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The Journal of Herpetology (JH), which reached its 50th volume in 2016, had an unusual start. Its predecessor publication was founded in 1958 by high school students as the Journal of The Ohio Herpetological Society (JOHS), which was sponsored by an amateur organization. The scope of the journal as well as that of the society soon became broader than Ohio or even North America. In 1967 OHS transformed into the Society for the Study of Amphibians and Reptiles (SSAR), which today is the largest professional herpetological society in the world. The journal was re-named Journal of Herpetology in 1968 and the volumes numbered again from 1. The journal, like SSAR, grew rapidly in size and professionalism. In 2009, JH was selected as one of the “100 most influential journals in biology and medicine worldwide over the last 100 years.” Originally, taxonomy–systematics (37%), ecology (20%), behavior (16%), physiology (8%), and genetics (4%) predominated as topics in JH; today, ecology (28%), conservation (19%), behavior (16%), taxonomy–systematics (13%), and physiology (9%) predominate. The JH is now the most-popular scientific journal in the world for biologists to publish on amphibians and reptiles. In this historical essay, I discuss major events in the development of the journal and list (in an Appendix) the editorial teams that collectively have helped shape JH.
El “Journal of Herpetology” (JH), el cual llegó a su volumen número 50 en 2016, tuvo un inicio poco usual. Su publicación predecesora fue fundada en 1958 por estudiantes de educación media superior, los cuales la nombraron el “Journal of The Ohio Herpetological Society” (JOHS), una organización amateur. El alcance de la revista así como el de la sociedad muy pronto se expandieron más allá de los límites de Ohio e incluso de Norteamérica. En 1967 la OHS se transformó en la “Society for the Study of Amphibians and Reptiles” (SSAR), que actualmente es la organización herpetológica profesional más grande del mundo. La revista se rebautizó “Journal of Herpetology,” en 1968 y los volúmenes se numeraron nuevamente desde el 1. La revista así como la SSAR crecieron rápidamente en tamaño y profesionalismo. En 2009, el JH fue seleccionado como una de “las 100 revistas más influyentes en biología y medicina a nivel mundial en los últimos 100 años.” Originalmente, la taxonomía/sistemática (37%), ecología (20%), comportamiento (16%), fisiología (8%) y genética (4%) fueron en orden de importancia los temas predominantes en el JH; mientras que ahora lo son: ecología (28%), conservación (19%), comportamiento (16%), taxonomía/sistemática (13%) y fisiología (9%). El JH es actualmente la revista científica más popular en el mundo entre los biólogos que publican sobre anfibios y reptiles. Los eventos más importantes en el desarrollo de la revista se discuten y se da una lista de los cuerpos editoriales en un Apéndice.
Where endangered species occur, recommendations call for conservation education programs that engage local educators; however, few studies have measured the effectiveness of implemented programs. We conducted a multipartner educator workshop for the endangered Houston Toad, Anaxyrus houstonensis, as one local example illustrating the broader issue of globally declining amphibians. We measured the effect of the workshop on participants' (n = 50) awareness/knowledge, values, beliefs, emotions, and intent to take action. We observed significant increases in awareness/knowledge and values regarding general amphibian declines and the focal species. The workshop significantly increased participants' belief that they had necessary resources to teach about the Houston Toad. Ninety-nine percent of participants agreed that they cared more about wild toads after meeting live ambassador toads. Postworkshop, we observed a 33% increase in use of amphibians or Houston Toads in participant learning settings. We recommend that educator workshops include biologist–educator teams, identify and address incentives and barriers to action, develop ecological knowledge, and incorporate experiential programming focused on native species and habitats.
