Predicting Hot Spots of Herpetofauna Road Mortality Along Highway Networks

ABSTRACT Road mortality is often spatially aggregated, and there is a need for models that accurately and efficiently predict hot spots within a road network for mitigation. We surveyed 145 points throughout a 353-km highway network in New York State, USA, for roadkill of reptiles and amphibians. We used land cover, wetland configuration, and traffic volume data to identify features that best predicted hot spots of herpetofauna road mortality. We resampled 40 points an additional 4 times over 4 years to evaluate temporal repeatability. Both amphibian and reptile road mortality were spatially clustered, and road-kill hot spots of the 2 taxa overlapped. One survey provided a valid snapshot of spatial patterns of road mortality, and spatial patterns remained stable across time. Road-kill hot spots were located where wetlands approached within 100 m of the road, and the best predictor was a causeway configuration of wetlands (wetlands on both sides of the road). We validated causeways as predictors of road mortality by surveying 180 causeways and 180 random points across 5 regions (17,823 km²) of northeastern New York. Causeways were 3 times more likely than random locations to have amphibian and 12 times more likely to have reptile mortality present, and causeways had a 4 times higher total number of amphibian roadkill and 9 times higher reptile roadkill than did random points. We conclude it is possible to identify valid predictors of hot spots of amphibian and reptile road mortality for use when planning roads or when conducting surveys on existing roads to locate priority areas for mitigation.     

Comparison of road surveys and circuit theory to predict hotspot locations for implementing road-effect mitigation

The mitigation of road-effects on wildlife, especially road mortality and habitat fragmentation, has become increasingly common in the last 20 years. However, exclusion fencing and habitat connectivity structures can be very costly and several questions remain regarding how to best determine locations that will optimize mitigation success. Based on data collected across several years and across multiple landscapes and taxa, we present a comparative analysis of two methods: road surveys and circuit theory, and review their benefits and challenges to better inform decision making. Road surveys were completed in two locations over three years for large mammals and herpetofauna to identify road crossing hotspots. Circuit theory was also applied to these systems to identify crossing hotspots using habitat resistance models. The location, number and width of hotspots were compared between methods. Hotspot distributions were similar between methods for some herpetofauna, but different for Mammals, and road surveys produced a significantly greater number of smaller hotspots compared to circuit theory, implying that road surveys provide better hotspot resolution. As circuit model complexity increased, the number and width of hotspots decreased, diffusing across the landscape. Road surveys were better at predicting optimal crossing structure location at a local scale; however, circuit theory is less costly, and can be useful at large scales. As both methods can offer valuable information, we argue that the combination of these two approaches provides a strong basis for managers and biologists to make informed decisions about costly mitigation measures, optimizing both conservation benefits and limited funding.     

Biogeography of the Shimba Hills ecosystem herpetofauna in Kenya

The Shimba Hills ecosystem along the south coast of Kenya is a key East African biodiversity hotspot.Historically, it is biogeographically assignable to the East African coastal biome. We examined the current Shimba Hills herpetofauna and their zoogeographical affinities to the coastal forests and nearby Eastern Arc Mountains biodiversity hotspots.The key studied sites included the Shimba Hills National Reserve, forest reserves, Kaya forests, and adjacent private land. Data on herpetofaunal richness were obtained from recent field surveys,literature, and specimens held at the National Museums of Kenya, Herpetology Section Collection,Nairobi. The Makadara, Mwele, and LongoMwagandi forests within the Shimba Hills National Reserve hosted the highest number of unique and rare species. Generally, the forest reserves and Kaya forests were important refuges for forestassociated species. On private land, Mukurumudzi Dam riparian areas were the best amphibian habitat and were host to three IUCN(Red List) EndangeredEN amphibian species, namely, Boulengerula changamwensis, Hyperolius rubrovermiculatus, and Afrixalus sylvaticus, as well as one snake species Elapsoidea nigra. Using herpetofauna as zoogeographic indicators, the Shimba Hills were determined to be at a crossroads between the coastal forests(13 endemic species) and the Eastern Arc Mountains(seven endemic species).Most of the Eastern Arc Mountains endemic species were from recent records, and thus more are likely to be found in the future. This 'hybrid' species richness pattern is attributable to the hilly topography of the Shimba Hills and their proximity to the Indian Ocean.This has contributed to the Shimba Hills being the richest herpetofauna area in Kenya, with a total of 89 and 38 reptile and amphibian species, respectively.Because of its unique zoogeography, the Shimba Hills ecosystem is undoubtedly a key biodiversity area for conservation investment.     

