Recently, artificial shelters have been proposed as a novel tool to monitor Hellbenders (Cryptobranchus alleganiensis) and other cryptobranchid salamanders. Factors that influence artificial shelter use by Hellbenders have not been identified, but are important for maximizing the utility of these shelters as monitoring tools. To identify these factors, in 2013–2018 we deployed 438 artificial shelters across 10 stream reaches inhabited by Hellbenders, within three rivers in the upper Tennessee River Basin. We hypothesized that occupancy and nesting would depend on shelter placement, and would be greatest in reaches with relatively high densities of adult/subadult Hellbenders (i.e., >1.5 individuals per 100 m²). We placed shelters in locations representing a range of instream conditions, but avoided microhabitats that were not suitable for Hellbenders. We monitored shelter occupancy by Hellbenders every 2–8 wk, and surveyed shelters for nests every 2–5 d during their breeding season. We quantified densities of adult/subadult Hellbenders and 10 habitat variables across multiple spatial scales. Hellbenders occupied 46% of artificial shelters, and nested in 17% of artificial shelters that were in place for at least one breeding season. Hellbenders were most likely to occupy and nest in shelters placed in portions of those reaches that were ≥50 cm deep with high densities of adult/subadult individuals. Among the variables we considered, population density was the most important factor influencing shelter occupancy by Hellbenders. Shelter nesting was most influenced by water depth, but also by population density and time since shelter installation. Both occupancy and nesting in shelters increased for 2–3 yr following shelter deployment. Our results provide evidence that artificial shelters constitute efficient tools in some streams for monitoring the occurrence and reproduction of Hellbenders.

Mudpuppies (Necturus maculosus) are secretive, fully aquatic salamanders with a range that spans much of the eastern United States and Canada including the Great Lakes region. Although this species was once abundant, there have been widespread declines due to habitat loss and modification, pollution, lampricide use, and overcollection. We compared environmental DNA (eDNA) and trapping surveys conducted from 2014 to 2016 to determine Mudpuppy occupancy along the St. Clair-Detroit River System, where this indicator species could be a gauge for success of ongoing restoration. Mudpuppy eDNA was detected at all sites with positive trapping records, as well as one site where individuals have not been trapped previously. Sites with shoreline restoration had the highest occupancy estimates, whereas deep-water restoration did not affect Mudpuppy occupancy. Additionally, eDNA surveys resulted in higher detection probability than setline and minnow trap survey methods, illustrating the benefit of using eDNA to detect secretive species. This study demonstrates the success of restoration efforts in increasing the occupancy of an indicator species and can be used as a template for other restoration initiatives.

In population studies, individual physiological metrics can reveal important aspects of ecology and act as indicators of overall population health. Body condition is frequently used as a metric of physiological status and commonly quantified as some function of mass relative to structural size. In this study, we examined the natural variation in body condition of two central Texas spelerpines (Eurycea sosorum and E. tonkawae: Plethodontidae) to understand their nutritional status as a function of environmental variability and reproductive condition. Rather than using a mass-based metric to generate a body condition index (BCI), we used residuals from a linear regression of tail width vs. body length measured from subject photographs taken from the dorsal perspective. Overall, mean BCI for both species was lowest in the winter and generally higher in spring and summer. Streamflow had a small positive effect on E. tonkawae BCI and a negative effect on E. sosorum BCI. Gravid individuals for both species had lower BCI during autumn and winter (when the proportion of gravid individuals was the greatest) than nongravid individuals. By contrast, the few gravid E. sosorum we observed in summer had higher BCI than nongravid individuals. Our results provide important baseline information on the ecology of these federally protected salamanders and demonstrate the utility of a BCI based on width instead of mass.

Reintroductions are an important recovery tool for endangered species but have had varying success. We used demographic data to evaluate the use of reintroductions for the recovery of the federally endangered Sierra Nevada Yellow-legged Frog (Rana sierrae) in stream populations in its northern range where the species is particularly at risk. We conducted a capture–mark–recapture study from 2016–2018 in four diverse streams. One of the streams contained a high abundance of frogs that allowed us to investigate demography in a relatively healthy population. In another of the streams, we tested a reintroduction using captive-reared frogs. We used robust design Huggins and Pradel models to estimate abundance, apparent overwinter survival, recruitment, longevity, and sex ratios. Annual abundance estimates were small, with ≤52 wild adult frogs at three streams and few tadpoles or subadults seen in any of the streams. The oldest frog in our streams was at least 13 yr. Estimates of apparent survival rates of wild adults ranged from 0.55 ± 0.05 standard error (SE) to 0.90 ± 0.05 SE, and estimates of annual recruitment ranged from 0.02 ± 0.11 SE to 0.26 ± 0.03 SE per site. High survival rates leading to long-lived adults may facilitate persistence of these stream populations, whereas low recruitment may limit population growth and recovery. The two largest populations were in intermittent streams, which may reflect their roles as a refuge from fishes. At least 52% of captive-reared frogs survived their first summer after release and at least 36% survived their first winter. Apparent overwinter survival of captive-reared frogs was lower than for wild frogs, ranging from 0.29 ± 0.13 SE to 0.56 ± 0.14 SE. Because of the apparent low survival of wild eggs, tadpoles, and subadults, releasing adults as was done in this study, rather than younger life stages, may be more successful. Our results offer promise for the use of reintroductions to augment depleted populations and suggest that further research on factors affecting recruitment and survival of younger life stages is needed.

