Leticia Margarita Ochoa-Ochoa

The problem of global amphibian declines has prompted extensive research over the last three decades. Initially, the focus was on identifying and characterizing the extent of the problem, but more recently efforts have shifted to evidence‐based research designed to identify best solutions and to improve conservation outcomes. Despite extensive accumulation of knowledge on amphibian declines, there remain knowledge gaps and disconnects between science and action that hamper our ability to advance conservation efforts. Using input from participants at the ninth World Congress of Herpetology, a U.S. Geological Survey Powell Center symposium, amphibian on‐line forums for discussion, the International Union for Conservation of Nature Assisted Reproductive Technologies and Gamete Biobanking group, and respondents to a survey, we developed a list of 25 priority research questions for amphibian conservation at this stage of the Anthropocene. We identified amphibian conservation research priorities while accounting for expected tradeoffs in geographic scope, costs, and the taxonomic breadth of research needs. We aimed to solicit views from individuals rather than organizations while acknowledging inequities in participation. Emerging research priorities (i.e., those under‐represented in recently published amphibian conservation literature) were identified, and included the effects of climate change, community‐level (rather than single species‐level) drivers of declines, methodological improvements for research and monitoring, genomics, and effects of land‐use change. Improved inclusion of under‐represented members of the amphibian conservation community was also identified as a priority. These research needs represent critical knowledge gaps for amphibian conservation although filling these gaps may not be necessary for many conservation actions.

AimOur aim is to document the dimensions of current squamate reptile biodiversity in the Americas by integrating taxonomic, phylogenetic and functional data, and assessing how this may vary across phylogenetic scales. We also explore the potential underlying mechanisms that may be responsible for the observed geographical diversity patterns.LocationThe Americas.Time periodPresent.Major taxaSquamate reptiles.MethodsWe used published data on the distribution, phylogeny, and body size of squamate reptiles to document the current dimensions of their alpha diversity in the Americas. We overlapped species ranges to estimate taxonomic diversity (TD) and calculated phylogenetic diversity (PD) using mean pairwise phylogenetic distance (MPD), speciation rate (DivRate) and Faith's phylogenetic index (PD). We estimated functional diversity (FD) as trait dispersion in the multivariate space using body size and leg development data. We implemented a deconstructive macroecological approach to understand how spatial mismatches between the three facets of diversity vary across phylogenetic scales, and the potential eco‐evolutionary mechanisms driving these patterns across space.ResultsWe found a strong latitudinal gradient of TD with a large accumulation in tropical regions. PD and FD patterns were largely similar likely due to the high phylogenetic signal in the traits used, and higher values tended to be concentrated in harsh and/or heterogeneous environments. We found differences between major clades within Squamata that display contrasting geographical patterns. Several regions across the continent shared the same spatial mismatches between dimensions across clades, suggesting that similar eco‐evolutionary processes are shaping these regional reptile assemblages. However, we also found evidence that non‐mutually exclusive processes can operate differently across clades.Main conclusionsThe deconstructive approach implemented here is based on a solid macroecological framework. We can extend this to other taxonomic groups to establish whether there are particularities about how different eco‐evolutionary mechanisms shape biodiversity facets in a spatially explicit context.

Bromeliads are recognized as vital habitats for arboreal amphibians. However, these plants are often not included in traditional amphibian surveys. Furthermore, focused canopy sampling techniques are time-consuming, require specialized equipment and training, and, in the case of bromeliads, sampling is typically destructive. In this study, we developed and tested a new passive sampling technique for amphibians in bromeliads, which can be easily implemented in common amphibian surveys in the Neotropics. Our study was conducted in five different forests along an elevation gradient (0–2,200 m a.s.l.) in the central region of Veracruz, Mexico. In each forest, 15 tank bromeliads were relocated on large trees at 1.5 m above the ground (n = 75) by fastening them onto metal rings attached to the trees. Over a period of one year, these bromeliads were inspected monthly for amphibians. In total, we recorded 34 individuals belonging to eight species, including small and rare species that are normally difficult to find in the field. This technique appears to be effective in detecting frogs and salamanders across a range of ecosystems, especially in the cloud and mangrove forest where they were found more frequently throughout the year. Bromeliad relocation represents an alternative sampling technique for arboreal amphibians, which reduces the number of bromeliads that have to be sacrificed, requires few resources and minimal prior knowledge, and can be implemented effectively in studies that need repeated sampling through time.

