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1. Most applications of single-level occupancy models do not differentiate between availability and detectability, even though species availability is rarely equal to one. The availability process includes elements of species movement, behavior, and phenology, and availability can be estimated using multi-scale occupancy models. However, for the practical application of multi-scale occupancy models, it can be unclear what a robust sampling design looks like and what the statistical properties of the multi-scale and single-level occupancy models are when availability is less than one.

2. Using simulations, we explore the following common questions asked by ecologists during the design phase of a field study: (Q1) what is a robust sampling design for the multi-scale occupancy model when there are a priori expectations of parameter estimates?, (Q2) what is a robust sampling design when we have no expectations of parameter estimates?, and (Q3) can a single-level occupancy model with a random effects term adequately absorb the extra heterogeneity produced when availability is less than one and provide reliable estimates of occupancy probability?.

3. Our results show that there is a tradeoff between the number of sites and surveys needed to achieve a specified level of acceptable error for occupancy estimates using the multi-scale occupancy model. We also document that when species availability is low (< https://0.40 on the probability scale), then single-level occupancy models severely underestimate occupancy by as much as https://0.40 on the probability scale, produce overly precise estimates, and provide poor parameter coverage. This pattern was observed when a random effects term was and was not included in the single-level occupancy model, suggesting that adding a random-effects term does not adequately absorb the extra heterogeneity produced by the availability process. In contrast, when species availability was high (> 0.60), single-level occupancy models performed similarly to the multi-scale occupancy model.

4. As a companion, we provide an RShiny app that allows users to further explore our results and determine optimal designs across different sampling scenarios https://gdirenzo.shinyapps.io/multi-scale-occ/. Our results suggest that unaccounted for availability can lead to underestimating species distributions using single-level occupancy models, which can have large implications on ecological inference and predictions for practitioners, such as those working at the front lines of invasion ecology, disease emergence, and species conservation.

Protected areas like national parks are essential elements of conservation because they limit human influence on the landscape, which protects biodiversity and ecosystem function. The role of national parks in conservation, however, often goes far beyond limiting human influence. The U.S. National Park Service and its system of land units contribute substantively to conservation by providing protected lands where researchers can document trends in species distributions and abundances, examine characteristics important for generating these trends, and identify and implement conservation strategies to preserve biodiversity. We reviewed the contribution of U.S. national parks to amphibian research and conservation and highlight important challenges and findings in several key areas. First, U.S. national parks were instrumental in providing strong support that amphibian declines were real and unlikely to be simply a consequence of habitat loss. Second, research in U.S. national parks provided evidence against certain hypothesized causes of decline, like UV-B radiation, and evidence for others, such as introduced species and disease. However, describing declines and identifying causes contributes to conservation only if it leads to management; importantly, U.S. national parks have implemented many conservation strategies and evaluated their effectiveness in recovering robust amphibian populations. Among these, removal of invasive species, especially fishes; conservation translocations; and habitat creation and enhancement stand out as examples of successful conservation strategies with broad applicability. Successful management for amphibians is additionally complicated by competing mandates and stakeholder interests; for example, past emphasis on increasing visitor enjoyment by introducing fish to formerly fishless lakes had devastating consequences for many amphibians. Other potential conflicts with amphibian conservation include increasing development, increased risk of introductions of disease and exotic species with increased visitation, and road mortality. Decision science and leveraging partnerships have proven to be key components of effective conservation under conflicting mandates in national parks. As resource managers grapple with large-scale drivers that are outside local control, public-private partnerships and adaptive strategies are increasing in importance. U.S. national parks have played an important role in many aspects of identifying and ameliorating the amphibian decline crisis and will continue to be essential for the conservation of amphibians in the future.

