DOI: 10.3897/natureconservation.64.183777

Authors: Wenlong Qi, Jianxiong Li, Cheng Qin, Lei Xie, Shuran Li, Yongpu Zhang

Abstract: The theory of island biogeography posits that geographical features play a key regulatory role in shaping biodiversity. As a dispersal-limited group, amphibians are particularly sensitive to island effects. To clarify the community structure characteristics of amphibians on the coastal islands of southern Zhejiang and identify their influencing factors, this study analyzed survey data collected from October 2021 to July 2025. Integrating island geographic characteristics and land cover data, cluster analysis, redundancy analysis, machine learning models, and SHapley Additive exPlanations (SHAP) were employed to elucidate the driving mechanisms behind community structure. The results indicated that a total of nine amphibian species from five families and one order were recorded across 36 islands. Duttaphrynus melanostictus, Fejervarya multistriata, and Hylarana guentheri were identified as the dominant species, showing significant distribution correlations (P < 0.05). The Shannon-Wiener index was highest on Dongtou Island, Damen Island, Lingkun Island, and Nanji Island. Cluster analysis based on community similarity using the elbow method grouped the islands into two categories. Human activities, along with the proportions of agricultural land and freshwater cover, significantly influenced the current amphibian community structure. The XGBoost model demonstrated the highest goodness of fit for diversity indices and exhibited optimal prediction stability. SHAP analysis identified land area (ARE), shape index (SAI), and distance to the nearest mainland (MID) as key driving factors: ARE had a strong positive effect on island biodiversity, whereas an increase in SAI promoted diversity on small islands. An increase in MID generally reduced diversity on small islands but enhanced it on larger islands. This study quantifies the differential regulatory mechanisms of island geographic features and provides a basis for formulating biodiversity conservation strategies for coastal islands.

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DOI: 10.3897/natureconservation.63.163964

Authors: Rosa Laura Heredia-Bobadilla, Javier Manjarrez, Aldo Gómez-Benítez, Erika Adriana Reyes-Velázquez, Juan Manuel Carmen-Cristobal, Alexis Josué Sánchez-Lara, Germán Martínez-Alva, René Bolom-Huet, Armando Sunny

Abstract: Amphibians are amongst the most threatened vertebrate groups worldwide and population declines are driven by climate change, habitat degradation and the spread of emerging infectious diseases. One of the most devastating pathogens is Batrachochytrium dendrobatidis (Bd), the causative agent of chytridiomycosis. In Mexico – a global hotspot of amphibian diversity and endemism – Bd has been reported in numerous taxa. However, studies addressing the potential distribution and ecological niche overlap of this species with native amphibians are limited. In this study, we modelled the potential distribution of Bd alongside 13 amphibian species from three families: Hylidae, Ambystomatidae and Plethodontidae. Species were selected, based on their conservation status, endemicity and data availability, particularly for Pseudoeurycea, which remains poorly studied beyond presence records. Ecological niche models (ENMs) and niche overlap analyses revealed extensive spatial congruence between Bd and amphibian distributions, especially within the Trans-Mexican Volcanic Belt and Sierra Madre del Sur — regions already recognised as amphibian biodiversity hotspots. Our findings highlight the high environmental suitability of these plants for both Bd and amphibians and reveal critical areas where the risk of disease transmission may increase. These findings emphasise the urgency of implementing targeted conservation actions, including long-term monitoring, early detection of infections, identification of resistant or tolerant populations and regulation of ecotourism in vulnerable regions. Mapping zones of overlap provide valuable guidance for prioritising areas for disease mitigation and habitat protection, particularly for endangered and endemic amphibian species. Our study offers novel insights into the spatial dynamics of Bd in Mexico and contributes to the development of proactive strategies for amphibian conservation.

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DOI: 10.3897/natureconservation.63.183849

Authors: Xiaoli Zhang, Amaël Borzée, Sumbul Gill, Siti N. Othman

Abstract: Amphibian misidentification within the commercial wildlife trade represents a growing challenge for biodiversity conservation and wildlife regulation. Morphologically similar species are frequently traded under incorrect names, which can obscure conservation status, facilitate illegal trade, and mislead consumers. We purchased four specimens advertised as Hoplobatrachus chinensis, a widespread farmed species, from an online marketplace in China. Because of their unexpected morphology upon reception, we barcoded them with a widely used tyrosinase (TYR) gene marker. We reconstructed a Bayesian inference-based phylogeny using a final dataset consisting of 572 bp from 51 homologous TYR sequences. The resulting tree clustered all four samples within the Quasipaa spinosa clade with high posterior probabilities (>0.99), rather than H. chinensis as advertised. This finding indicates that a protected species has been misidentified and traded despite China’s wildlife trade regulations. The case underscores the urgent need for accurate taxonomic identification tools for traders to prevent such misidentifications and stricter amphibian trade regulations to curb the ongoing illegal trade of threatened taxa.