El género Borrelia es un grupo de bacterias helicoidales el cual está divide filogenéticamente en tres clados principales, el que comprende a las borrelias asociadas con reptiles, el que incluye al agente causal de la Fiebre Recurrente y el grupo de Borrelia burgdorferi s.l. Dada la importancia de las borrelias como agentes patógenos, el objetivo del presente trabajo fue recopilar la información existente hasta el 2017 acerca de las borrelias detectadas en los reptiles y sus garrapatas asociadas. Para ello se realizó una búsqueda bibliográfica exhaustiva. Se encontró un total de 26 artículos publicados. Un total de 20 especies de reptiles y anfibios han sido registradas como potenciales hospederos de Borrelia, destaca el orden Squamata con 17 especies, seguido por el orden Testudines con tres especies positivas para alguna especie de Borrelia. Asociados con los reptiles, se encontraron 11 especies de garrapatas duras (7 Amblyomma, 3 Ixodes, 1 de Dermacentor y 1 Hyalomma) positivas c...

Abstract Climate change-driven modifications in thermal and precipitation patterns can result in shifts in species distributions. Avian species in humid mountain forests (HMF) are among the most vulnerable to these atmospheric changes. In this study, we assessed the extent to which climate change could cause distribution shifts in 34 bird species spatially restricted to HMF ecosystems in Mexico. In addition, we analyzed the representation of the species in protected areas (PAs) and the extension these areas covered in the entire range of each species. Species distribution models (SDMs) were generated using Maxent algorithm. Future SDM scenarios were considered using two scenarios: The Interdisciplinary Climate Research Model (MIROC5) and The Community Climate System Model (CCSM4) with a single representative concentration pathway (RCP6.0). We found that by 2050, under MIROC5, modeled species distributions showed an average reduction of 34%, and under CCSM4, a decrease of 40%. By 2070, MIROC5 showed an average a reduction of 51% and under CCSM4 of 54%. SDMs for 20 species overlapped with protected areas (PA), although nine species would reduce their presence in the PAs by 2050 under MIROC5 and 11 under CCSM4. By 2070, 11 and 12 species respectively for both scenarios, would reduce their distribution range in the PAs. More than 94% of the bird species considered, have less than 10% of their distribution in PAs in the current and future scenarios. The species distribution models of 14 species, particularly those of small range, showed no overlap with any PA under the current or future scenarios. To ensure that HMF endemic bird species are represented in different protected areas in the future, conservation schemes such as protected social and community areas and biological corridors could be valuable in ensuring the conservation of endemic birds in the long-term, especially in those regions underrepresented by PAs.

Species Distribution Models (SDM) are currently common currency as proxies of species distribution range, and using consensus among different algorithms is becoming the latest tendency. This information is frequently used to estimate conservation status or for conservation planning. Nonetheless, different algorithms have huge variation in the outcomes. Usually experts determine whether or not a model is accurate, often followed by a trimming process. However, this accuracy estimation cannot be reproduced. Using Mexican endemic amphibians we evaluate the performance of nine modelling algorithms (Artificial Neural Networks, Classification Tree Analysis, Flexible Discriminant Analysis, Generalised Boosting Model, Generalised Linear Models, Multiple Adaptive Regression Splines, MaxEnt, RandomForest, Surface Range Envelope), their strict geographic consensus, locality records and simple convex-hull areas through comparison of: (1) their presence/absence within Mexico's governmental protected areas, (2) range sizes projected, and (3) differences in estimated richness by all methods. We conducted all good practices prior modelling but removed the trimming factor after modelling to make the process repeatable. Presence–absence threshold was determined through the use of the receiver-operating characteristic (ROC). Presence within conservation network of strict consensus and locality records was similar which indicates an over-fitting of the former, the rest of the algorithms performed similarly, with exception of Surface Range Envelope. Richness patterns varied greatly among algorithms. Distribution borders were the areas with higher sensitivity. MaxEnt obtained the highest performance in omission but consensus performed best in correctly predicting species ranges. Closer interaction between curators and modelers would increase SDMs accuracy, which would improve conservation planning effectiveness.