Reptile, amphibian, and lemur diversity of the Malahelo Forest, a biogeographical transition zone in southeastern Madagascar

Ambatorongorongo Mountain lies at the historical intersection betweenhumid, spiny, and littoral forests in southeastern Madagascar. We report theresults of surveys of the herpetofauna and lemurs occurring in Malahelo Forest,a small (<25 ha) forest fragment lying on the western slope ofAmbatorongorongo Mountain. There are at least 41 reptile, 11 amphibian, and 7lemur species in this forest, including several that are endemic to southeasternMadagascar and are at severe risk of extinction. The species richness of theMalahelo fauna is comparable to that of even the largest forest reserves in theregion. We also evaluate the similarity of the Malahelo herpetofauna to that ofnearby humid, spiny, and littoral forests to assess the biogeographic affinitiesof its amphibians and reptile assemblages. Both groups contain speciescharacteristic of each of the three surrounding forest types, but thebiogeographic patterns appear to differ for amphibians and reptiles. Overall,the herpetofauna and lemurs of the Malahelo Forest indicate that it is a remnantof a biogeographic transition zone between the major forest types ofsoutheastern Madagascar. The combination of high species richness, regionalendemics, and unique herpetofaunal and lemur assemblages should make MalaheloForest a high conservation priority, and we give recommendations for protectingwhat remains of this important transitional forest.     

Integrating field surveys and remote sensing data to study distribution, habitat use and conservation status of the herpetofauna of the Comoro Islands

We studied the non-marine reptile and amphibian species of the volcanic Comoro archipelago in the Western Indian Ocean, a poorly known island herpetofauna comprising numerous microendemic species of potentially high extinction risk and widespread, non-endemic and often invasive taxa. According to our data, the Comoro islands are inhabited by two amphibian species and at least 28 species of reptiles although ongoing genetic studies and unconfirmed historical records suggest an even higher species diversity. 14 of the 28 currently recognized species of terrestrial reptiles (50%) and the two amphibians are endemic to a single island or to the Comoro archipelago. The majority of species are most abundant at low elevation. However, a few endemic species, like the gekkonid lizards Paroedura sanctijohannis and Phelsuma nigristriata, are more common in or even confined to higher altitudes. We created habitat maps from remotely sensed data in combination with detailed species distribution maps produced using comprehensive data from field surveys between 2000 and 2010, literature, and historical locality records based on specimens in zoological collections. Using these data, we assessed the conservation status of the endemic terrestrial reptiles and amphibians according to the IUCN Red List criteria. Our results show that although little area of natural forest remains on the Comoros, many species are abundant in degraded forest or plantations. Competition and predation by invasive species appears to be the most important threat factor for the endemic herpetofauna, together with habitat degradation and destruction, which further favours invasive species. We propose the status Endangered for three species, Vulnerable for one species, Near Threatened for six species, Least Concern for four and Data Deficient for two species. The endemic subspecies Oplurus cuvieri comorensis is proposed for the status Critically Endangered. Based on the results of this study, seven areas of importance for reptile and amphibian conservation on the Comoros are identified. This study shows how remote sensing data can contribute to increasing accuracy and objectiveness of conservation assessments.     

Influence of landscape and vegetation characteristics on herpetofaunal assemblages in Gulf Coastal Plain pine forests

Longleaf pine (Pinus palustris) savanna characterized by open-canopy, diverse herbaceous vegetation, and high amounts of bare soil once covered much of the southeastern United States Coastal Plain. The unique structural and vegetative conditions of this ecosystem support endemic reptiles and amphibians that have declined as longleaf pine forests have been lost or degraded. Private working pine (Pinus spp.) forests managed for timber production now occur throughout the southeastern United States and have replaced much of the historical longleaf pine savanna. The examination of herpetofaunal (reptile, amphibian) communities in private working loblolly pine (P. taeda) landscapes, particularly in the western Gulf Coastal Plain is lacking. Using repeated field surveys and hierarchical community occupancy models, we examined occupancy and species richness of herpetofauna across 81 sites spanning gradients of management practices, vegetative conditions, and soil composition in northwestern Louisiana, USA, 2017–2019. Young pine stands (<6 yr) exhibited structural characteristics most similar to mature longleaf pine reference sites (>30 yr), while mid-aged stands (13–26 yr) often featured closed canopy and dense midstory. Vegetation conditions varied widely depending on landscape characteristics and site-specific disturbance regimes. We documented 43 species of herpetofauna, including 9 open-pine-associated species. Occupancy of open-pine-associated herpetofauna was positively associated with open-canopy and understory conditions, and sandy soil area. Sites providing open-canopy conditions were often occupied by open-pine-associated species regardless of overstory type and disturbance method. Overall richness of herpetofauna was greatest at sites with moderate canopy cover outside of sandy soil regions. Working pine landscapes in the western Gulf Coastal Plain can support diverse herpetofaunal assemblages, including open-pine-associated species, when management practices maintain open-canopy conditions on sandy, upland soils. More broadly, our results provide insight into how forest management practices affect herpetofauna and may guide practices that can contribute to conservation value of working pine forests.     