Snakes, as ectotherms, rely heavily on environmental temperature to drive physiological processes. Activity in terrestrial snakes is influenced heavily by environmental temperature, but climatic, temporal, and ecological factors play a role as well. Understanding when and under what conditions a species is most likely to be active on the surface can be important when dealing with a cryptic species and a species that occurs at low densities. Surface activity, body temperature (Tb), and microclimatic data were collected during a study of 17 Heterodon platirhinos in an early-successional sand-dune ecosystem from 2009 to 2011 using temperature-sensitive radiotransmitters. Mean Tb (27.9°C, SE = 0.24) and Tb range (5.5–39.5°C) were similar to those reported in other studies of H. platirhinos. Females were generally more active than males, except in September when males may be searching for mates. Mixed-effects logistic regression was used to assess the relationship between snake surface activity and selected microclimatic and temporal variables. Hours postsunrise and relative humidity emerged as the top variables influencing surface activity in gravid females. Hours postsunrise and ambient air temperature emerged as the top variables influencing surface activity in males. Our data suggest that activity in H. platirhinos occurs as a function of several environmental, temporal, and ecological factors and varies on the basis of sex and reproductive class. When considering activity, future studies on terrestrial ectotherms should consider not only the relationships of sex, but of reproductive class as well.
The propensity for defensive biting in turtles should vary ontogenetically. In species with plastral kinesis, the effectiveness of retraction into the shell as a defensive mechanism increases with body size. Therefore, adults should be less likely to bite and more likely to retract than are juveniles. We tested this hypothesis by measuring biting propensity and retraction propensity from an ontogenetic series of Kinosternon sonoriense (Sonora Mud Turtle), a species with plastral kinesis. As predicted, biting in K. sonoriense was restricted to younger, smaller turtles, whereas capacity for retraction was restricted to older, larger turtles.
As road networks continue to expand globally, indirect impacts to adjacent wildlife populations remain largely unknown. Simultaneously, reptile populations are declining worldwide and anthropogenic habitat loss and fragmentation are frequently cited causes. We evaluated the relative influence of three different road characteristics (surface treatment, width, and traffic volume) and habitat features on adjacent populations of Northern Sagebrush Lizards (Sceloporus graciosus graciosus), Plateau Fence Lizards (S. tristichus), and Greater Short-Horned Lizards (Phrynosoma hernandesi) in mixed arid shrubland habitats in southwest Wyoming. Neither odds of lizard presence nor relative abundance was significantly related to any of the assessed road characteristics, although there was a trend for higher Sceloporus spp. abundance adjacent to paved roads. Sceloporus spp. relative abundance did not vary systematically with distance to the nearest road. Rather, both Sceloporus spp. and Greater Short-Horned Lizards were associated strongly with particular habitat characteristics adjacent to roads. Sceloporus spp. presence and relative abundance increased with rock cover, relative abundance was associated positively with shrub cover, and presence was associated negatively with grass cover. Greater Short-Horned Lizard presence increased with bare ground and decreased marginally with shrub cover. Our results suggest that habitat attributes are stronger correlates of lizard presence and relative abundance than individual characteristics of adjacent roads, at least in our system. Therefore, an effective conservation approach for these species may be to consider the landscape through which new roads and their associated development would occur, and the impact that placement could have on fragment size and key habitat elements.
Recent population declines in amphibians associated with mortality in early life stages highlight the need for a better understanding of the environmental factors related to successful survival to metamorphosis. In our study, we closely examine the relative importance of environmental factors to three stages of recruitment for Cascade frogs (Rana cascadae), a declining amphibian, in high-elevation wet meadows. Our results show that local dynamics are strongly associated with breeding site selection, the number of egg masses, and the number of individuals that survive to metamorphosis per egg mass. Rana cascadae does not tend to breed in wet meadows where nonnative trout are present. Survival to metamorphosis per egg mass is lower when hydroperiod of pools is shorter, cattle use is higher, and native insect predators are present. Our results suggest that future management efforts to conserve R. cascadae should strive to protect and restore wet meadows free from nonnative trout, containing many pools with longer hydroperiods, and subjected to minimal cattle use during sensitive development periods.