Given the current speed of land use change, we cannot expect to save all species from extinction, and so must decide how to focus limited resources to prevent the greatest number of extinctions. This paper proposes a simple conservation triage method that: evaluates ...

El bosque mesófilo de montaña (BMM) es un ambiente altamente rico en especies de flora y fauna en México. La notable diversidad de especies resalta aún más cuando se analizan también los endemismos en este ambiente. En el presente estudio se describe la importancia de endemismos de vertebrados terrestres en México, considerando los grupos de anfibios, reptiles, aves y mamíferos. Asimismo, se realiza un compendio de las principales causas que afectan tanto a la diversidad bio- lógica como al mantenimiento de las áreas con BMM en México. En el BMM podemos encontrar un alto número de especies y endemismos de anfibios (231 especies y 118 endemismos), reptiles (310 especies, 146 endemismos), aves (547 especies, 72 endemismos) y mamíferos (257 especies, 85 endemismos). Las regiones del Sureste de México, como Chiapas y Oaxaca, contienen tanto la mayor riqueza de especies como de endemismos. Estos endemismos resultan prioritarios a la hora de establecer medidas y estrategias de conservació...

En México, uno de los principales mecanismos para preservar la biodiversidad son las áreas naturales protegidas (ANP). No obstante, para poder implementar acciones eficaces de conservación, es indispensable saber qué especies habitan en las ANP (gubernamentales y privadas), y en qué categoría de riesgo se encuentran. Utilizando las áreas de distribución y categorización de la UICN, la NOM-059 y la serie VI de vegetación y uso de suelo, planteamos una priorización para la conservación de los anfibios de México. Proponemos 5 categorías para que las especies puedan ser reevaluadas constantemente determinando su prioridad: 1) especies que no están en ninguna ANP y que tienen 100% del área modificada; 2) especies que no están en ninguna ANP, y que tienen entre 70 y 99% del área modificada; 3) especies microendémicas que no están en ninguna ANP, sin importar la cantidad de área modificada; 4) especies microendémicas que están en una ANP y que entre tienen entre 70 y 99% de área modificada...

In the present study, we characterized species of bacteria and fungi across a frog community in a seasonal tropical environment in the Natural Protected Area (NPA) Las Musas, Guanajuato, Mexico, using morphological and biochemical protocols. Our three main objectives were to: i) identify the species of microorganisms present in the frog community, ii) determine microorganism prevalence and how it changes throughout the year, and iii) detect diseases and injuries caused by pathogens (bacteria and fungi). Across 150 anurans analyzed, seven species of anurans especies (Anaxyrus compactilis, Incilius occidentalis, Dryophytes arenicolor, D. eximius, Hypopachus variolosus, Lithobates neovolcanicus y Spea multiplicata) hosted at least four genera of pathogenic fungi (Penicillium, Rhizopus, Aspergillus y Batrachochytrium) and two genera of pathogenic bacteria (Aeromonas hydrophila and Pseudomonas sp.). We found the prevalence of positive cases was higher in autumn (0.51) than in summer (0.1...

Hertz et al. (1993) designed what is now the most widely used protocol to analyse the thermal strategies and efficiency of small squamates. Preferred temperature range (Tp) is one of the most important variables required for determining the thermal efficiency index, and is calculated by monitoring the body temperature of the individuals in an enclosure containing a thermal gradient. Although thermoregulation studies of lizards have traditionally employed thermal gradients under laboratory conditions, this approach is not suitable for snakes given that such thermal gradients do not accurately represent their natural thermal environment and thus may result in snakes selecting suboptimal temperatures. Here, we compare the results of this thermal efficiency protocol using a laboratory thermal gradient (LG) and a semi-captivity thermal gradient (SCG) in the rattlesnake Crotalus polystictus. We found traces of seasonal variation in the SCG Tp, but this could not be assessed in the LG. Tp ...