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DOI: 10.3897/natureconservation.63.174035

Authors: Duong Thuy Thi Le, Thinh Gia Tran, Anh Phuong Tran Do, Hung Manh Pham

Abstract: Ophryophryne gerti, an endangered toad endemic to the Langbian Plateau, Vietnam, has been known only from a restricted range in Bidoup Nui Ba and Chu Yang Sin National Parks. The conservation and sustainability of the species require knowledge of its true distribution, life history, and genetic diversity. During field surveys from July 2022 to September 2023 on the Di Linh Plateau, the southernmost extent of the Truong Son Range, adult and tadpole specimens of O. gerti were collected. A 940 bp fragment of the mitochondrial 12S rRNA–16S rRNA region was sequenced for phylogenetic and population genetic analyses. Our findings extend the species’ known range approximately 66 km southward, documenting its presence at lower elevations (500–2000 m). Tadpoles of O. gerti are characterized by an oval, depressed body; dorsolateral eyes; sinistral spiracle; pointed tail tip; and keratodont-free oral disc with serrated jaw sheaths. Phylogenetic analyses confirmed that the newly collected Di Linh specimens belong to O. gerti, which is closely related to O. synoria. Ten haplotypes were detected across populations, with Di Linh showing higher haplotype diversity (Hd = 0.993) but slightly lower nucleotide diversity (π = 0.00465) than Bidoup–Chu Yang Sin (Hd = 0.791; π = 0.00485). Both genetic indices and neutrality tests revealed that populations of this species are threatened in the wild, including Di Linh and well-protected areas such as Bidoup–Nui Ba and Chu Yang Sin National Parks. The Di Linh populations carried excess rare variation or low-frequency polymorphisms due to habitat fragmentation. These results highlight the Di Linh Plateau as an important conservation unit for O. gerti and emphasize the need to protect fragmented forest habitats to preserve the species’ genetic diversity and adaptive potential.

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DOI: 10.3897/natureconservation.61.148493

Authors: Pablo Nascimento Martins, Erica Naomi Saito, Felipe Moreli Fantacini, André Ambrozio-Assis, Eduardo Araujo da Silva, André Luiz Ferreira da Silva, Guilherme Augusto Munhoz de Sá, Márcio Vieira de Carvalho Junior, Rodrigo Sidoski, José Roberto Nascimento da Costa, Marcelo Gordo, Clarissa Rosa

Abstract: Roads greatly impact wildlife, with roadkill posing a major threat to many species. In the Amazon, highways cut through biodiversity-rich ecosystems, exposing mammals, birds, reptiles, and amphibians to roadkill risks. Increasing traffic and expanding road networks drive population declines, influenced by environmental traits, traffic, and seasonal conditions. Temporal variation in these conditions can lead to shifting roadkill patterns over time, making it essential to understand how such changes affect wildlife mortality. Our study aims to identify temporal variation on roadkill hotspots and investigate their relationship with climatic (temperature and rainfall) and landscape (forest, agricultural, and wetland cover) factors. We used a roadkill database from the first 177.8 km of BR-319 (Manaus – Porto Velho) spanning 2017 to 2021 to evaluate variations in hotspots over time and investigate how those climate and landscape factors affect roadkills across different buffers (500 m, 1 km, 5 km, and 10 km). We recorded 673 roadkill incidents (107 mammals, 251 reptiles, 152 birds, and 163 amphibians). Hotspot patterns varied across years, with amphibians, reptiles, birds, and mammals showing distinct hotspot patterns. Climate and landscape factors significantly influenced roadkill rates, with higher temperatures correlating with more roadkill, while rainfall generally decreased incidents, and increased forest and water cover helped reduce roadkill across most groups. Our findings suggest that both climatic and landscape factors play crucial roles in shaping roadkill patterns, reinforcing the need to monitor changes over time and highlighting the need for context-specific conservation strategies along highways. In conclusion, mitigating roadkill along BR-319 will require integrated approaches that consider environmental variables, traffic management, and habitat protection to reduce wildlife mortality.

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DOI: 10.3897/natureconservation.58.140853

Authors: Julio A. Lemos-Espinal, Geoffrey R. Smith

Abstract: The Sierra Madre del Sur (SMS) is a biologically diverse biogeographic province found in south-central Mexico. It is therefore an area of interest from a conservation standpoint. Here we examine the diversity and conservation status of the amphibians and reptiles of the SMS and its subprovinces and determine their similarity with neighboring provinces. We compiled a list of the species of amphibians and reptiles occurring in the SMS and its neighboring provinces from the available literature and gathered information on their conservation status. We also compiled the herpetofauna of the three subprovinces of the SMS (Western, Central, and Eastern). The SMS houses 186 species of amphibians, of which 89% are endemic to Mexico and 53% endemic to the SMS. The SMS also contains 331 reptile species, of which 72% are endemic to Mexico and 23% are endemic to the SMS. The amphibian and reptile diversity of the SMS is concentrated in the Eastern subprovince. The significant number of amphibian and reptile species endemic to the SMS highlights its importance for conservation. Comparison with neighboring provinces shows that the SMS shares 33% of its species with the Transvolcanic Belt, 25% with the Pacific Lowlands and Balsas Basin, and 19% with Veracruzan. The SMS shares 52% of its reptile species with the Transvolcanic Belt, 42% with the Pacific Lowlands, 40% with the Balsas Basin, and 33% with the Veracruzan. The results of a cluster analyses suggest that the SMS does not represent a single unit in terms of its herpetofauna, since the three subprovinces do not cluster together. The Western and Central subprovinces cluster with the Balsas Basin and the Pacific Lowlands, whereas the Eastern subprovince clusters separately. We found that 25.7% of the evaluated amphibian and reptile species in the SMS are included in the International Union for Conservation of Nature’s (IUCN) Red List in some category of conservation concern (amphibians: 54.9%; reptiles: 6.8%). The Eastern subprovince hosts the highest proportion of species of conservation concern (93.8%). It is important to increase the number of areas protected by federal and state governments, especially in the Eastern subprovince, and to promote protections driven by local communities. These actions could help protect the herpetofauna of the SMS, especially the Eastern subprovince, which harbors a unique fauna and deserves special consideration from a conservation standpoint.