Biological diversity of a temporary pond herpetofauna in north Florida sandhills

From 1985 through 1990, the herpetofauna of a temporary pond in an uplands longleaf pine sandhills community in north-central Florida was monitored. A drift fence completely encircled the pond. Animals were captured in pitfall traps and marked as they entered and exited the pond basin. I captured 16 155 individuals of 42 species (16 amphibians, 26 reptiles). The species richness, diversity (using Margalef's Diversity Index) and dominance (using the Berger-Parker Index) varied among years. Between 62.5% and 87.5% of the amphibian species and 65% to 81% of the reptile species were captured in any one year. Daily amphibian capture was positively correlated with rainfall, whereas reptile capture was either not correlated or weakly negatively correlated with rainfall. Hydroperiod duration was not correlated with the numbers of either amphibians or reptiles captured. Neither the amphibian nor the reptile community showed any trends in diversity or dominance indices during the course of the study, although both communities were dominated by a few species. However, the species responsible for community dominance changed somewhat as the study progressed. Assessing the results of this study is hampered by the lack of comparable studies elsewhere, expected natural fluctuations of amphibian populations, and a prolonged drought, especially during the latter stages of the study. The herpetological community at Breezeway Pond does not appear to follow theoretical predictions of community response to stress. Temporary ponds are important centres of herpetofaunal biodiversity in uplands sandhills communities. Long-term studies are needed to monitor the composition, structure, and functional interactions of their resident species.     

Comparative use of active searches and artificial refuges to detect amphibians in terrestrial environments

Artificial refuges (cover boards) are commonly used to survey and monitor herpetofauna in many parts of the world. Despite the extensive use of artificial refuges in mesic environments, their effectiveness for detecting amphibians in temperate zones has rarely been examined. We compared amphibian detection probabilities between two survey methods; active searches of natural habitat and artificial refuges of three different types (corrugated steel, roofing tiles and timber railway sleepers). Our study area included five bioregions encompassing a 1180‐km latitudinal gradient across a modified, temperate eucalypt woodland vegetation community in south‐eastern Australia. We deployed 14 778 artificial refuges in terrestrial environments, within patches of remnant vegetation, and collected presence and abundance data on herpetofauna between 1999 and 2017. We used Bayesian logistic regression to identify the most effective survey method for detecting frog species across all bioregions. We modelled frog detections by fitting survey method, time since refuge deployment and rainfall prior to each survey. We detected 3970 individuals from 18 frog species. Overall, we found active searches and timber substrates most effective for detecting a broad range of species, although detection rates were driven by the numerically abundant spotted marsh frog Limnodynastes tasmaniensis. Timber refuges were effective for detecting several burrowing species, whereas active searches were effective at detecting habitat generalists. Quadratic effects of rainfall prior to survey as opposed to linear effects of time since artificial refuge placement was important in explaining frog detection rates in some bioregions. Active searches, timber railway sleepers and sheets of corrugated steel provide complimentary survey methods for detecting amphibians, although detection rates are influenced by rainfall patterns. Artificial refuges provide a time‐effective and standardized method for studying amphibians in their non‐breeding terrestrial environment and should be incorporated into future surveys and biodiversity monitoring programmes.     