Knowledge about the dynamics of regional diversity patterns is a foundation on which measures aimed to protect diversity dimensions in the light of climate change can be constructed. Here, we describe taxonomic, phylogenetic, and functional diversity patterns of amphibians in the Yucatan Peninsula and their representation in the current protected area system. We stacked current and future potential distribution models to estimate taxonomic diversity and, based on the most recent amphibian phylogeny and nine functional traits, we measured phylogenetic and functional diversity. Independent phylogenetic and functional metrics were obtained by applying null models that allowed us to identify the presumably signature mechanisms underlying assemblage formation. We evaluated the effectiveness of the protected areas in protecting diversity dimensions across scenarios. We found phylogenetic and functional clustering as a result of environmental filters that have allowed only recently diverge...

Las especies que forman parte de una comunidad pueden estar restringidas por los recursos disponibles. Uno de ellos es el espacio acústico, donde en caso de existir solapamiento puede verse afectada la comunicación entre conespecíficos y, potencialmente, la reproducción. Por esta razón, cabe esperar que las comunidades de anuros que presentan una marcada estacionalidad tengan una segregación de nicho en el espacio acústico, debido a su solapamiento en el tiempo. Mediante sistemas de grabación automática (SGA) y grabaciones manuales (370 horas de grabación), registramos la actividad acústica y las vocalizaciones de una comunidad de anuros en Nahá, Chiapas, México durante el periodo octubre 2013 a junio 2014. A partir de 216 cortes de audio pertenecientes a 7 especies, analizamos las grabaciones y registramos 15 características acústicas para cada especie a fin de evaluar el solapamiento espacial, temporal y estructural del nicho acústico, además de estimar la amplitud del nicho media...

Anuran calling activity has been widely associated with abiotic factors, such as temperature, rain and photoperiod. In this sense, mathematical modelling could help us to decipher the mechanisms that underlie these phenomena in order to be able to predict possible scenarios. Here, we propose 15 models that incorporate some environmental variables with biologic relevance: photoperiod, accumulated rain, dry/wet season, and annual mean temperature. The calling activity patterns were obtained with an automated recording system (ARS) for 7 months in Nahá, Chiapas, Mexico, where nine species were recorded. Those models were compared through the Akaike information criterion corrected for small samples (<i>AIC<sub>C</sub></i>) to find the one that best fits. Our results point to a sinusoidal model containing photoperiod, dry-wet season and accumulated rain as the best model. Photoperiod resulted as a critical variable driving phenological calling activity patterns since whenever it was incorporated in a model, its AICC values were reduced. It is interesting because the photoperiod, through photoreception, allows anurans to synchronise their physiology and behaviour throughout the year, being able to control the growth, development and maintenance of organisms by starting the reproduction phases in optimal seasons for their development. However, it is also important to highlight that phenological structure of the anuran calls in Nahá, México is better explained by a combination of mechanisms, which includes photoperiod, rainfall and seasonality, but not temperature.