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DOI: 10.3897/natureconservation.58.137848

Authors: Klaus Henle, Reinhard A. Klenke, M. Benjamin Barth, Annegret Grimm-Seyfarth, Diana E. Bowler

Abstract: Over the last decades, the worldwide decline of amphibian populations has become a major concern of researchers and conservationists. Studies have reported a diversity of trends, with some species strongly declining, others remaining stable and still others increasing. However, only a few species have been monitored annually for a long period of time by specific monitoring programmes. Instead, there are many heterogeneous datasets that contain observations of amphibians from professional surveys as well as diverse citizen science and other voluntary surveys. The use of these data brings a number of challenges, raising concerns about their validity and use in ecological research and conservation. We assessed to what extent such heterogeneous occurrence data can provide information on the status and trends of amphibians by contrasting different approaches to overcoming challenges with the data, using the German state of Saxony as an example. We assessed the effects of data processing decisions to infer absences, the use of survey method information and the statistical model (generalised linear mixed-effect occurrence model [GLMM] versus occupancy-detection model) and compared the trends with expert opinions (Red Lists). The different data processing decisions mainly led to similar annual occupancy estimates, newts being an exception. Annual occupancy estimates were typically less certain when attempting to account for the effects of survey methods, which could be explained by many missing values on methods. Separate models for drift fence data reduced the uncertainty in the annual occurrence probability estimates of the GLMM models, but uncertainty remained high for occupancy-detection models. For both methods, strong peaks and troughs in the annual occupancy estimates occurred for several species, which were not biologically plausible. Some peaks align with periods of lower sampling effort and were probably caused by shifts in the sampling locations or target species amongst years. Only for three species (Bufotes viridis, Hyla arborea and Pelophylax esculentus) were the trend results consistent amongst approaches and with expert opinions. For most other species, some inconsistencies appeared amongst models or approaches, indicating that trend assessments are sensitive to analytical choices. While heterogeneous data have proved useful for other taxa, our results highlight the complexity of using them for amphibians. We strongly recommend better harmonisation of data collection and metadata documentation, including explicit absence data and, if available, abundance data, to enable more robust trend assessments in the future.

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DOI: 10.3897/natureconservation.56.125561

Authors: Julio A. Lemos-Espinal, Geoffrey R. Smith

Abstract: The Transvolcanic Belt (TVB) of Mexico is a biogeographic province of significant biodiversity, acting as a transition zone between eastern and western Mexico. Using available literature, we collected species lists for amphibians and reptiles in Mexican states within the TVB biogeographic province, updating them with additional literature. The TVB is home to 427 native species of amphibians and reptiles, 154 amphibians and 273 reptiles, which represent 30.5% of the species of amphibians and reptiles in Mexico. The TVB also houses 50 endemic species, with 84 species listed by the IUCN. Threats include habitat destruction and pollution. The TVB shares a significant portion of its amphibian and reptile species with neighboring provinces, particularly the Sierra Madre Oriental and the Sierra Madre del Sur, suggesting a mixture of species from both eastern and western Mexico. Cluster analyses based on species composition reveal distinct groupings of provinces, with the TVB forming a cluster with the Sierra Madre Oriental, Veracruzan, and Sierra Madre del Sur for both amphibians and reptiles. Conservation assessments indicate that a significant proportion of the amphibian and reptile species in the TVB are at risk, primarily due to habitat loss from urbanization, agriculture, and pollution. Urgent conservation actions are needed to protect the unique herpetofauna of the TVB from further decline.

