With projected decreases in biodiversity looming due to changing environmental conditions, it is important for conservation managers to have accurate predictions of species' distributions. Species distribution models (SDM) and mechanistic models that account for biophysical factors are important tools for predicting potential distributions for many species. Incorporating microclimate data into SDMs and mechanistic models has become an important step for developing biologically relevant models for organisms reliant on microclimatic regimes. However, there remains a need to compare and integrate the predictions from microclimate-derived SDMs and mechanistic models at fine spatio-temporal scales to improve predictive accuracy and quantify model uncertainty. We developed correlative SDMs and mechanistic models of potential resistance to surface activity for two salamanders using fine-resolution (3 m) microclimate data. Models were produced for the Great Smoky Mountains National Park, USA during the 2010, 2030, and 2050 time periods. We determined the spatio-temporal agreement between SDMs and mechanistic models to assess model uncertainty at varying spatial resolutions. We also modeled and assessed spatio-temporal variability within potential activity corridors. We found that agreement between fine-resolution microclimate SDMs and mechanistic models was generally poor and varied temporally, but model agreement increased and converged at varying coarser spatial resolutions. Furthermore, potential activity corridors spatio-temporally varied and demonstrated increased habitat fragmentation under future projections. The findings from this study highlight a contradiction in which we may need to model species distributions with microclimate data at finer, more biologically meaningful resolutions, but model agreement between correlative and mechanistic approaches may be weakened at these fine scales. Researchers may therefore need to strike a balance between increasing spatial resolution and study extent when integrating model approaches. Further quantifying model uncertainty and identifying alternative methods for integrating SDMs and mechanistic models will be an important step towards accurately predicting species distributions under changing environmental conditions.

Large-scale habitat loss and degradation have triggered a global biodiversity crisis with ecological-specialist species at increased risk of extinction. The Rattlesnake-Master Borer (Papaipema eryngii) is a small noctuid moth whose larvae feed exclusively on rattlesnake master (Eryngium yuccifolium), a native grassland plant ranging throughout the eastern United States. Widespread loss of grassland habitats has resulted in declines of P. eryngii and the species has been considered for listing under the U.S. Endangered Species Act. We analyzed the mitochondrial COI barcode sequences of 76 P. eryngii from across the species’ distribution to examine genetic diversity and structure, and to test for historical changes in population size. We found 26 haplotypes with high haplotype diversity and low nucleotide diversity. Small but significant amounts of genetic differentiation occurred between populations separated by the Mississippi River and among representation units, but > 90

Maintaining the genetic diversity of wildlife populations is important as reductions in genetic diversity can have negative consequences like reduced fitness caused by inbreeding depression or increased risk of extirpation. Anthropogenic disturbance can have long-lasting impacts on the genetic diversity of wildlife populations. Here, we evaluated how historic timber harvesting and settlement shape modern spatial patterns of genetic diversity in the narrow-range endemic red-cheeked salamander (Plethodon jordani) in the Great Smoky Mountains National Park (GSMNP). Using microsatellite genotypes from 549 individuals across 23 sites, we quantified genetic diversity, tested for isolation by distance, and assessed the relationship between genetic diversity and historic disturbance and elevation. We found spatial variation in genetic diversity and statistically significant isolation by distance. Sampling sites located near historically harvested or settled areas exhibited reduced genetic diversity, but this negative effect was moderated at high elevations where salamander densities are higher and microhabitats are more favorable. Additionally, historic disturbance was associated with reduced modern understory density, a habitat feature that positively influences salamander abundance. Our findings demonstrate that land-use legacies continue to shape both forest structure and the genetic diversity of a narrowly distributed amphibian nearly a century after large-scale timber harvest ceased. These results highlight the importance of incorporating historic landscape change into conservation planning, especially for high-elevation endemics whose long-term persistence may depend on maintaining genetic diversity and adaptive capacity.