Monitoring the fates of individuals after release in the wild is essential for building effective species recovery programs. Current conservation efforts for the endangered Wyoming Toad (Anaxyrus baxteri) are limited by the size and number of toads that can be individually marked using invasive tagging techniques. We evaluated the use of natural patterns of wart-like glands on the dorsum of Wyoming Toads as a potential identification technique. We photographed 194 known-identity individuals (822 total images, representing 1,554 true matching-image pairs of the same individuals) from two captive-breeding facilities in 2011 and 2012. Spot patterns provided stable markings from metamorphosis through adult life stages, and naïve observers correctly matched 100% of a subset of photo pairs “by eye.” In contrast, computer-assisted identification performed relatively poorly: the two software platforms tested (Wild-ID and Hotspotter) failed to match 47% and 64% of true matching-image pairs, respectively. The use of higher-quality cameras with faster automatic focusing speeds yielded the largest improvement in matching success of any variable tested when using identification software. Simulated capture–recapture data demonstrated that using software to identify individuals would bias abundance estimates high by up to 920%.
Burmese Pythons (Python bivitattus) are large generalist predators that have established an expanding breeding population in Florida. As a first step in understanding current distributions, and therefore spread potential, we assessed diurnal habitat selection by Burmese Pythons in the southern Everglades using radiotelemetry. Sixteen individual pythons were radio-tracked between September 2006 and December 2009. Habitat variables included land cover, habitat edges, surface water depth, and change in water depth. Python locations were compared to available habitat, both within each snake's home range and across the entire study area, by calculating selection ratio intervals and developing resource selection functions. Habitat selection by Burmese Pythons in south Florida was nonrandom with clear selection of broad-leafed and coniferous forest and avoidance of open water and other habitats with deep water. We concluded that Burmese Pythons selected habitats with a substantial canopy overstory that was without deep flooding, with no strong selection for freshwater emergent macrophyte marsh habitats that dominate (∼ 43%) the study area. We will use these new quantitative insights into python habitat selection to model the potential for this invasive species to expand to new areas within Florida.
Oviposition site selection is critical to increase offspring fitness for aquatic-breeding anurans, which generally lack posthatching parental care. Understanding factors that influence oviposition microhabitat choice would be helpful for managing and controlling invasive amphibians, such as the American Bullfrog (Lithobates catesbeianus), implicated in the decline of anuran populations across its invasive range. Factors that influence bullfrog oviposition microhabitat selection, however, remain mostly unknown. On the basis of field surveys from 2008 to 2013, we investigated 46 oviposition sites used by bullfrogs and 46 adjacent random unused sites and evaluated eight characteristics that could potentially influence oviposition site selection by bullfrogs in Caohai wetland, southwestern China, a global biodiversity conservation hot spot. We used model averaging of generalized linear mixed-effects models, using Akaike information criterion, hierarchical partitioning, and an ordination principal components analysis to analyze site selection. Results revealed that bullfrogs preferred waters with a high proportion of emergent plant coverage, whereas the distance to the nearest boat route decreased the probability of bullfrog oviposition site presence. Our study was one of the first quantitative studies on oviposition microhabitat selection by bullfrogs within their invaded ranges that combined abiotic, biotic, and human activities. We suggest that efforts to control and manage this global invader be directed toward reducing the suitability of breeding microhabitats by targeting areas with dense emergent vegetation, far from human disturbances.
Managing species with intensive tools such as reintroduction may focus on single sites or entire landscapes. For vagile species, long-term persistence will require colonization and establishment in neighboring habitats. Therefore, both suitable colonization sites and suitable dispersal corridors between sites are required. Assessment of landscapes for both requirements can contribute to ranking and selection of reintroduction areas, thereby improving management success. Following eradication of invasive American Bullfrogs (Lithobates catesbeianus) from most of Buenos Aires National Wildlife Refuge (BANWR; Arizona, United States), larval Chiricahua Leopard Frogs (Lithobates chiricahuensis) from a private pond were reintroduced into three stock ponds. Populations became established at all three reintroduction sites followed by colonization of neighboring ponds in subsequent years. Our aim was to better understand colonization patterns by the federally threatened L. chiricahuensis which could help inform other reintroduction efforts. We assessed the influence of four landscape features on colonization. Using surveys from 2007 and information about the landscape, we developed a habitat connectivity model, based on electrical circuit theory, that identified potential dispersal corridors after explicitly accounting for imperfect detection of frogs. Landscape features provided little insight into why some sites were colonized and others were not, results that are likely because of the uniformity of the BANWR landscape. While corridor modeling may be effective in more-complex landscapes, our results suggest focusing on local habitat will be more useful at BANWR. We also illustrate that existing data, even when limited in spatial or temporal resolution, can provide information useful in formulating management actions.
