A global reptile assessment highlights shared conservation needs of tetrapods.

Comprehensive assessments of species' extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4-7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened-confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods-agriculture, logging, urban development and invasive species-although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles-including most species of crocodiles and turtles-require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.

AmphiBIO, a global database for amphibian ecological traits.

Current ecological and evolutionary research are increasingly moving from species- to trait-based approaches because traits provide a stronger link to organism's function and fitness. Trait databases covering a large number of species are becoming available, but such data remains scarce for certain groups. Amphibians are among the most diverse vertebrate groups on Earth, and constitute an abundant component of major terrestrial and freshwater ecosystems. They are also facing rapid population declines worldwide, which is likely to affect trait composition in local communities, thereby impacting ecosystem processes and services. In this context, we introduce AmphiBIO, a comprehensive database of natural history traits for amphibians worldwide. The database releases information on 17 traits related to ecology, morphology and reproduction features of amphibians. We compiled data from more than 1,500 literature sources, and for more than 6,500 species of all orders (Anura, Caudata and Gymnophiona), 61 families and 531 genera. This database has the potential to allow unprecedented large-scale analyses in ecology, evolution, and conservation of amphibians.

Spatial and temporal distribution and microhabitat use of aquatic breeding amphibians (Anura) in a seasonally dry tropical forest in Chamela, Mexico / Distribución espacial y temporal y uso de microhábitat de los anuros con reproducción acuática en un bosque seco estacional en Chamela, México

Abstract: The distribution of amphibians is affected by abiotic and biotic factors, availability of resources and the characteristics of reproductive sites. In particular, reproductive activity of aquatic-breeding anurans that inhabit tropical dry areas is affected by rainfall, which determines the availability and quality of reproductive sites. In this study, we analyzed the spatial and temporal distribution of anurans with indirect development in a tropical dry forest in Western Mexico, during two rainy seasons (July 10-October 4, 2013, and June 26-September 26, 2014). We collected data on the occupancy and reproductive activity of 15 species in four temporary streams, and evaluated their relationship with precipitation, humidity and temperature. We determined richness, abundance and diversity of species in each stream; we also identified differences in the reproductive strategies and microhabitats used by the species. The most abundant species were: Tlalocohyla smithii and Exerodonta smaragdina, whereas the least abundant were Leptodactylus melanonotus and Incilius mazatlanensis. Species richness, abundance and reproductive activity peaked alongside the stream with the greatest number of breeding sites (e.g. pools). We found temporal segregation in the occupancy and reproductive activity of species in all streams which were mainly associated with precipitation. However, occupancy and reproductive activity of some species overlapped up to four weeks during part of the breeding season. Most species used specific substrates for particular reproductive activities (e.g. oviposition), but used a range of microhabitats (leaf-litter, water, rocks, branches, leaves, logs, etc.) for others (e.g. calling). We discuss these behavioral differences as factors that facilitate coexistence of species in this environment in the rainy season. Rev. Biol. Trop. 65 (3): 1082-1094. Epub 2017 September 01.

Resumen: La distribución de los anfibios se ve afectada por factores bióticos y abióticos, la disponibilidad de recursos y las características de los sitios de reproducción. En particular, la actividad reproductiva de los anuros que habitan las zonas tropicales secas se ve afectada por las lluvias, que determinan la disponibilidad y calidad de los sitios de reproducción. En este estudio, se analizó la distribución espacial y temporal de los anuros en un bosque tropical seco en el oeste de México durante dos temporadas de lluvias (10 de julio- 4 de octubre 2013 y 26 de junio- 26 de septiembre 2014). Se tomaron datos sobre la presencia de 15 especies de anuros con reproducción acuática en cuatro arroyos temporales y su relación con la precipitación, la humedad y la temperatura. Se determinó la riqueza, abundancia y diversidad de especies en cada arroyo; así como, las diferencias en las estrategias de reproducción y el uso de microhábitats por cada especie. Las especies más abundantes fueron: Tlalocohyla smithii y Exerodonta smaragdina, mientras que las menos abundantes fueron Leptodactylus melanonotus e Incilius mazatlanensis. La mayor riqueza, abundancia y actividad reproductiva se registró en el arroyo con el mayor número de sitios para la reproducción (charcas). Encontramos una segregación temporal en la presencia y actividad reproductiva de las especies que se asoció principalmente con la precipitación. También se observó una superposición de especies en algunas semanas durante la temporada de lluvias. La mayoría de las especies utilizaron sustratos específicos para determinadas actividades (por ejemplo, puesta de huevos), pero utilizaron una variedad de microhábitats para otras actividades (por ejemplo, vocalización). Discutimos estas diferencias de comportamiento como factores que facilitan la coexistencia de estas especies de anuros en este ambiente durante la estación lluviosa.