Climate change has caused substantial shifts in the phenology for many species across a broad array of life-history events. Ectotherms are no exception; recent studies have discovered strong climate associations with nesting phenology for many turtle species. We studied phenology for the International Union for Conservation of Nature (IUCN)-endangered Blanding's Turtle (Emydoidea blandingii) across 16 yr in Wisconsin, USA to assess the potential for climate-associated shifts in this species. We hypothesized that, as with other freshwater turtles, Blanding's Turtle nesting phenology should be a function of climate. Furthermore, phenological shifts should be relatively consistent among nest sites within our study area given the scale of climate effects. Although nesting phenology did not advance significantly through time, nesting phenology was linked to March temperatures and was earlier in warmer years. Effects of March temperatures on nesting phenology were similar among nesting sites. Although no temporal trends in nesting phenology were evident, the strength and spatial uniformity of climate associations with nesting behavior documented by our study indicate that phenological shifts are likely, highlighting an additional form of climate vulnerability not previously recognized for this species.

Across the globe, conflicting priorities exist in how land and resources are managed. In the American West, conflicts are common on public lands with historical mandates for multiple uses. We explored the impacts of multiple uses of land in a case study of Agassiz's Desert Tortoises (Gopherus agassizii), a federally threatened species, in the western Sonoran Desert. The tortoise has declined for many reasons, most of which relate to management of land and habitat. Frequently cited causes are livestock grazing, roads, vehicle-oriented recreation, predators, and disease. In spring of 2009, we conducted a survey to evaluate relationships between desert tortoises, vegetation associations, topography, predators, and anthropogenic uses. We sampled a 93-km² area with 200 independent 1-ha plots. Density (± SE) of adult tortoises was low, 2.0 ± 1.0/km², and the annualized death rate for adults during the 4 yr preceding the survey was high, 13.1%/yr. We observed tortoise sign, most of which was recent, on 22% of the 200 plots, primarily in the southwestern part of the study area. More tortoise sign occurred on plots with Brittlebush (Encelia spp.) vegetation at higher elevations. Most plots (91.0%) had ≥1 human-related impacts: feral burro scat (Equus asinus; 84.0%), recent vehicle tracks and trails (34.0%), trash (28.0%), burro trails and wallows (26.5%), and old vehicle tracks (24.0%). We used a multimodel approach to model presence of tortoise sign on the basis of 12 predictor variables, and calculated model-averaged predictions for the probability of tortoise presence. Importance values revealed two apparent top drivers: feral burros and vegetation association. This is the first study to identify a negative association between presence of desert tortoises and feral burros.

Agriculture poses a threat upon wildlife worldwide and particularly to reptiles. However, the effects of many crop types on reptile diversity remain unknown. In this field study, we examined the local effects of two understudied common crop types in Mediterranean regions, intensively cultivated vineyards and intensified-traditional olive plantations, on reptile diversity patterns. We compared measurements of diversity among an array of study plots representing each crop as well as plots in adjacent patches of natural habitat. We developed a new index, the Average Specialization Index, in order to compare the degree of habitat-specialization of the species in the different habitats. Among the habitat types examined, the natural patches were the most structurally heterogeneous and contained the greatest species richness and diversity. In contrast, the intensive vineyards were structurally homogeneous and were uninhabitable areas for reptiles. The more-traditionally cultivated olive plantations were intermediately heterogeneous and provided a unique habitat occupied by a community with a high proportion of reptile species considered to be habitat specialists. Despite showing high abundance and eveness, the reptile community within the olive plantations still contained a lower species richness and diversity compared to natural patches. In light of our results, we recommend implementing a more wildlife-friendly management strategy in landscapes converted to agricultural cultivation.

The Eurycea bislineata complex (“two-lined salamanders”) of eastern North America contains six described species, of which three have very similar morphologies and relatively broad geographic distributions, and three have more divergent morphologies with narrow geographic distributions. Recent molecular phylogenetic analyses found that four of the six species in the complex contain deep genetic structure, and that two of the species (E. cirrigera and E. wilderae) are paraphyletic in mitochondrial and nuclear DNA, inferring that current taxonomy does not reflect actual species boundaries in the complex. The member of this complex in the Sandhills physiographic region of south-central North Carolina, USA, is notable for its distinctive coloration and ecology, and a study on allozymic variation published over 30 years ago demonstrated that it is genetically distinct but clustered within the paraphyletic E. cirrigera. This study investigates the taxonomic status of the Sandhills population using morphology, mitochondrial DNA, and a 21-locus nuclear DNA data set to test if the Sandhills taxon represents a local ecomorph that is conspecific with adjacent populations of E. cirrigera, or if it represents a divergent evolutionary lineage that warrants taxonomic recognition. Mitochondrial and nuclear DNA revealed that the Sandhills taxon is genetically distinct and phylogenetically unrelated to adjacent populations of E. cirrigera. Principal components analysis of 316 adult specimens of the Sandhills taxon and the three morphologically similar species in the complex found considerable overlap among these taxa, but pairwise comparisons of heavily loading morphological characters showed that the Sandhills taxon usually has a shorter body, shorter tail, and narrower head. Based on these corroborated lines of evidence, the hypothesis that the Sandhills taxon represents only a local ecomorph is rejected and it is described as a new species. Clarification of the extent of its geographic range (including its possible presence in South Carolina), differentiation of larvae from other members of the complex, and verification of hypothesized narrow zones of hybridization with E. cirrigera at the peripheries of its geographic range are needed. The description of the Sandhills taxon brings the number of endemic salamander species in North Carolina to seven. Integrative taxonomic revisions of the E. bislineata complex, particularly E. cirrigera and E. wilderae, are needed to estimate species diversity and distributions of these salamanders more accurately.