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DOI: 10.3897/natureconservation.53.106732

Authors: Julio A. Lemos-Espinal, Geoffrey R. Smith

Abstract: Mexico is a megadiverse country with high amphibian and reptile richness. Understanding how Mexico’s herpetofauna is shared among Mexican states can contribute to developing conservation plans by figuring out which states may need to coordinate conservation actions. We generated species lists for the herpetofauna for all Mexican states, and used hierarchical clustering analyses to identify clusters of states on the basis of amphibian and reptile species separately. We also calculated pair-wise Jaccard distances for all Mexican states for amphibians, reptiles, and physiographic provinces and estimated the length of shared borders between states and the geographic (straight-line) distance between the centroids of pairs of states. We used these data to explore potential drivers of the cluster analysis results. Our cluster analysis for amphibians identified five clusters with nine subclusters, and for reptiles, resulted in four clusters with six subclusters. In general, the clusters for Mexican amphibians and reptiles have a similar composition of states. However, for amphibians, the states of Veracruz and Puebla form a cluster separate from a large cluster of northeastern Mexican states, whereas in reptiles Veracruz and Puebla cluster with northeastern Mexican states. Jaccard distances of amphibians and reptiles were highly, positively correlated. Both amphibian and reptile Jaccard distances were positively correlated with the physiographic provinces’ Jaccard distance and shared border length and negatively correlated with the distance between centroids. Taken together, our results suggest that the pattern of the sharing of herpetofaunal species among Mexican states is a consequence of the states’ proximity. Such a pattern is consistent with the underlying driver being the similarity of physiographic provinces (i.e., habitats and ecosystems) of these states (i.e., geographic proximity likely reflects, at least in large part, ecological similarity). Our results suggest clusters of states that should coordinate the conservation and management of their herpetofaunas. For example, clusters of states in southern Mexico share a high number of threatened amphibian species and clusters of states in northern Mexico share a high number of threatened reptile species. Oaxaca is also a state that has a unique herpetofauna and a high number of threatened species of both amphibians and reptiles.

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DOI: 10.3897/natureconservation.51.93868

Authors: Mark Auliya, Sandra Altherr, Charlotte Nithart, Alice Hughes, David Bickford

Abstract: The commercial trade in frogs and their body parts is global, dynamic and occurs in extremely large volumes (in the thousands of tonnes/yr or billions of frogs/yr). The European Union (EU) remains the single largest importer of frogs’ legs, with most frogs still caught from the wild. Amongst the many drivers of species extinction or population decline (e.g. due to habitat loss, climate change, disease etc.), overexploitation is becoming increasingly more prominent. Due to global declines and extinctions, new attention is being focused on these markets, in part to try to ensure sustainability. While the trade is plagued by daunting realities of data deficiency and uncertainty and the conflicts of commercial interests associated with these data, it is clear is that EU countries are most responsible for the largest portion of the international trade in frogs’ legs of wild species. Over decades of exploitation, the EU imports have contributed to a decline in wild frog populations in an increasing number of supplying countries, such as India and Bangladesh, as well as Indonesia, Turkey and Albania more recently. However, there have been no concerted attempts by the EU and present export countries to ensure sustainability of this trade. Further work is needed to validate species identities, secure data on wild frog populations, establish reasonable monitored harvest/export quotas and disease surveillance and ensure data integrity, quality and security standards for frog farms. Herein, we call upon those countries and their representative governments to assume responsibility for the sustainability of the trade. The EU should take immediate action to channel all imports through a single centralised database and list sensitive species in the Annexes of the EU Wildlife Trade Regulation. Further, listing in CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) can enforce international trade restrictions. More joint efforts are needed to improve regional monitoring schemes before the commercial trade causes irreversible extinctions of populations and species of frogs.

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DOI: 10.3897/natureconservation.50.86002

Authors: Giuseppe Martino, Andrea Chiocchio, Antonino Siclari, Daniele Canestrelli

Abstract: Amphibian biodiversity loss in recent years has exceeded that of all other groups of vertebrates. In this context, biodiversity hotspots represent priority targets for conservation in amphibian populations. However, little information is available on the distribution and conservation status of amphibian species within most biodiversity hotspots. Here, we characterized the distribution and conservation status of four threatened endemic amphibians (Bombina pachypus, Salamandra salamandra gigliolii, Salamandrina terdigitata, and Rana italica) in the Aspromonte Mountain region, a biodiversity hotspot in southern Italy where the conservation status of amphibians is almost unexplored. We conducted an intensive field survey of 507 potential breeding sites spanning over 2,326 km2. We found that all four species were widespread in the study area. We observed 337 species occurrences: 63 for S. s. gigliolii, 29 for S. terdigitata, 84 for B. pachypus, and 161 for R. italica. Species distribution analysis revealed that S. s. gigliolii and R. italica populations had an extended and homogenous distribution. Conversely, S. terdigitata showed a dispersed pattern, with long distances among breeding sites, and B. pachypus an aggregated pattern, associated with the availability of suitable artificial habitats. On the other hand, we reported a decrease in B. pachypus occurrence in its natural habitats, which reflects a negative trend of its populations. Overall, our results provide an encouraging framework for the conservation of amphibian populations in this area, but highlight the low coverage of threatened amphibian populations in protected areas, highlighting the need for a reassessment of conservation policies and spatial conservation planning for the Aspromonte region.

