estimate overall trends in abundance. Our three-year study suggests that foothill yellow-legged frogs declined in the probability of site occupancy. Conversely, our results suggest that western pond turtle increased in both abundance and the probability of site occupancy. The short length of our study period makes it difficult to draw firm conclusions, however these result provide needed baseline data. Further monitoring and directed studies are required to assess how habitat changes and management decisions relate to the status and trend of these species.

ARMI is uniquely qualified to provide information that is scalable from local to national levels and is useful to resource managers. Here we provide highlights and significant milestones of this innovative program. ARMI has now produced over 500 publications. We feature several in this fact sheet, but please visit our website (http://armi.usgs. gov) for additional information on ARMI products, to find summaries of research topics, or to search for ARMI activities in your area.

Beavers (Castor canadensis) influence habitat for many species and pose challenges in developed landscapes. They are increasingly viewed as a cost?efficient means of riparian habitat restoration and water storage. Still, information on their status is rare, particularly in western North America. We used aerial photography to evaluate changes in beaver occupancy between 1942–1968 and 2009 in upper portions of 2 large watersheds in Oregon, USA. We used multiple observers and occupancy modeling to account for bias related to photo quality, observers, and imperfect detection of beaver impoundments. Our analysis suggested a slightly higher rate of beaver occupancy in the upper Deschutes than the upper Klamath basin. We found weak evidence for beaver increases in the west and declines in eastern parts of the study area. Our study presents a method for dealing with observer variation in photo interpretation and provides the first assessment of the extent of beaver influence in 2 basins with major water?use challenges. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating panel frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are decreasing in probability of both site occupancy and abundance. We did not find an association between the probability that Oregon spotted frogs disappear from a site (local extinction) and any of the variables hypothesized to affect Oregon spotted frog occupancy. This 4-year study provides baseline data, but the 4-year period was too short to draw firm conclusions about current (2014) trends. Further study is essential to understand how habitat changes and management practices relate to the status and trends of this species.

Welcome to the 2013 Annual ARMI Update, which provides highlights and significant milestones of this innovative program. This was an especially notable year for ARMI with the release of a landmark publication “Trends in amphibian occupancy in the United States.” Our synthesis and scaling up of 9 years of monitoring data produced the first-ever estimate of how fast frogs, toads and salamanders in the United States are disappearing from their habitats. Our findings received international attention and rekindled the discussion about global amphibian declines. This was not the only topic we addressed this year, as ARMI’s total publication count rose to 460 papers representing our latest research findings on the effects of climate change, land use, diseases, pesticides, and management on amphibian populations.

Full text: https://armi.usgs.gov/docs/ARMI%202013%20Annual%20Update.pdf

Welcome to the 2012 ARMI Annual Update, which provides highlights and significant milestones of this innovative program. ARMI is uniquely qualified to provide research and monitoring results that are scalable from local to national levels and are useful to resource managers. ARMI has produced more than 420 peer-reviewed publications since its inception. Some of those publications are highlighted in this fact sheet. Please visit our website (http://armi.usgs.gov) for additional information on ARMI products, to find summaries of research topics, to search for ARMI activities in your area, or to obtain amphibian photographs. This year, we introduced a new feature on the ARMI website called “Trend Data” that provides occupancy and abundance estimates at the project level (http://armi.usgs.gov/projects/estimates_datasets.php). Data can be accessed in tabular format or plotted via an interactive map.

Full text: http://armi.usgs.gov/docs/ARMI%202012%20Annual%20Update.pdf

Welcome to the inaugural issue of ARMI’s Annual Update. This update provides highlights and significant milestones of this innovative program. ARMI is uniquely qualified to provide research and monitoring results that are scalable from local to national levels, and are useful to resource managers. ARMI has produced nearly 400 peer-reviewed publications, including 18 in 2011. Some of those publications are highlighted in this fact sheet. ARMI also has a new Website (http://armi.usgs.gov). You can now use it to explore an up-to-date list of ARMI products, to find summaries of research topics, to search for ARMI activities in your area, and to obtain amphibian photographs. ARMI’s annual meeting was organized by Walt Sadinski, Upper Midwest Environmental Science Center, and held in St Louis, Missouri. We met with local scientists and managers in herpetology and were given a tour of the herpetology collection at the St. Louis Zoo.

