Conservation practitioners must contend with an increasing array of threats that affect biodiversity. Citizen scientists can provide timely and expansive information for addressing these threats across large scales, but their data may contain sampling biases. We used randomization procedures to account for possible sampling biases in opportunistically reported citizen science data to identify species' sensitivities to human land use. We analyzed 21,044 records of 143 native reptile and amphibian species reported to the Carolina Herp Atlas from North Carolina and South Carolina between 1 January 1990 and 12 July 2014. Sensitive species significantly associated with natural landscapes were 3.4 times more likely to be legally protected or treated as of conservation concern by state resource agencies than less sensitive species significantly associated with human-dominated landscapes. Many of the species significantly associated with natural landscapes occurred primarily in habitats that had been nearly eradicated or otherwise altered in the Carolinas, including isolated wetlands, longleaf pine savannas, and Appalachian forests. Rare species with few reports were more likely to be associated with natural landscapes and 3.2 times more likely to be legally protected or treated as of conservation concern than species with at least 20 reported occurrences. Our results suggest that opportunistically reported citizen science data can be used to identify sensitive species and that species currently restricted primarily to natural landscapes are likely at greatest risk of decline from future losses of natural habitat. Our approach demonstrates the usefulness of citizen science data in prioritizing conservation and in helping practitioners address species declines and extinctions at large extents.

Animal body sizes in urban areas often differ from nearby rural areas, which may impact population fitness and dynamics. We examined the effects of urbanization on larval body sizes of two species of salamanders, the two-lined salamander (Eurycea cirrigera) and the northern dusky salamander (Desmognathus fuscus). Specifically, we utilized a before-after control-impact (BACI) study design which allowed for the assessment of differences in larval body size between multiple control and impacted sites over a 5 year period. We found a decrease in larval body size in both species at the impacted sites compared to control sites in the first year after urbanization, followed by generally larger body sizes in urban sites compared to control sites in years 3–5, and significantly so in year 4. Using generalized linear models, we found support that larger body sizes post impact in urbanized streams may be due to warmer stream water temperature and decreased abundance of larvae. Both E. cirrigera and D. fuscus are well known for their ability to persist in urbanized streams; our data suggest that despite overall lower abundances in urban streams, persistence may be due to increases in larval body size and, potentially, post-metamorphic benefits.

1. Diamondback terrapins (Malaclemys terrapin) have experienced declines throughout their range, and accidental mortality in crab pots is a significant conservation concern. To minimize the risk of terrapins entering crab pots, researchers have suggested the use of bycatch reduction devices (BRDs) to reduce the size of crab pot openings and thereby exclude terrapins from entering crab pots. Despite these recommendations, few studies have observed terrapin interactions with BRDs and effectively evaluated the efficacy of these devices at preventing the entry of terrapins into pots.2. The objective of this study was to determine the effect of BRD presence and orientation on terrapin behaviour around crab pots and overall terrapin capture rates.3. In a controlled laboratory setting, terrapins investigated crab pots more frequently when crab pots were baited with fish versus chicken. Terrapins were captured more frequently when BRDs were not installed. The presence of the BRDs also increased the length of time necessary for a terrapin to enter a crab pot and decreased the proportion of entries relative to the number of investigations. Vertically-oriented BRDs were more effective than horizontally-oriented BRDs at reducing terrapin captures.4. To prevent the continued decline of terrapin populations due to crab fisheries, it is recommended that crabbers avoid the use of fish as bait in crab pots to reduce the attractiveness of pots to terrapins and fit all crab pots with vertically-oriented BRDs to reduce terrapin entrapment. Copyright (C) 2015 John Wiley & Sons, Ltd.

Spotted salamanders (Ambystoma maculatum) are pond-breeding amphibians that disperse into terrestrial habitat from natal wetlands after undergoing metamorphosis, relying on small-mammal burrows and coarse woody debris for refugia. The effect of conspecifics on burrow use in juvenile salamanders is poorly understood. Determining how the presence of conspecifics influences the settlement decisions of juvenile salamanders can increase our understanding of amphibian dispersal and our ability to predict population dynamics. We conducted behavioral laboratory trials using 58 recently metamorphosed salamanders to examine how salamanders selected burrows in the presence of conspecifics. Salamanders were more likely to settle in a burrow that was occupied by a conspecific versus an unoccupied burrow. Our results indicate that juvenile salamanders may show conspecific attraction and/or trailing behavior during the dispersal phase.