The dependency on hibernacula for extended periods presents terrestrial reptiles with the challenge of locating thermally adequate hibernacula each winter. Defining the habitat characteristics of hibernacula is crucial for understanding the overwintering requirements and distributions of hibernacula-dependent reptiles, alongside identifying habitats which warrant special conservation concern. Our objectives were to identify the overwintering habitat characteristics of the imperiled timber rattlesnake Crotalus horridus in Illinois, USA, and to determine the distribution of likely hibernacula habitats throughout the state. Due to the initial sparsity of hibernacula records in Illinois, we adopted an iterative habitat suitability modeling process consisting of 3 distinct rounds of Maxent construction and revision. Each round was informed with updated information from model-guided surveys or by building rapport with in-state naturalists and researchers who knew of additional hibernacula locations. We created our final model using 36 hibernacula and identified slope angle (indicative of rock outcrops and shallow soils), topographical position index, forest patch area, and aspect (decomposed into 2 linearized variables: southness and eastness) as important drivers of C. horridus hibernacula habitat in Illinois. Together, the 5 variables and site surveys suggest the suitable overwintering habitat for C. horridus in Illinois is located on south- to southwest-facing outcrops on upper slopes and ridges of larger forest patches. Such habitat is distributed primarily in southern Illinois and throughout the Mississippi River and Illinois River border counties. Our study adds to the current understanding of the species’ overwintering requirements and provides a foundation for future ecological studies, management, and survey efforts throughout Illinois.

Amphibian populations, including those of lungless salamanders (Plethodontidae), are susceptible to population declines, especially considering current and predicted climate change. Like many organisms, plethodontid salamanders exhibit reproductive plasticity to maximize population growth in response to environmental conditions. A better understanding of the external causes of reproductive plasticity can provide more accurate population models through the explicit incorporation of such drivers. To this end, we sampled Southern Pygmy Salamanders (Desmognathus wrighti) along a 1345-m elevational gradient in Great Smoky Mountains National Park, USA, to determine the effects of body size and elevation on reproductive investment. Using Bayesian mixed effects models, we assessed whether body size, elevation, or a combination of these factors best explained the probability an individual was gravid, the number of ova in gravid females, and the number of testis lobes in mature males. We found that the interaction of body size and elevation best explained each reproductive measure. Larger females were generally more likely to be gravid, with annual reproduction in fully mature females at low to mid-elevations and roughly biennial reproduction at high elevations. We also found a positive relationship between body size and ova counts at low and mid-elevations, but despite a reduction in reproductive frequency at higher elevations, we found no effect of body size on ova count. In addition, the addition of testis lobes, which has commonly been used as a proxy of age in plethodontid salamanders, occurred at larger body sizes with increasing elevation. Our findings support previous work showing a relationship between body size and reproductive ecology in desmognathine salamanders while providing insight into the complexity of this relationship in the context of elevational clines. Reproductive ecology significantly influences population dynamics; thus, further refinement of these observed patterns and their underlying causes is necessary to advance plethodontid salamander population ecology.

A primary response to the Clean Water Act has been the development of numerous indices of biotic integrity (IBI) using various taxonomic groups to assess the condition of water bodies in the United States. The IBI is a frequently used approach for assessing the ecological integrity of streams; however, it is less commonly applied to wetland systems, despite the scientific and policy needs to assess wetland condition and develop ecological performance goals for wetland monitoring, creation, and restoration. Although a great deal of attention has been given to wetland acreage due to the "no net loss" policy over the past two decades, much less attention has been given to the ecological integrity of these same wetlands. To assess wetland health and function, regulatory agencies and land managers need clear performance standards that are based on the ecology of wetland organisms. To address this need, we sampled 242 wetlands distributed across 45 managed properties in Illinois, U. S.A. over three years (2012-2014) for adult and larval amphibians (12 samples per wetland). Amphibian assemblages make up critical ecological components of many wetland ecosystems and are considered useful bioindicators of environmental change because they are sensitive to various forms of environmental and habitat alteration. We developed an amphibian-based IBI (hereafter aIBI) for the assessment of seasonal wetlands and optimal sampling strategies to best quantify these wetlands (i.e., assessment of time and effort). The aIBI applied a conservation coefficient to all species captured; conservation coefficients were developed through a survey of amphibian experts (n = 16). We captured 25 amphibian species with an average of 7.11 amphibian species (range 1-13) per site. Using the species occurrence data collected from both dipnet and minnow trap surveys over 12 survey periods, we assessed the average percent error in the estimation of aIBIs and species richness. Our results show that a wetland can be accurately evaluated with amphibians in one field season, but that multiple samples during that field season will be necessary. We show that 4-5 surveys using multiple methods distributed throughout the spring and summer are required. This level of effort may be incongruent with existing definitions of 'rapid assessment', but it is the necessary level of effort needed to confidently and accurately evaluate wetlands using amphibians as an indicator taxon. Additionally, aIBI provides a more robust framework to assess wetland integrity compared to simple species richness or other similar methodologies.