The conservation and management of Blanding's Turtles (Emydoidea blandingii) has attracted considerable attention in recent years as the species is recognized as being at risk over much of its current range. We used seven variable microsatellites to examine five populations from Ontario (St. Lawrence River valley) to southeastern New York (Dutchess County) to assess genetic diversity and estimate gene flow, genetic drift, and the roles of distance and topography in dispersal of Blanding's Turtles. Three peripheral populations in the St. Lawrence River valley exhibited low levels of differentiation (FST < 0.07); past or current gene flow between these adjoining populations has likely been facilitated by the St. Lawrence River. A disjunct population in Dutchess County was divergent from other populations but showed no signs of loss of genetic diversity. A recently discovered population in Saratoga County displayed low levels of genetic diversity, possibly indicating that it has been isolated for some time. The St. Lawrence River valley populations appear to have sufficient habitat corridors to have maintained gene flow after the Wisconsin glaciation. This may not reflect current connectivity, however, and conservation measures should be aimed at maintaining connectivity and decreasing road mortality. Management plans for the Dutchess County population should consider maintaining connectivity among subpopulations a priority to avoid losing unique alleles to genetic drift. The Saratoga area should be investigated for other pockets of individuals that could potentially contribute to overall genetic diversity. The discontinuous distribution of this species within New York, coupled with regional differences in genetic variation, highlight the importance of maintaining all extant populations.
The largest extant New Zealand gecko, Hoplodactylus duvaucelii (Duvaucel's Gecko), is a nocturnal, viviparous species of conservation concern. Hoplodactylus duvaucelii, once widespread throughout New Zealand, is now confined to offshore islands, the majority of which are free from all introduced mammalian predators (mice, rats, cats, mustelids, brushtail possums). A single H. duvaucelii, caught within a fenced reserve on North Island in 2010 was genotyped to determine whether it represents a recent introduction or a previously unknown native relict population. Genotypes from seven nuclear loci and a minimum spanning network of mtDNA haplotypes revealed two clusters representing southern (Cook Strait) and northern island populations. This genetic structure is concordant with variation between these two groups observed in body size, color pattern, and scalation. The mainland specimen was found to possess a mixture of morphological character states typical of northern and southern island populations. Although the individual possessed a unique mitochondrial haplotype, high heterozygosity, and a private nuclear allele, it was no more genetically distinct than conspecifics from isolated island populations. Comparisons with live captive geckos failed to provide evidence that the aberrant specimen represented a recent translocation. We infer that H. duvaucelii has survived naturally on North Island at very low population densities since the human-mediated introduction of novel predators 800 years ago. Our findings suggest a novel conservation priority, which should be prioritized for additional study in the immediate future.
Surface retreats (rocks, logs, and bark piles) provide important surface microhabitat for plethodontid salamanders; inconsistencies exist, however, among studies of retreat use by salamanders in natural habitats. I determined the relationships among 14 taxa (12 species, 2 hybrids) of plethodontid salamanders and retreat area and type as well as patterns of occurrence when multiple salamanders were found under the same retreat. Plethodontid salamanders in the Great Smoky Mountains National Park used both woody retreats (logs and bark piles) and larger retreats more often than expected. Additionally, the presence, number, area, and mass of salamanders were associated positively with retreat area; however, the variation explained by retreat area was low. Elevation was the best predictor of the relationship between salamanders and retreat area; low and mid elevations had a more positive relationship between salamanders and retreat area. When multiple salamanders were found under the same retreat, species pairings were no different from expected based on the species present at each site, and paired salamanders were more similar in size than expected. This study revealed patterns of retreat use for terrestrial plethodontid salamanders and makes suggestions for future studies to clarify the relationships between salamanders and retreats.