Countryside biogeography of Neotropical reptiles and amphibians.

The future of biodiversity and ecosystem services depends largely on the capacity of human-dominated ecosystems to support them, yet this capacity remains largely unknown. Using the framework of countryside biogeography, and working in the Las Cruces system of Coto Brus, Costa Rica, we assessed reptile and amphibian assemblages within four habitats that typify much of the Neotropics: sun coffee plantations (12 sites), pasture (12 sites), remnant forest elements (12 sites), and a larger, contiguous protected forest (3 sites in one forest). Through analysis of 1678 captures of 67 species, we draw four primary conclusions. First, we found that the majority of reptile (60%) and amphibian (70%) species in this study used an array of habitat types, including coffee plantations and actively grazed pastures. Second, we found that coffee plantations and pastures hosted rich, albeit different and less dense, reptile and amphibian biodiversity relative to the 326-ha Las Cruces Forest Reserve and neighboring forest elements. Third, we found that the small ribbons of "countryside forest elements" weaving through farmland collectively increased the effective size of a 326-ha local forest reserve 16-fold for reptiles and 14-fold for amphibians within our 236-km2 study area. Therefore, countryside forest elements, often too small for most remote sensing techniques to identify, are contributing -95% of the available habitat for forest-dependent reptiles and amphibians in our largely human-dominated study region. Fourth, we found large and pond-reproducing amphibians to prefer human-made habitats, whereas small, stream-reproducing, and directly developing species are more dependent on forest elements. Our investigation demonstrates that tropical farming landscapes can support substantial reptile and amphibian biodiversity. Our approach provides a framework for estimating the conservation value of the complex working landscapes that constitute roughly half of the global land surface, and which are experiencing intensification pressure worldwide.

Rapid decline of a grassland system and its ecological and conservation implications.

One of the most important conservation issues in ecology is the imperiled state of grassland ecosystems worldwide due to land conversion, desertification, and the loss of native populations and species. The Janos region of northwestern Mexico maintains one of the largest remaining black-tailed prairie dog (Cynomys ludovicianus) colony complexes in North America and supports a high diversity of threatened and endangered species. Yet, cattle grazing, agriculture, and drought have greatly impacted the region. We evaluated the impact of human activities on the Janos grasslands, comparing changes in the vertebrate community over the last two decades. Our results reveal profound, rapid changes in the Janos grassland community, demonstrating large declines in vertebrate abundance across all taxonomic groups. We also found that the 55,000 ha prairie dog colony complex has declined by 73% since 1988. The prairie dog complex has become increasingly fragmented, and their densities have shown a precipitous decline over the years, from an average density of 25 per ha in 1988 to 2 per ha in 2004. We demonstrated that prairie dogs strongly suppressed woody plant encroachment as well as created open grassland habitat by clearing woody vegetation, and found rapid invasion of shrubland once the prairie dogs disappeared from the grasslands. Comparison of grasslands and shrublands showed markedly different species compositions, with species richness being greatest when both habitats were considered together. Our data demonstrate the rapid decline of a grassland ecosystem, and documents the dramatic loss in biodiversity over a very short time period concomitant with anthropogenic grassland degradation and the decline of a keystone species.

Chytridiomycosis survey in wild and captive mexican amphibians.