Because resources are finite, female animals face trade-offs between the size and number of offspring they are able to produce during a single reproductive event. Optimal egg size (OES) theory predicts that any increase in resources allocated to reproduction should increase clutch size with minimal effects on egg size. Variations of OES predict that egg size should be optimized, although not necessarily constant across a population, because optimality is contingent on maternal phenotypes, such as body size and morphology, and recent environmental conditions. We examined the relationships among body size variables (pelvic aperture width, caudal gap height, and plastron length), clutch size, and egg width of diamondback terrapins from separate but proximate populations at Kiawah Island and Edisto Island, South Carolina. We found that terrapins do not meet some of the predictions of OES theory. Both populations exhibited greater variation in egg size among clutches than within, suggesting an absence of optimization except as it may relate to phenotype/habitat matching. We found that egg size appeared to be constrained by more than just pelvic aperture width in Kiawah terrapins but not in the Edisto population. Terrapins at Edisto appeared to exhibit osteokinesis in the caudal region of their shells, which may aid in the oviposition of large eggs.

Relationships between behavioral regulation, environmental temperatures, and physiological tolerance are critical to conservation policy; however, these relationships may not be consistent among sister taxa. A species geographic range is influenced by various factors including physiological tolerance to temperature change. In this study, we investigated the effects of temperature variation on thermal preference and standard metabolic rates (SMR) of two species of larval salamanders, Eurycea cirrigera (Southern Two-Lined Salamander) and Eurycea wilderae (Blue Ridge Two-Lined Salamander). These species share similar life histories, but E. cirrigera is broadly distributed and E. wilderae occupies a smaller range. We measured SMR using volume of oxygen consumption during closed-circuit respirometery trials conducted at 5 degrees C increments between 5 degrees C and 25 degrees C. Standard metabolic rates were influenced by temperature, with a range of temperature-independent SMRs observed at those temperatures above each species laboratory-determined thermal preference. Concordant with their thermal preference (15.70 degrees C) and more-narrow geographic range, E. wilderae exhibited a smaller scope of temperatures at which SMR was temperature-independent, relative to E. cirrigera, and metabolic rates were depressed at 25 degrees C. Therefore, preferred thermal temperatures corresponded with physiological maxima and environmental temperatures in each species. Our results support the importance of behavioral thermoregulation in maintaining optimal physiological function. Further, these findings indicate that the physiological specialization that occurs in species of narrow geographic ranges may preclude favorable responses to changing environmental temperatures caused by land-cover changes, including loss of riparian forest in the Eastern United States.

Individual size is an important determinant of the outcomes of inter- and intraspecific interactions. Different-sized members of a guild might represent prey, competitors, or predators. Although direct predation rates might be low, trait-mediated indirect effects of predators on prey can yield altered activity, microhabitat use, survival, and growth. If individuals respond to all sizes of a predator regardless of the predation threat, antipredator behaviors might incur costs for prey as they forgo foraging opportunities or experience predation by other predators. Accurate assessment of predation risk would minimize costs resulting from antipredator behavior. We evaluated the ability of larval salamanders to assess predation risk and alter their habitat selection in response to intraguild competitors and predators. Specifically, we assessed behavioral responses to the presence of a conspecific, a similarly sized heterospecific, and a small or large individual of a predatory species. We predicted that larval salamanders would select habitat differently in the presence of a large predatory heterospecific, but not in the presence of similarly sized heterospecifics or conspecifics. The focal species occupied habitat 29 +/- 0.02% farther from a large heterospecific predator than from small heterospecifics, even if the heterospecifics were smaller individuals of the predatory species. The focal species also exhibited escape behaviors only in the presence of the large members of the predatory species. These data indicate that salamander larvae can assess size-specific predation threats, minimizing predation risk through use of antipredator behaviors.

Studies on the spatial ecology of invasive species provide critical information for conservation managers such as habitat preferences and identification of native species at risk of predation. To understand the spatial ecology of non-native Burmese pythons (Python molurus bivittatus), now well-established in Everglades National Park and much of South Florida USA, we radio-tracked 19 wild-caught adult pythons, 16 with VHF tags during 2006 through 2009 and 3 by GPS tags between 2010 and 2011. Our goal was to identify individual core-use areas and quantify home ranges, as well as to explore correlations of python movements with environmental parameters such as the presence of surface water.