We investigated the ecology, distribution, and density of Florida Box Turtle (Terrapene carolina bauri Taylor, 1895) populations in the Ten Thousand Islands (TTI), an estuarine mangrove ecosystem in southwestern Florida. The distribution and ecology of Box Turtles in this region and this habitat type have not been previously investigated. The study area encompassed 18 islands and included five natural islands, 13 man-made shell islands, and adjacent mangrove environments. Two hundred and twenty-nine live Box Turtles and 95 Box Turtle shells were detected a total of 409 times on seven of the 18 islands. The seven islands where Box Turtles were detected ranged in size from 7.3 to 31.0 ha and were ancient shell work sites, apparently constructed by the Calusa or other Prehistoric Indians approximately 1,900 to 900 years before present (ybp). Box Turtles were not detected on natural islands. We detected Box Turtles primarily in subtropical hardwood hammock forests, but we detected 10% of turtles in mangrove or mangrove ecotones. Males were larger than females across all sites. We detected a significant difference in body size between living and dead adults. We estimated population size on four shell work islands to range from 43 (SE = 3.5) turtles to 270 (SE = 244) turtles and estimated densities ranging from 2.7–12.2 turtles/ha. Box Turtles on the shell work islands of the TTI are a unique example of populations living on ancient, manmade islands. However, known populations are small and isolated and may be susceptible to increased human recreational use, mechanized vegetation management, or predation by raccoons.
Microhabitat use is an important aspect of an organism's niche, often influencing both intra- and interspecific interactions such as competition. To reduce competitive interactions, species may shift their behavior when in sympatry to gain greater access to resources, resulting in patterns of habitat partitioning. Previous studies have described structural microhabitat partitioning in Phelsuma geckos with the likely cause being interference competition. Such interference competition also may lead to temporal microhabitat partitioning. We investigated the presence of temporal habitat partitioning in Phelsuma geckos from Mauritius and the relation of partitioning to competition. We found temporal variation in microhabitat use for Mauritian Phelsuma. However, this variation was not clearly associated with the presence of other focal Phelsuma species, suggesting competition may not be responsible for the observed pattern. Temporal habitat partitioning in Mauritian Phelsuma geckos may be attributable to historical competition or other factors such as thermoregulation, food availability, or predator avoidance. We encourage future studies to investigate the mechanisms of temporal microhabitat variation.
Bromeliads are used by many frog species because of their capacity to accumulate rainwater. The bromeligenous frog, Phyllodytes luteolus (Yellow Heart-Tongued Frog), uses bromeliads for its entire life cycle including shelter, foraging, and reproduction. We evaluated the effect of plant morphometrics and the properties of water accumulated in bromeliads on the selection of these plants by P. luteolus. We sampled 103 bromeliads of which 41 were unoccupied and 62 were occupied by P. luteolus. Results suggest that bromeliad occupation by P. luteolus is nonrandom. We found that occupied plants were shorter in height, had a greater number of leaves, and had lower water conductivity than did unoccupied plants. Males were more likely to occupy plants with more leaves than were females. Plant selection may be related to the reproductive success of P. luteolus because frogs using plants with more leaves and lower conductivity may experience reductions in competition for space, predator encounters, and desiccation. Considering that illegal bromeliad harvesting threatens many bromeligenous frogs, improved understanding of bromeliad selection may determine which bromeliad species should be targeted for conservation to ensure the population viability of frogs.
Bromélias são usadas por muitas espécies de anuros, devido à sua capacidade de acumular água da chuva. O anuro bromelígena Phyllodytes luteolus, usa bromélias para todo o seu ciclo de vida, incluindo abrigo, forrageamento e reprodução. Avaliamos o efeito da morfometria e as propriedades da água acumulada em bromélias na seleção dessas plantas por P. luteolus. Foram amostradas 103 bromélias, das quais 41 estavam desocupadas e 62 foram ocupadas por P. luteolus. Os resultados sugerem que a ocupação de bromélia por P. luteolus não é aleatória. Descobrimos que as plantas ocupadas eram menores, tinham um maior número de folhas, e tiveram menor condutividade da água que as plantas desocupadas. Os machos tendem a ocupar plantas com mais folhas do que as fêmeas. A seleção de bromélias pode estar relacionada com o sucesso reprodutivo de P. luteolus; por exemplo, os anuros que utilizam plantas com mais folhas e menor condutividade podem experimentar uma redução da concorrência por espaço, encontro predador, dessecação, porque mais axilas com água estarão disponíveis, resultando em um maior sucesso reprodutivo. Considerando-se que o extrativismo ilegal de bromélias ameaça muitos anuros bromelígenas, a melhor compreensão da seleção bromélia pode determinar as espécies de bromélias que devem ser priorizadas para a conservação a fim de assegurar a viabilidade da população de anuros.