The Shenandoah salamander (Plethodon shenandoah) is a federally endangered salamander whose distribution is restricted to three mountain peaks within Shenandoah National Park . During the ranking of vital signs monitoring priorities for SHEN, “Federal Threatened and Endangered Species” received the 2nd highest ranking for terrestrial vital signs because of ecological, management, and policy criteria. The following protocol describes the objectives and methods for monitoring the Shenandoah salamander. Because the range size and habitat occupancy are of principle interest, this protocol generates data suitable for estimating the annual proportion of occupied habitat across the species range. Objectives focus on describing the status and trends of the species distribution (i.e. spatial extent) and the proportion of the range that is occupied (i.e. density of occupied sites). To do so, monitoring sites in the core and the edge of the known range are surveyed for salamanders multiple times during both the spring and fall. The resulting data not only allow for an assessment of the status and trend of the species but also provide supporting data to assist in understanding causal drivers of population change.

Most translocation efforts are unsuccessful, often for unknown reasons. We assessed factors linked with population persistence for 25 years of translocations of the federally threatened Chiricahua Leopard Frog. Local features were paramount, including habitat, predators, and restoration history. Timing and life stages stocked affected persistence, but rearing environment did not. Two or more translocations produced an approximate 4-yr increase in predicted population persistence.

To inform responsible energy development, it is important to understand the ecological effects of contamination events. Wastewaters from oil and gas extraction often contain high concentrations of sodium chloride (NaCl) and heavy metals (e.g., strontium and vanadium), but studies of their influence on microbial communities are limited. We sampled water, sediment, and larval amphibian skin (four species) across a gradient of contamination (0.04–17500 mg/L Cl) in a large energy production area of North America. NaCl concentrations affected the similarity among microbiomes of water, sediment, and amphibian skin, but not the diversity or richness of water and skin microbiomes. Strontium concentrations were associated with lower diversity and richness of sediment microbial communities. Amphibian microbiomes were similar to those of water, but not sediment, and sediment microbiomes were similar to those of water. Species identity was the strongest predictor of amphibian microbiomes; frog microbiomes were similar but differed from that of the salamander, whose microbiome had the lowest richness and diversity. Understanding whether effects of wastewaters on microbial communities also influences their ecosystem function will be an important next step. Our study provides novel insight into associations among different wetland microbial communities and effects of wastewaters from energy production.

Dedicated long-term monitoring at appropriate spatial and temporal scales is necessary to develop effective conservation plans. Using an amphibian monitoring program for a network of U.S. National Parks, we compare monitoring program designs. Designs that reduce biases in parameter estimates are needed to guide conservation policy and management decisions in the face of broad scaled environmental challenges; the optimal design is sensitive to the specific objectives of a monitoring program.

We observed multiple toads in amplexus and depositing egg strings among the vegetation. The following night (2230 h on 28 May 2021) a convergence of over a dozen Western Tiger Salamander (Ambystoma mavortium) individuals was observed consuming A. boreas eggs that had been deposited 24-48 hours earlier

Northern Red-Bellied Cooters (Pseudemys rubriventris) have a disjunct distribution with a relictual population in southeastern Massachusetts and a larger range across the mid-Atlantic United States. The relictual population is currently listed with protections under the U.S. Endangered Species Act but the status of the population in the remainder of the species' range has not been assessed, and there is concern that it may be at risk of extinction without protection. The U.S. Fish and Wildlife Service requires scientific information of the species' status to inform conservation decisions. There is little empirical information available from P. rubriventris[I/] populations and, furthermore, the majority of what exists comes from the disjunct northern subpopulation. To fill data gaps in the species' life history and reduce geographic bias, we supplement available data from P. rubriventris[I/] with demographic rate estimates from other Pseudemys species to parameterize an age-structured population projection model. Our estimate of mean population growth rate was https://0.987 (0.92–1.04), indicating that P. rubriventris[I/] populations may be in decline. However, there was considerable uncertainty in our results, with 35% of projections resulting in stable or increasing populations. Additional uncertainty about parameter values, geographic variation, and current threats limit the assessment. We discuss the merits and limitations of our population projection modeling (PPM) approach where other analytical methods are precluded by lack of available data.