Mexico, a rich country in terms of amphibian diversity, hosts about 375 described species. Population declines have been documented for several species where it is evident that their habitat is being destroyed or modified. However, other species which inhabit pristine areas are declining as well. It has been suggested that the chytrid fungus Batrachochytrium dendrobatidis (B.d.) may be one of the causes of the enigmatic declines in Mexico. We surveyed a total of 45 localities, in 12 states across Mexico, examining a total of 360 specimens representing 14 genera and 30 species. We also examined 91 specimens of Ambystoma mexicanum from a captive population in Mexico City as well as one Pachymedusa dacnicolor obtained in a pet shop. We used a two-tiered technique to detect the pathogen. For wild-caught specimens, we utilized light microscopy to identify presence of B.d. sporangia in amphibian skin. Then, to verify the infection, we used a quantitative real-time PCR assay on collected skin sections which is specific for B.d. For captive animals, we used a nonlethal version of the real-time PCR technique. We found evidence of B.d. infection in 111 animals comprising 14 species in 13 localities. A large percentage (84%) of Ambystoma mexicanum from the colony were infected with B.d. The two most highly infected individuals were the endangered Ambystoma mexicanum, from a captive colony, and Pachymedusa dacnicolor, purchased at a pet shop.

Diversity, natural history and conservation of amphibians and reptiles from the San Vito Region, southwestern Costa Rica

We present an inventory of the amphibians and reptiles of the San Vito de Coto Brus region, including the Las Cruces Biological Station, in southern Costa Rica, which is the result of a survey of the herpetofauna occurring in mountain forest fragments, pastures, coffee plantations, and other disturbed areas. We found 67 species, included 26 species of amphibians and of 41of reptiles. We describe the distribution patterns of the community on the basis of the life zones, elevation, fragmentation, and degree of anthropogenic impact. We also provide some nouvelle data on the systematics of some select taxa, their geographical ranges, microhabitats, activity, and other relevant ecological and natural history features. Finally, we comment on the present conservation status of the herpetofauna in the region. Previous literature and collection records indicate a higher number of species occurring in this area, which suggests that some declines have occurred, especially of amphibians, in last decades. Rev. Biol. Trop. 56 (2): 755-778. Epub 2008 June 30.

En este artículo se presenta un inventario de los anfibios y reptiles de la región de San Vito de Coto Brus incluyendo la Estación de Biología Las Cruces, en el sur de Costa Rica. Se llevó a cabo una evaluación de las poblaciones de anfibios y reptiles presentes en los parches de bosque, potreros, cafetales y otras áreas perturbadas de la región. Como resultado de esta evaluación se registraron 26 especies de anfibios y 41 de reptiles lo que suma un total de 67 especies. Asimismo se describen los patrones generales de distribución de las especies basándose en los tipos de vegetación así como en la altitud, fragmentación y grado de perturbación antrópica en el área. Se proporcionan algunos datos sobre la sistemática de las especies, su distribución geográfica, el microhábitat que ocupan, su actividad y otros datos ecológicos y biológicos relevantes. Finalmente, se presenta una breve discusión sobre la conservación de la herpetofauna en la región. Algunos registros de la literatura y de colecciones científicas muestran que el número de especies de la herpetofauna conocidos en esta región era probablemente mayor, lo que podría indicar que han ocurrido algunas declinaciones importantes de especies, especialmente de anfibios en las últimas décadas.

Diversity, natural history and conservation of amphibians and reptiles from the San Vito Region, southwestern Costa Rica.

We present an inventory of the amphibians and reptiles of the San Vito de Coto Brus region, including the Las Cruces Biological Station, in southern Costa Rica, which is the result of a survey of the herpetofauna occurring in mountain forest fragments, pastures, coffee plantations, and other disturbed areas. We found 67 species, included 26 species of amphibians and of 41 of reptiles. We describe the distribution patterns of the community on the basis of the life zones, elevation, fragmentation, and degree of anthropogenic impact. We also provide some nouvelle data on the systematics of some select taxa, their geographical ranges, microhabitats, activity, and other relevant ecological and natural history features. Finally, we comment on the present conservation status of the herpetofauna in the region. Previous literature and collection records indicate a higher number of species occurring in this area, which suggests that some declines have occurred, especially of amphibians, in last decades.