Variation in predation risk plays an important role in shaping prey behavior, morphology, life history, population dynamics, and community structure in freshwater systems. Anuran larvae are important prey in freshwater communities and spatiotemporal variation in risk can arise from changes in the number and identity of predators; however, our understanding of variation in abundance, identity, and foraging rates for natural predator assemblages in tropical pond communities is limited. We surveyed ponds near Gamboa, Panama in 2004 and 2010 to estimate variation in predator communities of tadpoles over space and time. We also conducted short-term predation trials with the 10 most common predators using hatchling tadpoles of two widespread Neotropical frog species, Red-Eyed Treefrogs (Agalychnis callidryas) and Pantless Treefrogs (Dendropsophus ebraccatus). Predator abundance varied nearly threefold across ponds within a single year and as much as 19-fold within a pond across years. Dominant taxa also varied, with backswimmers (Notonectidae), poeciliid fish, or libellulid dragonfly naiads being the most common depending upon pond and year. Predation trials revealed that prey-specific predation rates differed among predator taxa. Some presumed predators did not consume hatchlings, whereas others consumed >90% of prey. The smaller D. ebraccatus hatchlings generally experienced higher predation rates; however, large invertebrate predators like aeshnid dragonfly naiads, giant water bugs, and fishing spiders consumed more A. callidryas. These results suggest that strong but variable larval-stage risk may be an important selective factor shaping tadpole communities and phenotypes in Neotropical ponds.
Variación en el riesgo de depredación tiene una función importante sobre el comportamiento, morfología, historia de vida, dinámicos de poblaciones y la estructura de comunidades en sistemas acuáticos. Las larvas de ranas, renacuajos, son presas importantes en las comunidades acuáticas y la variación espacio-temporal en el riesgo puede deberse a cambios en el número y la identidad de los depredadores. Sin embargo, nuestra comprensión de la variación en la abundancia, la identidad, y las tasas de forrajeo de los depredadores de las comunidades de estanques tropicales es limitado. Encuestamos a cerca de los estanques de Gamboa, Panamá, en 2004 y 2010 para estimar la variación en las comunidades de depredadores de renacuajos en el espacio y el tiempo. También realizamos pruebas de depredación a corta plazo con los 10 depredadores más comunes utilizando los renacuajos de dos especies de ranas neotropicales con ámplios rangos, ranas arborícolas de ojos rojos (Agalychnis callidryas) y sin pantalones (Dendropsophus ebraccatus). La abundancia de los depredadores varió casi tres veces a través de estanques dentro de un solo año y tanto como 19 veces en un estanque a través de años. Las especies dominantes también variaron, con Notonecta, peces poeciliidos y náyades siendo el más común, dependiendo de la charca y año. Las pruebas de depredación revelaron que la depredación de cada especie de presa diferían entre los taxones depredadores. Algunos depredadores presuntos no consumieron renacuajos, mientras que otros consumieron >90% de las presas. El renacuajo más pequeño, D. ebraccatus, generalmente sufrido tasas de depredación mas altas, pero los depredadores mas grandes, como las ninfas de libélulas de la familia Aeshnidae, Belostoma y arañas de pesca, consumieron más A. callidryas. Estos resultados sugieren que el riesgo fuerte pero variable durante la etapa de renacuaj
The development of appropriate management and recovery plans requires a better understanding of the demography of endangered amphibians. In this study longevity, age at maturation, age structure, growth rates, and growth patterns of a local population of the endangered Kaiser's Mountain Newt, Neurergus kaiseri, in southwestern Iran were studied using skeletochronology. To estimate the age of individuals, numbers of lines of arrested growth was used in the periosteal bone obtained from cross-sections of 73 live newt toes. The maximum observed longevity was 14 yr in males and 12 yr in females. Mean ± SE longevity recorded for males (6.81 ± 0.58 yr) and females (7.74 ± 0.34 yr) was not significantly different (P = 0.14, t-test, n = 73). The minimum age at sexual maturity in both sexes was 4 yr. Mean ± SE snout–vent length (SVL) in females (63.31 ± 4.58 mm) was higher than in males (54.68 ± 3.74 mm) (P = 0.007, t-test, n = 73). The growth curve for SVL was best described by the von Bertalanffy model compared with Gompertz and logistic growth models (on the basis of Akaike information criterion and coefficient of determination).