Abstract Snakes are difficult to study due to their cryptic coloration, minimal movements, and use of inaccessible habitats. Although well‐timed surveys during a species' active season can result in higher detection rates and conserve survey resources (i.e., time and money), survey effort may not ensure the detection of rare and cryptic species. Thus, in such instances, a strategic species‐specific sampling design is needed. The Kirtland's snake (Clonophis kirtlandii) is a rare, cryptic species assumed to be experiencing range‐wide declines. Naturalists have noted the disappearance of Kirtland's snakes from various habitats since the early 1970s. The primary objective of our study was to determine detection of Kirtland's snakes and the environmental and temporal factors influencing detection. We calculated the effort needed to detect individuals at sites by estimating detection probabilities of 3 known Kirtland's snake populations in Illinois from 2019 to 2021. Based on 77 Kirtland's snake detections over 226 site visits (34.1%) across 3 study sites, we found that high cloud cover, moderate air temperature, and low relative humidity enhanced the detection probability of this species. The middle of May to the beginning of July was the best time to conduct surveys when detection rates were highest. As our results suggested, it is imperative to establish strategic monitoring programs maximizing conservation resources to document populations for conservation action and range shifts for species of conservation concern, such as Kirtland's snakes.

Population surveying and monitoring are important for identifying conservation needs and tracking trends in populations, communities, and ecosystems over time and laying the groundwork for conservation management and policy decisions. If species or populations go undetected because of inadequate effort or sampling design, protection and management cannot be properly provided. Due to the widespread loss of populations, the Eastern Massasauga (a rattlesnake) was recently listed as a federally threatened species in the United States; it is also listed as threatened in Canada. Given its current conservation status, there is considerable interest at state and federal levels in determining how to best survey for Eastern Massasaugas to aid in management decisions. Using a 16-year dataset, we examined the relationships among environmental, temporal, area, management, and search effort factors on the detection probability of Eastern Massasaugas. We found that four abiotic parameters (solar irradiance, shaded air temperature, three-day maximum air temperature, and humidity) and three search parameters (effort per researcher, search area, and search time of day) influenced detection of Eastern Massasaugas. As the current biodiversity crisis continues, the cost-effective use of resources and scientific expertise will continue to increase in importance. We hope our results stimulate similar analyses in other taxa, which will be critical for designing and implementing regional survey and monitoring programs.

Abstract Climate change is expected to systematically alter the distribution and population dynamics of species around the world. The effects are expected to be particularly strong at high latitudes and elevations, and for ectothermic species with small ranges and limited movement potential, such as salamanders in the southern Appalachian Mountains. In this study, we sought to establish baseline abundance estimates for plethodontid salamanders (family: Plethodontidae) over an elevational gradient in Great Smoky Mountains National Park. In addition to generating these baseline data for multiple species, we describe methods for surveying salamanders that allow for meaningful comparisons over time by separating observation and ecological processes generating the data. We found that Plethodon jordani had a mid‐elevation peak (1,500 m) in abundance and Desmognathus wrighti increased in abundance with elevation up to the highest areas of the park (2025 m), whereas Eurycea wilderae increased in abundance up to 1,600 m and then plateaued with increasing uncertainty. Litter depth, herbaceous ground cover, and proximity to stream were also important predictors of abundance (dependent upon species), whereas daily temperature, precipitation, ground cover, and humidity influenced detection rates. Our data provide some of the first minimally biased information for future studies to assess changes in the abundance and distribution of salamanders in this region. Understanding abundance patterns along with detailed baseline distributions will be critical for comparisons with future surveys to understand the population and community‐level effects of climate change on montane salamanders.

Wildlife are faced with numerous threats to survival, none more pressing than that of climate change. Understanding how species will respond behaviorally, physiologically, and demographically to a changing climate is a cornerstone of many contemporary ecological studies, especially for organisms, such as amphibians, whose persistence is closely tied to abiotic conditions. Activity is a useful parameter for understanding the effects of climate change because activity is directly linked to fitness as it dictates foraging times, energy budgets, and mating opportunities. However, activity can be challenging to measure directly, especially for secretive organisms like plethodontid salamanders, which only become surface active when conditions are cool and moist because of their anatomical and physiological restrictions. We estimated abiotic predictors of surface activity for the seven species of the Plethodon jordani complex. Five independent data sets collected from 2004 to 2017 were used to determine the parameters driving salamander surface activity in the present day, which were then used to predict potential activity changes over the next 80 yrs. Average active seasonal temperature and vapor pressure deficit were the strongest predictors of salamander surface activity and, without physiological or behavioral modifications, salamanders were predicted to exhibit a higher probability of surface activity during peak active season under future climate conditions. Temperatures during the active season likely do not exceed salamander thermal maxima to cause activity suppression and, until physiological limits are reached, future conditions may continue to increase activity. Our model is the first comprehensive field-based study to assess current and future surface activity probability. Our study provides insights into how a key behavior driving fitness may be affected by climate change.