Amphibians are the most abundant terrestrial vertebrates on Earth. They are crucial in maintaining the transfer of energy and matter from freshwater to terrestrial systems and are also indicators of ecosystem health. Mexico hosts great amphibian diversity with high levels of endemism. Nevertheless, the knowledge of amphibian ecology in the country is at an early stage. This thesis aspires to contribute to the knowledge of Mexican amphibian ecology and to the understanding of the processes underlying amphibian responses to environmental changes.To do so the thesis includes: 1) analyses from fine scales (at landscape level) based on data from two consecutive rainy seasons of fieldwork (nocturnal sampling), in two protected areas in southern Mexico, La Pera and Nahá; 2) at regional scales, analyses based on spatial databases of conservation instruments (i.e. environmental services, governmental, private, and community protected areas, etc.) generated specifically for Mexico; 3) to coarse scales (the whole country), analyses based on ecological niche modelling using the most complete database for Mexican amphibian records and climate layers developed purposely for the country. Thus, the thesis involves different time-scale processes, from ecological to biogeographical. In addition this thesis contains an analysis of the media representation of amphibian biodiversity threats and issues, specifically climate change, based on literature research. I was involved in the process of generating most of the databases used in this thesis.Whilst the main theme of this thesis is amphibian conservation, it also encompasses a wide range of specific subjects. Firstly, foundational knowledge about amphibian conservation is established in Chapter I. Also, the region, Chiapas in southern Mexico, where the fieldwork was carried out for two consecutive years (2009-2010) is described within a historical context and a glossary of terms is presented. In Chapter II, based on one year of fieldwork in two fragmented protected areas (PAs) of different management category, one state and one biosphere reserve, I examine how community structure is related to key features of the environment. The possible effects of governance issues in protected areas and their relationship with the drivers of amphibian metacommunities are also explored. A total of 144 transects were sampled from 33 patches in La Pera and 140 transects from 36 patches in Nahá. In each transect environmental variables were recorded. Partial Canonical Correspondence Analyses (partial CCA) indicated that the drivers of metacommunity patterns vary between the sampled landscapes. Habitat structure explained more of the community variation than either space or weather conditions: > 50% for La Pera and 30% Nahá; but the relationship to geographical space and local climate varied greatly. The differences in relationships among the environmental variables and between them and the amphibian metacommunities finds expression also in the pattern of human exploitation of these areas, which has latterly at least also found expression through differing governance.In Chapter III, the effects of environmental variation on metacommunities structure are explored. Metacommunity theory assumes that emergent properties can be determined that characterise a set of linked communities within a landscape. It follows that change in environmental conditions should generate changes in the metacommunity structure. In La Pera a total of 30 patches were sampled, with a total of 120 transects in 2009, and 133 transects in 2010. In Nahá 31 patches were sampled, with a total of 111 transects in 2009 and 122 transects in 2010. In the analyses of this chapter only transects sampled in both years are included. The total number of individuals increased greatly from 2009 to 2010, but the most abundant species between surveyed years varied slightly, in both areas. In La Pera metacommunity the structure changed from quasi-Clementsian to quasi-Gleasonian, while in Nahá it changed from Clementsian to Gleasonian. CCA show that the variance explained between years was similar. Re-arrangements in the metacommunity structures linked to environmental changes are observed. Results show that amphibian metacommunity structure can change with short environmental changes or disturbances, mainly weather variations from one year to another. This would suggest that metacommunity structures are a dynamic property in fluctuating systems.The aim of Chapter IV is to assess patterns of beta diversity for Mexican terrestrial vertebrates, and explore their relationships with environmental heterogeneity metrics at different spatial scales, identifying the most important surrogates at each spatial scale. The analyses in this chapter are based on the most complete database of Mexican terrestrial vertebrates, comprising distribution maps of 2513 species: 883 resident birds, 344 mammals, 364 amphibians and 811 reptiles. Higher β-diversity…

On 7 December 2016, the federal government of Mexico published an Agreement listing Exotic Invasive Species for Mexico ([ 1 ][1]). However, the report contains inaccurate information about the species and ambiguous measures regarding the prevention, control, and eradication of these species.

3 4 5 6 7 8 9 10 ... 28 29 30 31 32 33 34 35 36 37 38 39 40 41 ... Autores por orden alfabético: Héctor Arita3, Patricia Dávila4, Oscar Flores-Villela5, Gonzalo Halffter6, Andrés Lira-Noriega1, Claudia E. Moreno7, Elizabeth Moreno1, Mariana Munguía8, Miguel Murguía4, Adolfo G. Navarro-Sigüenza5, Oswaldo Téllez4, Leticia Ochoa-Ochoa5, A. Townsend Peterson2, Pilar Rodríguez9 ... 1. DISTRIBUCION ESPACIAL DE LAS ESPECIES DE PECES ... Autores: Salvador Contreras-Balderas10, Roberto Mendoza Alfaro11 y Carlos ...