江西齐云山自然保护区两栖爬行动物资源调查与区系分析

为掌握江西齐云山自然保护区野生动物资源现状,促进自然保护区的有效管理和建设,作者于2007年1月10～19日、5月16～24日、7月26日～8月8日,前后3次对该保护区两柄爬行动物资源进行了实地考察.调查结果显示,齐云山保护区现已记录72种两栖爬行动物,隶属5目18科.其中两栖纲2目7科24种,爬行纲3目11科48种.齐云山保护区动物地理区划属东洋界华中区东部丘陵平原亚区,其区系组成以60种东洋界种类占明显优势,其余12种均为广布种,无古北界物种分布.大眼斜鳞蛇福建亚种(Pseudoxenodon macrops fukienensis)和寒露林蛙(Rana hanluica)为江西省两栖爬行动物新纪录,福建钝头蛇(Pareas stanleyi)为江西省赣南地区爬行动物新纪录.齐云山保护区是海南棱蜥後(Tropidophorus hainanus)和福建华珊瑚蛇(福建丽纹蛇)(Sinomicrurus kettoggi)在江西省的第二个发现地,是海南闪鳞蛇(Xenopeltis hainanensis)在江西省的第三个采集地.通过平均动物区系相似性分析发现,齐云山地理位置独特,是华中区和华南区物种重要的扩散过渡地域.最后对齐云山保护区的保护与管理工作提出了建议.     

江西桃红岭梅花鹿国家级自然保护区爬行动物资源调查

江西桃红岭梅花鹿自然保护区自成立以来,从未进行过爬行动物资源调查。为掌握保护区爬行动物资源现状,加强生物多样性保护,2005年4月下旬～5月上旬、8月中旬;2006年8月上旬,前后3次对该保护区爬行动物资源进行了实地考察,首次报道保护区现已记录27种爬行动物,隶属3目9科,占江西省80种爬行动物的33．75％。其中东洋界种类有19种,广布种8种,无古北界物种分布。区系组成上明显地以东洋界物种（特别是华中区和华南区共有种17种）为主,这与保护区在动物地理区划上属东洋界华中区东部丘陵平原亚区相一致。此次考察增加赣北（鄱阳湖）平原省爬行动物新记录5种,分别是绞花林蛇、黑眉锦蛇、中国水蛇、渔游蛇、舟山眼镜蛇;对保护区爬行动物的分布和资源现状进行了分析,并提出了保护对策。     

Impacts of climate change on the amphibians and reptiles of Southeast Asia

Amphibians and reptiles will be adversely affected by projected rapid changes in climate in the next decades. Here, we review the known and potential impacts of climate change on the Southeast Asian amphibians and reptiles and make mitigation recommendations for both research and policy. Current amphibian and reptile distributions and ecologies mirror climate patterns, and we expect that adaptation to changes in these parameters will be too slow relative to their rate of expected change, and that pervasive changes will occur to species assemblages, communities, and ecosystem functioning and services. Southest Asia is a network of islands with relatively few mountains, effectively preventing most herpetofauna from migrating away from the effects of climate change. Reflecting specific known and hypothesized physiological and ecological thresholds, we estimate that in <50 years, amphibians and reptiles in Southeast Asia will have reached or exceeded most limits in their abilities to adapt to the effects of climate change and that temperature dependent sex determination, higher metabolic rates, and less bio-available water will have severe and irreversible effects on these organisms. We suggest that human decision-making and policy development have already lagged and that societal change is happening too slowly for effective mitigation. If we are to avert devastating loss of biodiversity and a complete meltdown of ecosystem services, we must quickly change our attitudes and thinking about how we interact with and use biological systems.     

江西庐山自然保护区两栖动物资源调查与评价

于2005—2006年先后3次对庐山自然保护区的两栖动物资源进行了实地调查,得知庐山自然保护区现已记录24种两栖动物,隶属2目8科,占江西省已知39种两栖动物的61．54％。有21种属东洋界种类,3种属广布种,无古北界种类。分别有6、6、3、5和4种两栖类的生态类型属静水型、陆栖-静水型、流水型、陆栖-流水型和树栖型。除大鲵、虎纹蛙为国家二级保护动物外,其余22种两栖动物均属“国家保护的有益的或者有经济、科学研究价值的陆生野生动物”。此次调查采集的小角蟾、阔褶蛙、虎纹蛙、竹叶蛙和花姬蛙为庐山自然保护区两栖动物新记录,并与江西省其它自然保护区讲行了两栖类相似件系数比较,提出了保护建议。     