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DOI: 10.3897/natureconservation.49.82931

Authors: Dario Nania, Maria Lumbierres, Gentile Francesco Ficetola, Mattia Falaschi, Michela Pacifici, Carlo Rondinini

Abstract: Planning conservation actions requires detailed information on species’ geographic distribution. Species distribution data are most needed in areas hosting unique or endangered biodiversity. Italy is one of the European countries with the highest levels of herpetological diversity and endemism and is home to several threatened species of amphibians and reptiles. Information on the distribution of species’ habitats can help identify sites where the species is most likely to thrive, as viable populations depend on it. Area of Habitat (AOH) maps reveal the distribution of the habitat available to the species within their geographic range. We produced high resolution, freely accessible global area of habitat maps for 60 species of reptiles and amphibians distributed in Italy, which represent 60% of all Italian amphibian and reptile species. We validated a total of 44 AOH maps through a presence-only based evaluation method, with 86% of these maps showing a performance better than expected by chance. AOH maps can be used as a reference for conservation planning, as well as to investigate macroecological patterns of Italian herpetofauna. Furthermore, AOH maps can help monitoring habitat loss, which is known to be a major threat to many reptile and amphibian species in Europe.

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DOI: 10.3897/natureconservation.49.82145

Authors: Marie Krzikowski, Truong Q. Nguyen, Cuong T. Pham, Dennis Rödder, Anna Rauhaus, Minh D. Le, Thomas Ziegler

Abstract: The current decline in global biodiversity is most evident in amphibians with 41% percent of all species worldwide classified as threatened with extinction. Hence, a major challenge in amphibian conservation is the high number of threatened species, leading to a common approach of identifying priority species and regions for conservation efforts. As a part of one of 36 globally designated biodiversity hotspots, Vietnam is considered to be of particular importance for conservation action. To improve amphibian conservation in Vietnam, this study provides an updated species list and assesses their threat status by compiling data from a variety of sources. Furthermore, a Zoological Information Management System (ZIMS) analysis was conducted to determine the representation of extant amphibians from Vietnam in zoos worldwide. The batrachofauna of Vietnam is characterized by a high level of species richness and local endemism as well as a high rate of new discoveries, with more than half of the endemic species reported exclusively from their type locality, making them especially vulnerable to extinction. Up to 18% of all amphibians extant in Vietnam and 28% of endemic species are classified as threatened with extinction by the IUCN. In many cases, the IUCN Red List status is either missing or outdated, highlighting the urgent need of action. Around 14% of endemic amphibian species have been recorded exclusively from unprotected areas, suggesting prioritization for further research and conservation measures. The continuing decline in many species remains an unresolved problem. As a guide for future research and conservation measures, a list of the top 57 species was compiled. In addition, according to the ZIMS analysis, only 8% of threatened and 3% of endemic amphibian taxa from Vietnam are currently kept in zoos worldwide, and a richness analysis revealed that the highest density of husbandries is found in Europe and North America. To achieve maximum outcome for the conservation of threatened species, this study recommends a general shift by zoos towards maintaining species in greater need of captive assurance populations and breeding programs to support integrative strategies that combine in situ and ex situ conservation efforts following the IUCN’s One Plan Approach.

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DOI: 10.3897/natureconservation.47.71472

Authors: Antonin Conan, Julie Fleitz, Lorène Garnier, Meven Le Brishoual, Yves Handrich, Jonathan Jumeau

Abstract: Transport infrastructures, such as highways, disrupt animal migrations and cause roadkill. To mitigate the latter problem, fences have been built but their effectiveness has rarely been tested under controlled conditions. Here, we tested the effectiveness of the most commonly used fence in France and probably in Europe (wire netting fence) to block animals. We tested the wire netting fence, with and without a structural modification (i.e. an overhang), with three small mammalian species (the European hamster: Cricetus cricetus Linnaeus, 1758; the common vole: Microtus arvalis Pallas, 1778 & the wood mouse: Apodemus sylvaticus Linnaeus, 1758) and two amphibian species (the marsh frog: Pelophylax ridibundus Pallas, 1771 & the European green toad: Bufotes viridis Laurenti, 1768). During testing, all small vertebrate species tested were placed into an arena, from which they could only escape by crossing the wire netting fence. Without an overhang, almost all adult individuals of all tested species were able to climb over a 30 to 40 cm high wire netting fence. Furthermore, the addition of an 8 cm long overhang at the top of the fence stopped the amphibian species tested but not the most agile mammalian species, such as the hamster and the wood mouse. Based on these results, we do not support the construction of wire netting fences along roads as a measure to stop small animals from crossing. We recommend the use of more effective and durable fences, which, in addition, can be associated with wildlife passages to reconnect isolated populations.