Ichthyosporean parasites (order Dermocystida) can cause morbidity and mortality in amphibians, but their ecology and epidemiology remain understudied. We investigated the prevalence, gross and histologic appearance, and molecular phylogeny of a novel dermocystid in the state-endangered silvery salamander (Ambystoma platineum) and the co-occurring, non-threatened small-mouthed salamander (Ambystoma texanum) from Illinois. Silvery salamanders (N = 610) were sampled at six ephemeral wetlands from 2016 to 2018. Beginning in 2017, 1-3 mm raised, white skin nodules were identified in 24 silvery salamanders and two small-mouthed salamanders from five wetlands (prevalence = 0-11.1%). Skin biopsy histology (N = 4) was consistent with dermocystid sporangia, and necropsies (N = 3) identified infrequent hepatic sporangia. Parasitic 18S rRNA sequences (N = 5) from both salamander species were identical, and phylogenetic analysis revealed a close relationship to Dermotheca viridescens. Dermocystids were not identified in museum specimens from the same wetlands (N = 125) dating back to 1973. This is the first report of Dermotheca sp. affecting caudates in the Midwestern United States. Future research is needed to determine the effects of this pathogen on individual and population health, and to assess whether this organism poses a threat to the conservation of ambystomatid salamanders.

Ecologists are increasing the use of remote technologies in their research, as these methods are less labor intensive than traditional methods and oftentimes minimize the number of human errors. Camera traps can be used to remotely measure abundance and community composition and offer the potential to measure some phenotypic traits, such as body size. We designed a camera-trap setup that enabled us to capture images of both large and small animals and used our camera-trap design to investigate the community composition of mammals and birds and to estimate the biomass of mammals along two transects in a conservation reserve in Missouri. One transect ran from the edge of an agricultural field to an upland forest, and the other transect ran from the edge of a wetland to an upland forest. Over the 4.5-wk study, our cameras recorded 2,245 images that comprised 483 individuals of 16 species of mammals and birds. Coyotes Canis latrans and nine-banded armadillos Dasypus novemcinctus were unique to the riparian transect, as were several bird species. Fewer species used the forest immediately adjacent to the agricultural field, but more species used the forest immediately adjacent to the wetland. Biomass estimates from our camera-trap images were similar to those of published accounts. This is the first study to use camera traps to successfully estimate biomass. We showed that the value and utility of camera traps in wildlife studies and monitoring can be expanded by 1) using multiple cameras at different heights from the ground so as to capture different-sized animals and 2) obtaining phenotypic information of the captured animals.

Habitat use by California quail (Callipepla californica) was studied at the E. E. Wilson Wildlife Area in northwestern Oregon, a mesic extension of the range of this species, from 1974 to 1992. Abundance of quail on the area was related to plant succession. Dietary studies revealed that legumes-particularly deervetch (Lotus spp.), peavine (Lathyrusspp.), Scot's broom (Cytisusscoparius), and vetch (Viciaspp.)-oomposed 67% of the relative dry mass of the annual diet. California quail typically nested in shrub/grassland and roadside habitats with less grass and shrub cover and more bare ground than at random locations within those cover types. Blackberry (Rubus spp.) stands were used consistently for roosts and were the most frequently used escape cover. Abundance and productivity measures of California quail on treated sites-including disked areas, food plots, and wheat plantings revealed most birds (on a year-round basis) were found on disked areas and most chicks were produced on these sites. Fewest young hatched on food plots and wheat plantings and the latter had the lowest abundance of breeding adults. Most important food and cover plants responded positively to prescribed burning and disking but returned to pretreatment levels of abundance within 2-3 years. I concluded that the successful introduction of California quail into the Willamette Valley and abundance and productivity of these populations were related to the presence of certain early seral species of plants, particularly some exotic species, and plant succession

Ringed Salamanders are wetland-dependent amphibians that are regionally endemic to the Ozark Highlands and Ouachita Mountains. To assess the most important variables influencing breeding wetland use by Ringed Salamanders in east-central Missouri, we sampled a total of 38 wetlands during the fall 2010 breeding season. We found the presence of predatory fish was the most important variable determining whether Ringed Salamanders used a breeding wetland and that breeding wetlands were significantly associated with increased areas of continuous forest. These breeding habitat requirements can be used to aid in conservation efforts for this species as well as other fall-breeding ambystomatid salamanders.