Climate warming and the decline of amphibians and reptiles in Europe

Aim We explore the relationship between current European distributions of amphibian and reptile species and observed climate, and project species potential distributions into the future. Potential impacts of climate warming are assessed by quantifying the magnitude and direction of modelled distributional shifts for every species. In particular we ask, first, what proportion of amphibian and reptile species are projected to lose and gain suitable climate space in the future? Secondly, do species projections vary according to taxonomic, spatial or environmental properties? And thirdly, what climate factors might be driving projections of loss or gain in suitable environments for species? Location Europe. Methods Distributions of species are modelled with four species–climate envelope techniques (artificial neural networks, generalized linear models, generalized additive models, and classification tree analyses) and distributions are projected into the future using five climate‐change scenarios for 2050. Future projections are made considering two extreme assumptions: species have unlimited dispersal ability and species have no dispersal ability. A novel hybrid approach for combining ensembles of forecasts is then used to group linearly covarying projections into clusters with reduced inter‐model variability. Results We show that a great proportion of amphibian and reptile species are projected to expand distributions if dispersal is unlimited. This is because warming in the cooler northern ranges of species creates new opportunities for colonization. If species are unable to disperse, then most species are projected to lose range. Loss of suitable climate space for species is projected to occur mainly in the south‐west of Europe, including the Iberian Peninsula, whilst species in the south‐east are projected to gain suitable climate. This is because dry conditions in the south‐west are projected to increase, approaching the levels found in North Africa, where few amphibian species are able to persist. Main conclusions The impact of increasing temperatures on amphibian and reptile species may be less deleterious than previously postulated; indeed, climate cooling would be more deleterious for the persistence of amphibian and reptile species than warming. The ability of species to cope with climate warming may, however, be offset by projected decreases in the availability of water. This should be particularly true for amphibians. Limited dispersal ability may further increase the vulnerability of amphibians and reptiles to changes in climate.     

滇西北中甸的两栖爬行动物

滇西北中甸地区共有两栖类13种（亚种）,隶属于2目5科;爬行动物11种（亚种）,隶属于1目2亚目5科。区系成分以东洋界西南区的种类占主导地位,两栖类占84．6％,爬行类占72．7％。区系特点表现为：区系组成单一却特有率高,成分古老又兼具年轻特点,南北动物交汇形成多样化。两栖爬行动物的种群分布与植被类型具有密切的相关性;为适应环境动物形态发生了较多变化。认为中甸地区是动物地理区划中的一关键地区,其两栖爬行类动物的调查及分类研究工作尚需进一步深入。     

湖南壶瓶山国家级自然保护区两栖 爬行动物多样性的时空格局

本研究利用2013至2016年湖南壶瓶山国家级自然保护区巡护监测数据,评估壶瓶山保护区两栖爬行动物多样性水平。壶瓶山保护区在8个监测站点布设了25条两栖爬行动物调查样线,进行常规监测,其中,日间样线14条,夜间样线11条,日间样线平均长度4 km,夜间样线平均长度0.75 km。每个月,每条样线平均调查3次。4年共调查到62种两栖爬行动物,占湖南省两栖爬行动物总种数的38.04%。逐月计算各监测站点的alpha多样性指数和整个保护区的beta多样性指数,按季节比较不同站点间物种组成的Hellinger距离。结果显示,保护区不同位置间、不同的监测站点间以及年际间的两栖爬行动物多样性没有显著差异,提示保护区环境具有相对稳定性。但是,个别位于实验区或邻近实验区的站点,物种组成有着剧烈的波动,表明人为活动影响了两栖爬行动物的分布。另外,保护区两栖爬行动物的物种组成与多样性有着显著的季节差异,这与两栖爬行动物的生物学特性有关。以上结果说明,壶瓶山保护区两栖爬行动物的多样性结构具有稳定性和敏感性的特点,可以考虑用作保护区生物多样性水平的监测指标。     

Spatial variation in the climatic predictors of species compositional turnover and endemism

Previous research focusing on broad‐scale or geographically invariant species‐environment dependencies suggest that temperature‐related variables explain more of the variation in reptile distributions than precipitation. However, species–environment relationships may exhibit considerable spatial variation contingent upon the geographic nuances that vary between locations. Broad‐scale, geographically invariant analyses may mask this local variation and their findings may not generalize to different locations at local scales. We assess how reptile–climatic relationships change with varying spatial scale, location, and direction. Since the spatial distributions of diversity and endemism hotspots differ for other species groups, we also assess whether reptile species turnover and endemism hotspots are influenced differently by climatic predictors. Using New Zealand reptiles as an example, the variation in species turnover, endemism and turnover in climatic variables was measured using directional moving window analyses, rotated through 360°. Correlations between the species turnover, endemism and climatic turnover results generated by each rotation of the moving window were analysed using multivariate generalized linear models applied at national, regional, and local scales. At national‐scale, temperature turnover consistently exhibited the greatest influence on species turnover and endemism, but model predictive capacity was low (typically r² = 0.05, P < 0.001). At regional scales the relative influence of temperature and precipitation turnover varied between regions, although model predictive capacity was also generally low. Climatic turnover was considerably more predictive of species turnover and endemism at local scales (e.g., r² = 0.65, P < 0.001). While temperature turnover had the greatest effect in one locale (the northern North Island), there was substantial variation in the relative influence of temperature and precipitation predictors in the remaining four locales. Species turnover and endemism hotspots often occurred in different locations. Climatic predictors had a smaller influence on endemism. Our results caution against assuming that variability in temperature will always be most predictive of reptile biodiversity across different spatial scales, locations and directions. The influence of climatic turnover on the species turnover and endemism of other taxa may exhibit similar patterns of spatial variation. Such intricate variation might be discerned more readily if studies at broad scales are complemented by geographically variant, local‐scale analyses.     