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DOI: 10.3897/natureconservation.44.63270

Authors: Jeremy S. Dertien, Courtney L. Larson, Sarah E. Reed

Abstract: Outdoor recreation is increasingly recognised for its deleterious effects on wildlife individuals and populations. However, planners and natural resource managers lack robust scientific recommendations for the design of recreation infrastructure and management of recreation activities. We reviewed 38 years of research on the effect of non-consumptive recreation on wildlife to attempt to identify effect thresholds or the point at which recreation begins to exhibit behavioural or physiological change to wildlife. We found that 53 of 330 articles identified a quantitative threshold. The majority of threshold articles focused on bird or mammal species and measured the distance to people or to a trail. Threshold distances varied substantially within and amongst taxonomic groups. Threshold distances for wading and passerine birds were generally less than 100 m, whereas they were greater than 400 m for hawks and eagles. Mammal threshold distances varied widely from 50 m for small rodents to 1,000 m for large ungulates. We did not find a significant difference between threshold distances of different recreation activity groups, likely based in part on low sample size. There were large gaps in scientific literature regarding several recreation variables and taxonomic groups including amphibians, invertebrates and reptiles. Our findings exhibit the need for studies to measure continuous variables of recreation extent and magnitude, not only to detect effects of recreation on wildlife, but also to identify effect thresholds when and where recreation begins or ceases to affect wildlife. Such considerations in studies of recreation ecology could provide robust scientific recommendations for planners and natural resource managers for the design of recreation infrastructure and management of recreation activities.

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DOI: 10.3897/natureconservation.44.65528

Authors: Gabriele Dessalvi, Enrico Borgo, Loris Galli

Abstract: Wildlife recovery centres are widespread worldwide and their goal is the rehabilitation of wildlife and the subsequent release of healthy animals to appropriate habitats in the wild. The activity of the Genoese Wildlife Recovery Centre (CRAS) from 2015 to 2020 was analysed to assess its contribution to the conservation of biodiversity and to determine the main factors affecting the survival rate of the most abundant species. In particular, the analyses focused upon the cause, provenance and species of hospitalised animals, the seasonal distribution of recoveries and the outcomes of hospitalisation in the different species. In addition, an in-depth analysis of the anthropogenic causes was conducted, with a particular focus on attempts of predation by domestic animals, especially cats. Significantly, 96.8% of animals hospitalised came from Liguria, the region in north-western Italy where CRAS is located, with 44.8% coming from the most populated and urbanised areas of Genoa, indicating a positive correlation between population density and the number of recoveries. A total of 5881 wild animals belonging to 162 species were transferred to CRAS during the six years study period. The presence of summer migratory bird species and the high reproductive rates of most animals in summer resulted in a corresponding seasonal peak of treated animals. Birds represented 80.9% of entries; mammals accounted for 18.6% of hospitalisations; and about 0.5% of the entries were represented by reptiles and amphibians. Species protected by CITES and/or in IUCN Red List amounted to 8% of the total number of individuals. Consistent with results recorded elsewhere from Italy and other European countries, 53.9% of the specimens treated were released in nature; 4.7% were euthanised and 41.4% died. There was a significant difference between taxa in the frequency of individuals that were released, died or euthanised due to the intrinsic characteristics of species (more resistant or more adaptable to captivity than others) and/or to the types of debilitative occurrences common to each species (e.g. infections, wounds, traumas, fractures). A total of 14.2% of wildlife recovery was from injuries caused with certainty by people or domestic animals (human impact), with 54.3% of these hospitalised animals having been victims of predation attempts by domestic animals, mainly cats. The percentage of release in nature of animals hospitalised following human impact was significantly lower than overall cases (31.2% vs. 53.9%) due to the greater severity of the injuries. The percentage of animals released showed a further reduction to 27.1% amongst victims of predation attempts by pets. The work of Rehabilitation/Recovery Centres contributes to wildlife conservation. In particular, the CRAS in Genoa is a Centre with an increasing level of activity concerning the rehabilitation of species under CITES protection and/or included on the IUCN Red List. The contribution and experience of CRAS operators is critical for the success of ‘information campaigns’ aimed at limiting the number of stray dogs and cats because of their impact on wildlife. Therefore, the activity of a properly-managed CRAS can significantly contribute both directly and indirectly to wildlife conservation, resulting in important territorial safeguards for the protection of biodiversity.

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DOI: 10.3897/natureconservation.41.54265

Authors: Matheus Oliveira Neves, Hugo Cabral, Mariana Pedrozo, Vanda Lucia Ferreira, Mário Ribeiro Moura, Diego José Santana

Abstract: There are many gaps in our biodiversity knowledge, especially in highly diverse regions such as the Neotropics. Basic information on species occurrence and traits are scattered throughout different literature sources, which makes it difficult to access data and ultimately delays advances in ecology, evolution, and conservation biology. We provide species occurrence and trait data for amphibian species in the Upper Paraguay River Basin, central South America. The compiled information is made available through two different datasets that hold (i) 17K species occurrence records and (ii) 30 species-level traits for 113 amphibian species. The first dataset includes the species occurrence records and informs specimen id, collection of housing, locality, geographical coordinates, geographic accuracy, collection date, and collector name. The second dataset covers species-level attributes on morphometry, diet, activity, habitat, and breeding strategy. These datasets improve accessibility to spatial and trait data for amphibian species in the Pantanal ecoregion, one of the largest wetlands on Earth.

