PRIMER REGISTRO DEL TIGRILLO (LEOPARDUS WIEDII, SCHINZ 1821) Y DEL GATO MONTÉS (LYNX RUFUS, KERR 1792) EN LA RESERVA DE LA BIÓSFERA DE TEHUACÁN-CUICATLÁN, OAXACA, MÉXICO

Using camera-traps, two new records of margay (Leopardus wiedii) and two of lynx (Lynx rufus) were obtained at the Biosphere Reserve de Tehuacán-Cuicatlán, Oaxaca, Mexico, in 2003 and 2004. These are the first records documenting the presence of both species in this reserve

Species Distribution Models and Ecological Suitability Analysis for Potential Tick Vectors of Lyme Disease in Mexico

Species distribution models were constructed for ten Ixodes species and Amblyomma cajennense for a region including Mexico and Texas. The model was based on a maximum entropy algorithm that used environmental layers to predict the relative probability of presence for each taxon. For Mexico, species geographic ranges were predicted by restricting the models to cells which have a higher probability than the lowest probability of the cells in which a presence record was located. There was spatial nonconcordance between the distributions of Amblyomma cajennense and the Ixodes group with the former restricted to lowlands and mainly the eastern coast of Mexico and the latter to montane regions with lower temperature. The risk of Lyme disease is, therefore, mainly present in the highlands where some Ixodes species are known vectors; if Amblyomma cajennense turns out to be a competent vector, the area of risk also extends to the lowlands and the east coast

Habitat characterization and modeling of the potential distribution of the Military Macaw (Ara militaris) in Mexico

AbstractForest structure and composition have been used to assess the habitat characteristics that determine bird distributions. The patterns of distribution have been shaped by historical and ecological factors that play different roles at both temporal and spatial scales. The objectives of this research were to characterize the habitat of the endangered Military Macaw (Ara militaris) and evaluate the potential distribution of this species based on trends of land use changes in Mexico. We characterized the community structure and floristic composition of 8 forests that are currently used by the Military Macaw for breeding and feeding and compared the results with 6 similar forests characterized in other studies but without historical records of the presence of the Military Macaw. The Military Macaw preferred sites with high diversity of plant species dominated by trees from 4 to 15m in height and from 5 to 90cm in diameter at breast height. We identified 236 plant species in the 8 forests with 20 species (8.4%) used for nesting and feeding by the Military Macaw. The floristic composition is important for the presence of the Military Macaw because there were significant differences between forests with and without its presence. The potential area of distribution of the Military Macaw had decreased by 32% and the remnant areas are included in only 8 National Protected Areas. The protected areas of natural forests should be increased to preserve the sites of potential distribution and consequently the habitat of the Military Macaw in Mexico

Opuntia in México: Identifying Priority Areas for Conserving Biodiversity in a Multi-Use Landscape

BACKGROUND: México is one of the world's centers of species diversity (richness) for Opuntia cacti. Yet, in spite of their economic and ecological importance, Opuntia species remain poorly studied and protected in México. Many of the species are sparsely but widely distributed across the landscape and are subject to a variety of human uses, so devising implementable conservation plans for them presents formidable difficulties. Multi-criteria analysis can be used to design a spatially coherent conservation area network while permitting sustainable human usage. METHODS AND FINDINGS: Species distribution models were created for 60 Opuntia species using MaxEnt. Targets of representation within conservation area networks were assigned at 100% for the geographically rarest species and 10% for the most common ones. Three different conservation plans were developed to represent the species within these networks using total area, shape, and connectivity as relevant criteria. Multi-criteria analysis and a metaheuristic adaptive tabu search algorithm were used to search for optimal solutions. The plans were built on the existing protected areas of México and prioritized additional areas for management for the persistence of Opuntia species. All plans required around one-third of México's total area to be prioritized for attention for Opuntia conservation, underscoring the implausibility of Opuntia conservation through traditional land reservation. Tabu search turned out to be both computationally tractable and easily implementable for search problems of this kind. CONCLUSIONS: Opuntia conservation in México require the management of large areas of land for multiple uses. The multi-criteria analyses identified priority areas and organized them in large contiguous blocks that can be effectively managed. A high level of connectivity was established among the prioritized areas resulting in the enhancement of possible modes of plant dispersal as well as only a small number of blocks that would be recommended for conservation management