Meta-analysis reveals impacts of disturbance on reptile and amphibian body condition

Ecosystem disturbance is increasing in extent, severity and frequency across the globe. To date, research has largely focussed on the impacts of disturbance on animal population size, extinction risk and species richness. However, individual responses, such as changes in body condition, can act as more sensitive metrics and may provide early warning signs of reduced fitness and population declines. We conducted the first global systematic review and meta-analysis investigating the impacts of ecosystem disturbance on reptile and amphibian body condition. We collated 384 effect sizes representing 137 species from 133 studies. We tested how disturbance type, species traits, biome and taxon moderate the impacts of disturbance on body condition. We found an overall negative effect of disturbance on herpetofauna body condition (Hedges' g = −0.37, 95% CI: −0.57, −0.18). Disturbance type was an influential predictor of body condition response and all disturbance types had a negative mean effect. Drought, invasive species and agriculture had the largest effects. The impact of disturbance varied in strength and direction across biomes, with the largest negative effects found within Mediterranean and temperate biomes. In contrast, taxon, body size, habitat specialisation and conservation status were not influential predictors of disturbance effects. Our findings reveal the widespread effects of disturbance on herpetofauna body condition and highlight the potential role of individual-level response metrics in enhancing wildlife monitoring. The use of individual response metrics alongside population and community metrics would deepen our understanding of disturbance impacts by revealing both early impacts and chronic effects within affected populations. This could enable early and more informed conservation management.     

Identification methods and deterministic factors of owl roadkill hotspot locations in Mediterranean landscapes

Road fatalities are among the major causes of mortality for Strigiformes species and may affect the population’s survival. The use of mitigation strategies must be considered to overcome this problem. However, because mitigation along the total length of all roads is not financially feasible, the locations where Strigiformes roadkills are more frequent (i.e., road fatality hotspots) must be identified. In addition to hotspot identification, factors that influence the occurrence of such fatalities should be recognized to allow mitigation measures to be delineated. We used road fatality data collected from 311 km of southern Portugal roads over a 2-year period to compare the performance of five hotspot identification methods: binary logistic regression (BLR), ecological niche factor analysis (ENFA), Kernel density estimation, nearest neighbor hierarchical clustering (NNHC), and Malo’s method. BLR and ENFA modelling were also used for recognizing roadkill deterministic factors. Our results suggest that Malo’s method should be preferred for hotspot identification. The main factors driving owl roadkillings are those associated with good habitat conditions for species occurrence and specific conditions that promote hunting behavior near roads. Based on these factors, several mitigation measures are recommended.     

Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar

We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar''s reptile species might also be threatened by disease. Standardized population monitoring of key amphibian and reptile species should be established with urgency to enable early detection of potential impacts of disease emergence in this global biodiversity hotspot.     

A note on amphibian decline in a central Amazonian lowland forest

The massive reductions in amphibian populations taking place across the globe are unprecedented in modern times. Within the Neotropics, the enigmatic decline of amphibians has been considered predominantly a montane phenomenon; however, recent evidence suggests amphibian and reptile populations in lowland forests in Central America are waning as well. Unfortunately, very little baseline data are available for conducting large scale time series studies in order to further investigate and confirm declines in the lowland forests of tropical America. Here we compare leaf litter herpetofauna abundance at sites in the Central Amazon, sampled first in 1984–1985 and again in 2007. We find no evidence for a decline in abundance or biomass of amphibians over a period of 22 years at this site. This conclusion differs markedly from the decline of 75% in amphibian populations over 35 years at a lowland site in Costa Rica. To explore potential declines in lowland Neotropical amphibian populations in detail, we suggest that existing baseline data be comprehensively compiled and analyzed for previously sampled sites and that these sites be re-sampled using comparable methodologies.