The pathogenic chytrid fungus Batrachochytrium dendrobatidis (hereafter, Bd) is a causal agent in amphibian decline and extinction events. Sampling for Bd in the Midwestern United States has largely been opportunistic and haphazard, so little information exists on the true occurrence and prevalence of the disease. We repeatedly tested Cricket Frogs Acris blanchardi or A. crepitans at 54 wetlands in 2009 and 15 wetlands in 2011 on both public and military lands to estimate Bd occurrence and prevalence rates between different land-use types, sampling seasons (spring, summer, autumn) and sampling years. We found Bd occurred in 100% of wetlands we sampled in 2009 and 2011, and overall prevalence was 22.7% in 2009 and 40.5% in 2011. Batrachochytrium dendrobatidis prevalence in 2011 was significantly higher than in 2009 and was significantly higher during the spring season than in the summer or autumn. We also found Bd prevalence was not significantly different on military versus public-use sites and was most affected by the average 30-d maximum temperature prior to sampling. This study provides data on the occurrence and prevalence of Bd in the United States and fills an important gap in the Midwest, while also corroborating prior research findings of increased prevalence in the cooler spring season.

Mountain quail (Oreortyx pictus) are among the least studied of the North American quails. The prehistoric and early historic distributions of this bird are uncertain. In the Pacific Northwest, mountain quail were first recorded by Lewis and Clark in 1806 near the Columbia River adjacent to the Cascade Range in Oregon. Written evidence relating to the original distribution of mountain quail in this area indicated that the birds were found from the Oregon Coast Range to the Cascades along the Columbia River and southward. Translocations of birds into this region began in 1860 and continued for several decades, which further confused the historic status. Eventually, mountain quail were distributed from southern British Columbia throughout Washington and into western Idaho and eastern Oregon by the early 20th century. Archeological evidence revealed it is possible that mountain quail existed in west-central Idaho, likely as refugia populations, 700 to 1000 years ago. Populations in Idaho and the interior Columbia River Basin have declined substantially during the past several decades. Similar declines have not been observed in the Pacific Northwest (western Oregon) or in the humid coastal region of western California.

Animals must navigate a complex mosaic of habitat types, both natural and artificial. As artificial habitats (e.g., agricultural fields) become increasingly abundant in many landscapes, species will be affected differently, depending on their habitat preferences. We investigated the diversity, richness, abundance, and biomass of mammals and birds with remote camera traps that optimized the capture of both large and small animals. Camera traps allowed us to capture natural rates of mammals and birds, which is difficult to obtain using human observers who can affect the behavior of animals and are limited in their spatio-temporal scope and ability to assess nocturnal communities. Our camera trap arrays were established along two transects in a local conservation reserve; one transect ran from an agricultural field to an upland forest and another from a wetland to an upland forest. Over the 6-week study our cameras recorded 2,245 images, within which we observed 483 individuals comprising 16 species of mammals and birds. Our data showed that species composition and abundances were only marginally different between the two transects, with species common to both transects not exhibiting any statistical difference in abundances. Coyotes and armadillos were unique to the riparian transect, and many more bird species were present along the riparian transect than the agricultural transect. Diversity, richness, and total community biomass did not differ significantly between the two transects nor along each transect but there were non-significant trends in predicted directions. Our results revealed that fewer species use the forest immediately adjacent to the agricultural field, but more species use the wetland and the forest immediately adjacent to the wetland. Our results corroborate other studies revealing that certain species are more common in forested areas but also that some species thought to prefer forested areas may actually be more habitat generalists than previously thought.

Mountain quail (Oreortyx pictus) have declined in much of the Intermountain Region of the western United States. Many areas that once supported these birds now seemingly lack necessary food and cover, especially in critical riparian zones. Additionally, mountain quail appear to need periodic disturbance (fire, moderate grazing, etc.) to provide adequate forage and nesting areas. If mountain quail do not readily occupy suitable habitats, either because of restricted movements or because of habitat discontinuities, it may be necessary to stock birds in order to restore populations. In September 1995, we began a restoration program with the objective of reintroducing mountain quail into former ranges in eastern Oregon and Washington. In the winter of 1996--1997, we released 17 radio-marked birds into a drainage in Hell's Canyon as a pilot study to determine habitat use, survival estimates, and movement patterns. An additional 40 radio-marked birds were released during spring 1998 to determine habitat use, nesting success, and brood survival.