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DOI: 10.3897/natureconservation.26.25339

Authors: Henning Steinicke, Guy Pe’er, Klaus Henle

Abstract: Habitat destruction and fragmentation alter the quality of habitats and put populations under the risk of extinction. Changes in population parameters can provide early warning signs of negative impacts. In tropical forests, where habitat loss and fragmentation are vast, such indicators are of high relevance for directing conservation efforts before effects are irreversible. Most of our knowledge from tropical ecosystems originates from community level surveys, whereas our understanding of the influence of habitat conversion on vital rates of species is limited. This study focused on the influence of anthropogenic habitat fragmentation on the survival probability and abundance of three leaf-litter frog species (Rhinella ornata, Ischnocnema guentheri and I. parva) in forest patches of the Atlantic rainforest of South-east Brazil compared to a continuous forest. The species differ in their matrix tolerance: high for R. ornata and low for I. guentheri and I. parva and, thus, we examined whether their survival and abundance correspond to this classification. Ischnocnema guentheri showed highest abundances in all study sites and low mortality in the forest patches compared to the continuous forest; I. parva was encountered only in isolated fragments, with very low mortality in one isolated fragment; and the matrix tolerant species had generally low abundance and showed no clear pattern in terms of mortality in the different sites. Our counter-intuitive results show that even matrix sensitive amphibian species may show high abundance and low mortality in small forest patches. Therefore, these patches can be of high value for amphibian conservation regardless of their degree of matrix aversion. Landscape level conservation planning should not abandon small habitat patches, especially in highly fragmented tropical environments.

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DOI: 10.3897/natureconservation.21.12875

Authors: Victor H. Luja, Jesús A. López, Raciel Cruz-Elizalde, Aurelio Ramírez-Bautista

Abstract: Natural Protected Areas (NPAs) includes important species richness, and it is assumed that these are the best areas for biodiversity conservation. There are certain doubts, however, about the effectiveness of the NPAs in developing countries, where economic resources for conservation are scarce and NPAs are not monitored and managed efficiently. In the present study we assessed the species richness, diversity, abundance, and functional guilds of amphibians and reptiles inside and outside of the NPA Reserva Estatal de la Biósfera Sierra San Juan (REBSSJ), Nayarit, Mexico. Our results showed that species numbers of amphibian and reptiles were higher outside than inside the reserve, as well the individual number distributed among species, except for lizard species. Analyses of functional guilds showed that both richness and functional dispersion were greater in amphibians and reptiles outside the reserve. Likewise, outside the reserve we recorded a higher species number with some category of risk at the national level (NOM-059), international level (IUCN), and also by using the Environmental Vulnerability Score (EVS) algorithm. The results suggest that areas outside of the reserve are crucial to the maintenance of regional biodiversity, due to high complementarity with species composition inside of the reserves. These data can be used to implement conservation measures that include a new demarcation of the reserve and the consideration of surrounding areas to include a great number of species.

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DOI: 10.3897/natureconservation.13.7428

Authors: Henning Steinicke, Bernd Gruber, Annegret Grimm, Wolf-Rüdiger Grosse, Klaus Henle

Abstract: Changes in morphological traits, such as body size, body condition, and leg length, are important indicators of changes to life history or habitat quality, which can affect the performance of individuals and therefore the persistence of populations under environmental change. Only very few studies assessed the effect of fragmentation on morphological traits. The few available studies on anurans found that in landscapes with less forest cover body size decreased. Therefore, we predict that body size should also be smaller in fragments compared to continuous forest. Body condition is a further trait closely related to individual performance and thus should decline with more adverse conditions, as is expected in fragments. We tested these hypotheses using snout-vent length, body mass, body condition, and tibia length as response variables. We collected data of a habitat generalist (Rhinella ornata) and a habitat specialist (Ischnocnema guentheri), both leaf-litter amphibian species, from three sites in a fragmented landscape (two isolated and one connected site) and one site in a contiguous part of the Atlantic Forest of Southeast Brazil. In the generalist species, snout-vent-length (SVL) and body mass were significantly lower in fragments compared to the contiguous forest control, whereas tibia length and body condition did not differ among sites. In contrast, SVL, body mass, and tibia length of the specialist species did not differ among sites, but body condition was marginally different among sites, being relatively low in one but not the other isolated fragment. The results indicate that different processes affect the morphology of the two species following habitat fragmentation.

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DOI: 10.3897/natureconservation.11.4439

Authors: Diemer Vercayie, Marc Herremans

Abstract: Road networks, even in industrialized countries, become denser year after year and traffic volumes continue to increase at a steady pace. It is imperative that we monitor the impact of this trend on wildlife, but monitoring roads for flattened fauna is a time consuming effort and roadkill monitoring projects conducted up till now have been relatively small scale both in terms of time and space. This hampers the progress of road ecology analyses at the population level and at larger landscape extents. We demonstrate that citizen science projects in combination with smartphones and other new technologies allow analysis at this level and extent, and simultaneously offer more complete data for safer transportation and mitigation of roadkill hotspots. Monitoring roadkill with citizen scientists poses certain challenges regarding data quality and people management, but we show that these challenges can be addressed, which allows researchers to benefit from the many other advantages and possible applications of monitoring roadkill with citizen scientists, including raising public awareness on the matter.