Malaria in Africa: Vector Species' Niche Models and Relative Risk Maps

A central theoretical goal of epidemiology is the construction of spatial models of disease prevalence and risk, including maps for the potential spread of infectious disease. We provide three continent-wide maps representing the relative risk of malaria in Africa based on ecological niche models of vector species and risk analysis at a spatial resolution of 1 arc-minute (9 185 275 cells of approximately 4 sq km). Using a maximum entropy method we construct niche models for 10 malaria vector species based on species occurrence records since 1980, 19 climatic variables, altitude, and land cover data (in 14 classes). For seven vectors (Anopheles coustani, A. funestus, A. melas, A. merus, A. moucheti, A. nili, and A. paludis) these are the first published niche models. We predict that Central Africa has poor habitat for both A. arabiensis and A. gambiae, and that A. quadriannulatus and A. arabiensis have restricted habitats in Southern Africa as claimed by field experts in criticism of previous models. The results of the niche models are incorporated into three relative risk models which assume different ecological interactions between vector species. The “additive” model assumes no interaction; the “minimax” model assumes maximum relative risk due to any vector in a cell; and the “competitive exclusion” model assumes the relative risk that arises from the most suitable vector for a cell. All models include variable anthrophilicity of vectors and spatial variation in human population density. Relative risk maps are produced from these models. All models predict that human population density is the critical factor determining malaria risk. Our method of constructing relative risk maps is equally general. We discuss the limits of the relative risk maps reported here, and the additional data that are required for their improvement. The protocol developed here can be used for any other vector-borne disease

Evaluación de la efectividad de las áreas protegidas para contener procesos de cambio en el uso del suelo y la vegetación. ¿Un índice es suficiente? Evaluation of protected area effectiveness for preventing land use and land cover changes in Mexico. Is an index good enough?

Se examina la efectividad de 44 áreas protegidas federales (AP) en México para evitar procesos de cambio en el uso del suelo y la vegetación (CUSV) y se comparan los métodos y resultados con los de algunos estudios previos. Se cuantificó el porcentaje de superficie transformada (ST) en 2002 y su tasa de cambio entre 1993 y de 2002 y se compararon las tasas de cambio observadas en las AP, en las áreas circundantes de cada AP y en sus respectivas ecorregiones. Se integró un índice de efectividad y se caracterizaron los procesos de CUSV en cada AP. En 2002, el 77% de las AP analizadas tenía menos de 20% de ST; casi 30% mostró una reducción en la ST, en tanto que en otro 30%, el incremento en la ST fue mayor que la tasa promedio de las AP analizadas. Poco más del 70% de las AP mostraron tasas de CUSV menores a las de sus áreas circundantes y en 80% de las AP, las tasas fueron menores que en sus ecorregiones. En general, estos resultados coinciden con estudios previos, pero existen variaciones según el enfoque metodológico utilizado. Consecuentemente, los índices de efectividad deben complementarse con una caracterización detallada de los procesos de CUSV y la interpretación de los resultados debe matizarse en función de los métodos.<br>Effectiveness of 44 federal protected areas (PA) for preventing land use and land cover changes (LULC) in Mexico is examined, comparing results and methodological approaches used in previous studies. We quantified the percentage of transformed area (TS) in 2002 and its rate of change between 1993 and 2002. We compared observed TS rate of change in PA, adjacent areas, and their ecoregions of location. An effectiveness index was build to produce a characterization of LULC processes developed for each PA. In 2002, 77% PA showed less than 20% covered by TS; nearly 30% of PA showed a reduction of TS. Additionally, in 30% of PA, TS increase exceeded the mean rate for all PA. More than 70% of PA showed lower LULC rates than their surrounding areas, and in 80% of PA, these rates were lower than those observed in their corresponding ecoregions. Overall, PA were effective to prevent LULC processes as previously suggested. However, trends derived from this type of analyses depend on methodological specifications. Effectiveness indexes should be complemented with a detailed characterization of LULC processes and their interpretation should correspond to the specific methodological approach used

Identification of areas of endemism from species distribution models: Threshold selection and Nearctic mammals

Evaluamos la relevancia de la selección del umbral en los modelos de distribución de especies en la delimitación de las áreas de endemismo, usando como un caso de estudio a los mamíferos de América del Norte. Modelamos 40 especies de mamíferos endémicos de la región Neártica con Maxent, y transformamos esos modelos a mapas binarios usando cuatro umbrales diferentes: presencia mínima de entrenamiento, percentil diez de la presencia de entrenamiento, igual sensibilidad y especificidad de entrenamiento, y probabilidad logística de 0.5. Los mapas binarios los analizamos con el método de optimación con el objeto de identificar áreas de endemismo y comparar nuestros resultados con estudios previos. La mayoría de las especies mostró tendencias hacia valores muy bajos de la presencia mínima de entrenamiento, mientras que la mayoría tuvo un valor del percentil diez de la presencia de entrenamiento alrededor de 0.5, y de igual sensibilidad y especificidad de entrenamiento alrededor de 0.3. Únicamente con el percentil diez de la presencia de entrenamiento se recuperaron tres de los cuatro patrones de endemismo identificados para América del Norte y se detectaron más especies endémicas. La identificación de áreas de endemismo más eficiente se obtuvo usando el umbral del percentil diez de la presencia de entrenamiento, el cual parece recuperar mejor las áreas de distribución de los mamíferos analizados