The following is the first in the JNAH series in which we address a variety of topics on herpetology based on essays from our upcoming book “How to Be a Herpetologist,”. We will also answer frequently asked questions we and other professional herpetologists receive from students, colleagues, and the general public about herpetology as a career or an avocation.

Members of the Crotalus triseriatus species group of montane rattlesnakes are widely distributed across the highlands of Mexico and southwestern USA. Although five species are currently recognized within the group, species limits remain to be tested. Genetic studies suggest that species may be paraphyletic and that at least one cryptic species may be present. We generate 3,346 base pairs of DNA sequence data from seven nuclear loci to test competing models of species delimitation in the C. triseriatus group using Bayes factor delimitation. We also examine museum specimens from the Trans-Mexican Volcanic Belt for evidence of cryptic species. We find strong support for a nine-species model and genetic and morphological evidence for recognizing two new species within the group, which we formally describe here. Our results suggest that the current taxonomy of the C. triseriatus species group does not reflect evolutionary history. We suggest several conservative taxonomic changes to the group, but future studies are needed to better clarify relationships among species and examine genetic patterns and structure within wide-ranging lineages.

Despite the functional importance of isolated wetlands as supporters and sources of diverse assemblages of amphibians and reptiles, they lack federal protection and local protection is often insufficient to halt their destruction. A key step in guiding informed policy towards isolated wetlands is to understand their economic value. This study combines a year of intensive amphibian surveys within a wetland with the assignment of values to each of the captured species based upon their reported commercial values. The 392,605 amphibians comprising 17 species captured at this wetland in 1 y were valued at $ 3,605,848 (U. S. dollars). Juvenile amphibians produced in the wetland in a single year accounted for the 95% of the reported value ($ 3,413,821). This value far exceeds the value of other natural habitats evaluated with similar methods and exceeds by two orders of magnitude the value of this land had it been converted to agriculture. Although this study does not advocate amphibian harvest as an economic use for wetlands, it does highlight the value, diversity, and abundance of amphibians inhabiting these small, isolated, and often unprotected wetlands and provides a foundation for future research, management, mitigation, and policy.

Navigational ability is a critical component of an animal's spatial ecology and may influence the invasive potential of species. Burmese pythons (Python molurus bivittatus) are apex predators invasive to South Florida. We tracked the movements of 12 adult Burmese pythons in Everglades National Park, six of which were translocated 21–36 km from their capture locations. Translocated snakes oriented movement homeward relative to the capture location, and five of six snakes returned to within 5 km of the original capture location. Translocated snakes moved straighter and faster than control snakes and displayed movement path structure indicative of oriented movement. This study provides evidence that Burmese pythons have navigational map and compass senses and has implications for predictions of spatial spread and impacts as well as our understanding of reptile cognitive abilities.

Context Both manual call surveys (MCS) and visual encounter surveys (VES) are popular methods used to monitor anuran populations. Recent statistical developments, specifically the development of occupancy models that permit the use of data from various survey methods to assess method-specific detection probabilities, provide a rigorous framework for evaluating the effectiveness of field methods. Aim To compare species-specific detection probabilities generated by MCS and VES and to evaluate the effectiveness of these methods throughout the activity season of several riparian-zone anuran species. Methods During 2010 and 2011, we sampled 21 sites along the Broad and Pacolet Rivers, in South Carolina, USA, using MCS and VES. Anuran species were surveyed across three seasons (fall, spring and summer) each year. Key results For six species, MCS resulted in a higher mean probability of detection, whereas VES resulted in a higher mean probability of detection for four species. In addition, survey date was an important influence on detection probability of most anurans when using MCS, but largely unimportant when employing VES. Conclusions Our findings indicated that VES are as effective as MCS for detecting some species of anurans, and for others, VES represent a more effective method. Furthermore, when using VES outside the breeding window, some anurans can be reliably detected, and in some cases, detected more easily than by using MCS. Implications We suggest that VES is a complimentary technique to MCS and a potentially important tool for population monitoring of anurans. VES can provide more flexibility for anuran researchers, as robust estimates of detection and occupancy can be obtained outside a narrow breeding window.