Many studies suffer from imperfect detection probability, i.e., species are not detected when individuals may be present. In occupancy studies, detection probability is often treated as a nuisance variable. When used as a primary variable of interest, detection probability can be examined as a function of sampling covariates with the goal of maximizing the probability of encountering target species. Efforts to determine which methods maximize detection probability will benefit monitoring programs, particularly for species that are difficult to detect. We used three sampling methods, leaf litter bag (LLB) surveys, visual encounter surveys (VES), and flip and search (FS) methods to detect larval Spring Salamanders (Gyrinophilus porphyriticus). We estimated occasion-specific estimates of detection and used an analysis of variance to determine if detection probability varied among sampling methods. We found the FS method yielded higher detection estimates than did the LLB and VES. In addition, occupancy estimates derived from FS sampling changed drastically when compared among other single-method models, suggesting that LLB and VES gave biased estimates of occupancy related to a low probability of detecting Spring Salamanders at occupied sites. Furthermore, our results suggest the FS method provided higher detection probability estimates as compared to estimates derived from models that combined all sampling methods. In conclusion, efforts to monitor Spring Salamanders should rely on FS for sampling populations to maximize detection probability to reduce costs and increase effectiveness for large, widespread research projects.
The role of melatonin in altering cell-mediated nonspecific immune responses has been documented in mammals, but there is no report available in reptiles. We designed the present study to evaluate the role of melatonin in altering innate immune responses of leukocytes in freshwater snakes. We administered melatonin injections (dose: 5 and 10 μg/g body weight) during evening hours. Animals receiving saline served as controls. Snakes were sacrificed after 10 and 20 days. We studied the alteration in total and differential leukocyte counts, blood neutrophil phagocytosis, nitric oxide production, superoxide production, and lymphoproliferation. We did not observe a consistent and significant change in total leukocyte count, whereas monocyte, eosinophil, and basophil counts were increased in response to melatonin. Interestingly, the phagocytic response of neutrophils was inhibited when treated with melatonin. Nitrite release and superoxide production by leukocytes were significantly higher in snakes receiving melatonin injections. Exogenous melatonin also enhanced the mitogen-induced lymphocyte proliferation in a manner dependent on dose and duration of melatonin treatment.
Plethodontid salamanders are often monitored as indicator species for mature forest ecosystem health. In addition to relative abundance, differences in standard metabolic rate (SMR) between harvest treatments have been used to explain physiological stress in response to timber harvest. Nearly ubiquitous in forested stands throughout the northeastern United States, the Eastern Red-Backed Salamander (Plethodon cinereus) is often the focal species of such studies. In 2010, a predictive multiple regression equation was developed to calculate SMR of P. cinereus to 95% accuracy using salamander body mass and temperature. This method of SMR estimation has been implemented in field studies as a measure of salamander health. In these studies, temperature regime is the only variable measured, and SMR is calculated by standardizing on a 1-g salamander. In this study, we measured both body mass and temperature of each salamander encountered in harvested and unharvested stands and compared the published SMR calculation technique with SMR calculated using observed temperature and body mass data. We found larger variability in temperature in harvested stands using both methods but did not identify a similar trend in the SMR of observed salamanders. Differences in salamander body mass and snout–vent length between harvested and unharvested stands in Fall 2013 suggest that researchers should use caution when making claims about SMR when data on salamander body mass has not been measured.