Full text: http://armi.usgs.gov/docs/ARMI%202011%20Annual%20Update.pdf (PDF*)

Wetlands in the remote mountains of the American West are the site of two massive ecological “experiments” spanning the 20th Century. In a kind of biological carpet-bombing following World War II, fish and wildlife managers introduced millions of predatory trout into fishless mountain ponds and lakes across the Western United States. The new top predators, which now occupy 95% of large mountain lakes, have truncated the habitat distributions of native frogs, salamanders, and wetland invertebrates to smaller, more ephemeral ponds where fish do not survive. Now a second “experiment” –anthropogenic climate change – threatens to push from the opposite direction; eliminating many ephemeral habitats and shortening wetland hydroperiods. Caught between climate-induced habitat loss and predation from introduced fish, native mountain lake fauna of the American West – especially amphibians– are at risk of being squeezed out. Targeted fish removals, guided by models of wetlands change, provide new strategies for restoring resilience.

Though a third of amphibian species worldwide are thought to be imperiled, existing assessments simply categorize extinction risk, providing little information on the rate of population losses. We conducted the first analysis of the rate of change in the probability that amphibians occupy ponds and other comparable habitat features across the United States. We found that overall occupancy by amphibians declined 3.7% annually from 2002 to 2011. Species that are Red-listed by the International Union for Conservation of Nature (IUCN) declined an average of 11.6% annually. All subsets of data examined had a declining trend including species in the IUCN Least Concern category. This analysis suggests that amphibian declines may be more widespread and severe than previously realized.

Despite the high profile of amphibian declines and the increasing threat of drought and frag- mentation to aquatic ecosystems, few studies have examined long-term rates of change for a single species across a large geographic area. We analyzed growth in annual egg-mass counts of the Columbia spotted frog (<i>Rana luteiventris</i>) across the northwestern United States, an area encompassing 3 genetic clades. On the basis of data collected by multiple partners from 98 water bodies between 1991 and 2011, we used state-space and linear-regression models to measure effects of patch characteristics, frequency of summer drought, and wetland restoration on population growth. Abundance increased in the 2 clades with greatest decline history, but declined where populations are consideredmost secure. Population growthwas negatively associated with temporary hydroperiods and landscape modification (measured by the human footprint index), but was similar in modified and natural water bodies. The effect of drought was mediated by the size of the water body: populations in large water bodies maintained positive growth despite drought, whereas drought magnified declines in small water bodies. Rapid growth in restored wetlands in areas of historical population declines provided strong evidence of successful management. Our results highlight the importance of maintaining large areas of habitat and underscore the greater vulnerability of small areas of habitat to environmental stochasticity. Similar long-term growth rates inmodified and natural water bodies and rapid, positive responses to restoration suggest pond construction and other forms of management can effectively increase population growth. These tools are likely to become increasingly important to mitigate effects of increased drought expected from global climate change.
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The Toiyable subpopulation of the Columbia spotted frog (Rana luteiventris) is located in central Nevada and is part of the Great Basin Distinct Population Segment (DPS). Columbia spotted frogs are of special concern as range-wide population declines have been documented and the species is a candidate for listing under the Endangered Species Act. Multiple state and federal agencies have cooperatively monitored this subpopulation over the last seven years, and will continue to do so in the near future. We restructured the database and estimated population parmeters using a Huggins Colosed Captures Robust Design Model. Derived estimates of population size did not show evidence of decline over the study years.

More than 25 years ago, scientists began to identify unexplained declines in amphibian populations around the world. Much has been learned since then, but amphibian declines have not abated and the interactions among the various threats to amphibians are not clear. Amphibian decline is a problem of local, national, and international scope that can affect ecosystem function, biodiversity, and commerce. This fact sheet provides a snapshot of the state of the amphibians and introduces examples to illustrate the range of issues in the United States.

This is the 2011 annual report for the Amphibian Research and Monitoring Initiative. It includes publication updates and a summary of amphibian monitoring trends.