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DOI: 10.3897/natureconservation.11.4438

Authors: Fraser M. Shilling, David P. Waetjen

Abstract: Highways provide commuter traffic and goods movement among regions and cities through wild, protected areas. Wildlife-vehicle collisions (WVC) can occur frequently when wildlife are present, impacting drivers and animals. Because collisions are often avoidable with constructed mitigation and reduced speeds, transportation agencies often want to know where they can act most effectively and what kinds of mitigation are cost-effective. For this study, WVC occurrences were obtained from two sources: 1) highway agencies that monitor carcass retrieval and disposal by agency maintenance staff and 2) opportunistic observations of carcasses by participants in two statewide systems, the California Roadkill Observation System (CROS; http://wildlifecrossing.net/california) and the Maine Audubon Wildlife Road Watch (MAWRW; http://wildlifecrossing.net/maine). Between September, 2009 and December 31, 2014, >33,700 independent observations of >450 vertebrate species had been recorded in these online, form-based informatics systems by >1,300 observers. We asked whether or not WVC observations collected by these extensive, volunteer-science networks could be used to inform transportation-mitigation planning. Cluster analyses of volunteer-observed WVC were performed using spatial autocorrelation tests for parts or all of 34 state highways and interstates. Statistically-significant WVC hotspots were modeled using the Getis-Ord Gi* statistic. High density locations of WVC, that were not necessarily hotspots, were also visualized. Statistically-significant hotspots were identified along ~7,900 km of highways. These hotspots are shown to vary in position from year to year. For highways with frequent deer-vehicle collisions, annual costs from collisions ranged from US$0 to >US$30,000/km. Carcass clusters from volunteer data had very little or no overlap with similar findings from agency-collected WVC data, during a different time-range. We show that both state agency-collected and volunteer-collection of WVC observations could be useful in prioritizing mitigation action at US state-scales by state transportation agencies to protect biodiversity and driver safety. Because of the spatial extent and taxonomic accuracy at which volunteer observations can be collected, these may be the most important source of data for transportation agencies to protect drivers and wildlife.

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DOI: 10.3897/natureconservation.5.4612

Authors: Maj-Britt Pontoppidan, Gösta Nachman

Abstract: An expanding network of roads and railways fragments natural habitat affecting the amount and quality of habitat and reducing connectivity between habitat patches with severe consequences for biodiversity and population persistence. To ensure an ecologically sustainable transportation system it is essential to find agreement between nature conservation and land use. However, sustainable road planning requires adequate tools for assessment, prevention and mitigation of the impacts of infrastructure. In this study, we present a spatially explicit model, SAIA (Spatial Amphibian Impact Assessment), to be used as a standardized and quantitative tool for assessing the impact of roads on pond-breeding amphibians. The model considers a landscape mosaic of breeding habitat, summer habitat and uninhabitable land. As input, we use a GIS-map of the landscape with information on land cover as well as data on observed frog populations in the survey area. The dispersal of juvenile frogs is simulated by means of individual-based modelling, while a population-based model is used for simulating population dynamics. In combination the two types of models generate output on landscape connectivity and population viability. Analyses of maps without the planned road constructions will constitute a “null-model” against which other scenarios can be compared, making it possible to assess the effect of road projects on landscape connectivity and population dynamics. Analyses and comparisons of several alternative road projects can identify the least harmful solution. The effect of mitigation measures, such as new breeding ponds and underpasses, can be evaluated by incorporating them in the maps, thereby enhancing the utility of the model as a management tool in Environmental Impact Assessments. We demonstrate how SAIA can be used to assess which management measures would be best to mitigate the effect of landscape fragmentation caused by road constructions by means of a case study dedicated to the Moor frog (Rana arvalis).

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DOI: 10.3897/natureconservation.5.4611

Authors: Maj-Britt Pontoppidan, Gösta Nachman

Abstract: An extensive and expanding infrastructural network destroys and fragments natural habitat and has detrimental effect on abundance and population viability of many amphibian species. Roads function as barriers in the landscape. They separate local populations from each other or prevent access to necessary resources. Therefore, road density and traffic intensity in a region may have severe impact on regional as well as local connectivity. Amphibians may be able to detect and avoid unsuitable habitat. Individuals’ ability to avoid roads can reduce road mortality but at the same time road avoidance behaviour, can increase the barrier effect of the road and reduce connectivity. We use an individual based model to explore how changes in road mortality and road avoidance behaviour affect local and regional connectivity in a population of Moor frogs (Rana arvalis). The results indicate that road mortality has a strong negative effect on regional connectivity, but only a small effect on local connectivity. Regional connectivity is positively affected by road avoidance and the effect becomes more pronounced as road mortality decreases. Road avoidance also has a positive effect on local connectivity. When road avoidance is total and the road functions as a 100% barrier regional connectivity is close to zero, while local connectivity exhibit very elevated values. The results suggest that roads may affect not only regional or metapopulation dynamics but also have a direct effect on local population dynamics.

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