Measuring standard metabolic rates in newts remains a complicated task despite substantial methodological and technological advances in the field. We examined the influence of aquatic versus terrestrial conditions in respirometry chambers on measurements of respiratory gases and motor activity in Alpine Newts, Ichthyosaura alpestris, during their aquatic phase. Aquatic conditions during intermittent respirometry trials biased values of carbon dioxide production more than values of oxygen consumption, which caused marked differences in estimates of respiratory quotient. Placing newts in water increased their motor activity relative to terrestrial conditions during respirometry trials, which made obtaining representative estimates of standard metabolic rates complicated. We conclude that the absence of water, rather than aquatic conditions in respirometry chambers, produces more-accurate metabolic measurements in newts during their aquatic phase.
A newly discovered species of arboreal alligator lizard of the genus Abronia is described from the Sierra Madre del Sur of Oaxaca, Mexico. It appears to be most closely related to A. mixteca and A. oaxacae, but differs from these species (and others in the subgenus Abronia) in a number of features, including the combination of having two primary temporals contacting the postocular series, the anterior superciliary contacting the cantholoreal, six to eight nuchals in a transverse row across the nape, minimally seven to eight scales between large nuchals and ventral scales on neck, and 32–35 transverse rows of dorsal scales. This new species is the only species of Abronia known from the central and western portions of the Sierra de Miahuatlán in the southern part of the Sierra Madre del Sur, although A. oaxacae occurs to the east in this range. Many of the arboreal and secretive species of Abronia have avoided discovery until relatively recently, with about a third of known species described in the last 3 decades.
Se describe una nueva especie de lagartija lagarto arbórea del género Abronia de la Sierra Madre del Sur de Oaxaca, México. Parece estar más relacionada a A. mixteca y A. oaxacae, pero difiere de estas especies y de otras del subgénero Abronia en varios caracteres, incluyendo la combinación de tener dos temporales primarias contactando la serie postocular, la superciliar anterior en contacto con la cantoloreal, 6–8 nucales en hilera transversal sobre la nuca, un mínimo de 7–8 escamas entre las nucales grandes y las escamas ventrales del cuello, y 32–35 hileras transversales de escamas dorsales. Esta nueva especie es la única del género Abronia conocida de las porciones central y occidental de la Sierra de Miahuatlán en la región sur de la Sierra Madre del Sur, aunque A. oaxacae ocurre al oriente de esta serranía. Muchas de las especies de Abronia con hábitos secretos y arbóreos han evadido ser descubiertas hasta hace poco, aproximadamente una tercera parte de las especies han sido descritas en las últimas tres décadas.
As a first step toward making sense of an infamously enigmatic and taxonomically problematic group of Philippine blind snakes, we redescribe Malayotyphlops luzonensis (Taylor, 1919) and Malayotyphlops ruber (Boettger, 1897) and clarify their taxonomic status with respect to each other and to additional phenotypically similar taxa. We also describe two other new species of Malayotyphlops from the Sierra Madre Mountain Range of northern Luzon Island, each on the basis of a single specimen. We suspect that species diversity of the typhlopid fauna of the Philippines is severely underestimated, with progress towards a comprehensive understanding of this group most hampered by a lack of sufficient comparative material available in biodiversity repositories.
Most miniaturized froglets of the genus Brachycephalus occur in isolation in slopes of mountain ranges at elevations varying from 600 to 1,800 m in the Atlantic Forest of eastern Brazil. For organisms such as Bracycephalus with spatially discontinuous distributions, a fundamental task is to determine whether observed patterns of variation are consistent with geographic differentiation among allopatric populations within a single species or are suggestive of a potential species boundary. We address this problem by focusing on continental and island population samples potentially assignable to Brachycephalus nodoterga (Anura: Brachycephalidae) from the perspective of variation in qualitative and quantitative morphological traits and DNA sequences. Population samples from continental and island populations share color characteristics, qualitative traits, and multivariate patterns of variation and covariation in cranial metric traits. Comparative analysis of DNA sequences showed the magnitude of molecular distances between B. nodoterga and Brachycephalus ephippium to be 1 order of magnitude larger than molecular distances within B. nodoterga and B. ephippium. We interpret the combined morphological and molecular evidence to indicate that continental and island population samples examined here are conspecific. Therefore, by defining species boundaries for B. nodoterga, we also established minimal estimates of its distribution.
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