Studies of the distribution of elusive forest wildlife have suffered from the confounding of true presence with the uncertainty of detection. Occupancy modeling, which incorporates probabilities of species detection conditional on presence, is an emerging approach for reducing observation bias. However, the current likelihood modeling framework is restrictive for handling unexplained sources of variation in the response that may occur when there are dependence structures such as smaller sampling units that are nested within larger sampling units. We used multilevel Bayesian occupancy modeling to handle dependence structures and partition sources of variation in occupancy of sites by terrestrial salamanders (family Plethodontidae) within and surrounding an earlier wildfire in western Oregon, USA. Comparison of model fit favored a spatial N-mixture model that accounted for variation in salamander abundance over models that were based on binary detection/non-detection data. Though catch per unit effort was higher in burned areas than unburned, there was strong support that this pattern was due to a higher probability of capture for individuals in burned plots. Within the burn the odds of capturing an individual given it was present were https://2.06 times the odds outside the burn, reflecting reduced complexity of ground cover in the burn. There was weak support that true occupancy was lower within the burned area. While the odds of occupancy in the burn were https://0.49 times the odds outside the burn among the five species, the magnitude of variation attributed to the burn was small in comparison to variation attributed to other landscape variables and to unexplained, spatially autocorrelated random variation. While ordinary occupancy models may separate the biological pattern of interest from variation in detection probability when all sources of variation are known, the addition of random effects structures for unexplained sources of variation in occupancy and detection probability may often more appropriately represent levels of uncertainty.

High variability in abundance, cryptic coloration, and small body size of newly metamorphosed anurans have limited demographic studies of this life history stage. We used line-transect distance sampling to estimate the abundance and spatial distribution of newly metamorphosed Western Toads (Anaxyrus boreas) in terrestrial habitat surrounding a montane lake in central Washington, USA. We completed 154 line-transect surveys from the commencement of metamorphosis (15 September, 2009) to the date of first snow accumulation in fall (1 October, 2009), and located 543 newly metamorphosed toads. After accounting for variable detection probability associated with the extent of barren habitats, estimates of total surface abundance ranged from a posterior median of 3880 (95% credible intervals from 2235 to 12600) in the first week of sampling to 12150 (5543, 51670) during the second week of sampling. Numbers of newly metamorphosed toads dropped quickly with increasing distance from the lakeshore in a pattern that differed over the three weeks of the study and contradicted our original hypotheses. Though we hypothesized that the spatial distribution of toads would initially be concentrated near the lake shore and then spread outward from the lake over time, we observed the opposite. Ninety-five percent of individuals occurred within 20, 16, and 15 m of shore during weeks one, two, and three respectively, probably reflecting continued emergence of newly metamorphosed toads from the lake and mortality or burrow use of dispersed individuals. Numbers of toads were highest near the inlet stream of the Lake. Distance sampling may provide a useful method for estimating the surface abundance of newly metamorphosed toads and relating their space use to landscape variables despite uncertain and variable probability of detection.

In the Pacific Northwest, amphibians inhabit forested streams ranging from barely a trickle up to larger rivers and inhabit streams as well as the surrounding forest. Many previous studies have found a negative effect of timber management on the abundance of stream amphibians, but results have been variable and region specific. These studies have generally used survey methods that do not account for differences in capture probability, which may be important if habitat condition alter capture probabilities. In addition, most of these studies have been retrospective comparisons of stands of different ages, and focus on stands that were harvested under older management practices. Over the last 30 years forest management practices have changed substantially, yet little work examines how modern forest management relates to the abundance or density of stream amphibians. We examined the influences of contemporary forest practices on Pacific giant salamanders as part of the Hinkle Creek paired watershed study. We used a mark-recapture analysis to estimate Pacific giant salamander Density at 100 1-m segments spread throughout the basin and then used extended linear models that accounted for correlation resulting from the repeated surveys at sites across years. Density was associated with substrate, but we found no evidence of an effect of harvest. While holding other factors constant, our top model indicated; 1) each 10 percent increase in proportion of the substrate that was small cobble or larger increased median density of Pacific giant salamanders https://1.06 times, 2) each 100 hectare increase in the area drained decreased median density of Pacific giant salamander https://0.93 times, and 3) increasing the fish density in the 40 m around a site by https://0.01 increased median salamander density https://1.02 times. Our mark-recapture analysis accounted for sampling inefficiencies at sites with captures, but sites with no captures retained densities of 0 in our extended linear analysis. At least some of these sites were likely occupied and we failed to capture individuals that were present. A Monte Carlo analysis suggested that our results were not sensitive to missing captures at some sites. We did not find evidence of a short term effect of timber harvest on the density of Pacific giant salamanders at Hinkle Creek.

Nielson et al. (2001) recommended that the genus Ascaphus be split into two species: tailed frogs (A. truei) and Montana tailed frogs (A. montanus). Their analysis was based on divergence of mitochondrial DNA and was consistent with previous allozyme work (Daugherty, 1979). The following account highlights references that are specific to the new species. Refer to the Ascaphus truei account for a complete review of the genus Ascaphus.