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El gato montés, Lynx rufus, es una de las seis especies de felinos silvestres que habitan en México. Se distribuye desde el nivel del mar hasta los 3,600 m, ocupando una gran variedad de hábitats entre los que se encuentran los desiertos, ecosistemas de montaña y humedales. Sin embargo, a la fecha, no existe información ecológica de la especie en humedales costeros. El objetivo general de este trabajo es proveer la primera información ecológica obtenida de forma sistemática sobre el gato montés en la Planicie Costera de Nayarit (PCN). Evaluamos su presencia histórica y actual, su abundancia relativa y patrones de actividad. Determinamos la presencia histórica del gato montés en la PCN mediante una búsqueda en bases de datos electrónicas utilizando las palabras: “Lynx”, “rufus”, “lince”, “bobcat” y “Nayarit”. Implementamos el protocolo del Censo Nacional del Jaguar usando cámaras trampa en un área de 72 km2 para documentar la presencia, distribución, abundancia relativa y patrones de actividad del gato montés. A través de la búsqueda en bases de datos encontramos 23 registros de gato montés en un área de al menos 3,000 km2 de la PCN. A partir de nuestro trabajo de campo obtuvimos 30 registros independientes con una abundancia relativa de 1.28 fotografías de gato montés / 100 días cámara. Documentamos la presencia de al menos 10 individuos diferentes, incluyendo adultos de ambos sexos y una hembra presuntamente embarazada. Su actividad es nocturna; 40 % de los registros ocurrieron entre las 00:00-06:00 hr. El gato montés habita los ecosistemas costeros de Nayarit. Los valores elevados de abundancia relativa sugieren una población estable en la PCN con respecto a lo que ha sido reportada en hábitat ideales para la especie tales como los matorrales y bosques templados. Su actividad nocturna coincide con lo que reportan otros trabajos para la especie. Aunque, en general, el gato montés se adapta bien al disturbio generado por actividades humanas, los impactos que estas tienen sobre sus poblaciones en los humedales costeros aún se desconocen. Para asegurar la permanencia de sus poblaciones es necesario realizar futuros estudios sobre su dieta, reproducción, ámbito hogareño y conectividad genética de la especie en los ecosistemas costeros del occidente de México.

A new species of hylid frog is described from the southwestern edge of the Mexican Plateau from the states of Morelos and Mexico through Michoacan and Jalisco, reaching the Sierra Madre Occidental in Sinaloa and western Durango. The new species is part of the widespread Mexican hylid Sarcohyla bistincta ( sensu amplo ) complex, comprised of S. bistincta , S. pentheter , S. calthula , and S. ephemera . One subspecies of S. bistincta ( labeculata ) was proposed for an isolated population in Oaxaca. We restrict the group’s nominal species, S. bistincta ( sensu stricto ), to the Sierra Madre Oriental of Mexico and southward into the Sierra Madre del Sur of Guerrero and Oaxaca. Examination of type material places S. calthula and S. ephemera in the synonymy of S. labeculata (new combination). The species allied to S. bistincta, namely , S. bistincta , S. labeculata , S. pentheter , and the new species described herein, are diagnosed and described following recent suggested taxonomic changes and new available material.

ResumenEn febrero de 2019 se fotografió con cámaras trampa un ejemplar de zorra gris (Urocyon cinereoargenteus) 2.4 kilómetros al sur de Los Corchos, Municipio de Santiago Ixcuintla, Nayarit, México. Este representa el primer registro de zorra gris en el municipio de Santiago Ixcuintla y el segundo en la llanura costera del Pacífico de Nayarit, lo que extiende su distribución 88 km al sur del registro de Tecuala y a 48 km al norte de San Blas, Nayarit.Palabras clave: carnivora, fototrampeo, llanura costera del Pacífico, Nayarit, Urocyon cinereoargenteus.AbstractIn February 2019, a specimen of gray fox (Urocyon cinereoargenteus) was photographed with camera traps 2.4 kilometers south of Los Corchos, Municipality of Santiago Ixcuintla, Nayarit, Mexico. This represents the first record of the gray fox for the Municipality of Santiago Ixcuintla and the second for the Pacific coastal plain of Nayarit, extending its distribution 88 km south of record from Tecuala and 48 km north of San Blas, Nayarit.Key words: camera trapping, carnivora, Nayarit, Pacific coastal plain, Urocyon cinereoargenteus.

The American bullfrog (Lithobates catesbeianus), considered as one of the world’s worst invasive species because of its negative effects on native fauna, has been introduced into over 40 countries in four continents. The invasion status in Mexico is poorly known. The first known record for this species in the Peninsula of Baja California, northwestern Mexico is an individual collected 35 years ago. A great portion of the peninsula is an arid desert where the sources of freshwater are the spring-fed oasis and mountain arroyos that support rare and endemic species closely associated with wetland conditions. Humans, who have introduced alien species, inhabit many of those oases. The aim of this work was to document the presence of the exotic bullfrog in 40 oases and mountain arroyos in Baja California Sur state during 2006–2009. Bullfrogs were found in 25% of the oases sampled; 15% have confirmed records of breeding populations and five oases are new location records. Our results show a considerable increase (50%) in the number of oasis invaded by bullfrogs in only 8 years. The animal populations of rare or endemic species associated with oases would be threatened by the arrival of bullfrogs. Actions for their control and eradication are urgently needed.

A widely accepted biodiversity crisis in the tropics has been recently challenged by claims that secondary forests will gradually restore biodiversity losses. This prediction was examined for the herpetofauna in Quintana Roo, Mexico. Quantitative sampling (108 transects) of reptiles was undertaken monthly (January-September 2004) along a vegetation gradient covering induced grasslands, and regrowth and primary rain forests. A total of 35 species was found, 14 being present in and five showing dependence on mature forests. Lizards contributed > 90 per cent of the individuals observed. Reptile abundance and snake species richness was highest in primary forests, even though the lower abundance and richness did not differ between regrowth forest and induced grasslands. Multivariate ordinations and ANOSIM tests displayed clear differences in assemblage structure among vegetation types, mainly caused by contrasting abundances of lizard species having distinctive arboreal or terrestrial habits. There was no evidence that snake assemblages differed between secondary forests and induced grasslands. Microhabitat availability had a key role in shaping species composition through the vegetation gradient. Our results dismiss the hypothesis that secondary forests can act as reservoirs of primary forest reptile diversity on the basis that many taxa depend largely on habitat quality and have specialized life-history traits, and that biological succession does not guarantee the recovery of assemblage complexity.

The frequency of cyclonic storms that generate severe modification of a mountain arroyo ecosystem appears to have served as a selective pressure on native treefrogs resulting in a specific behavior to avoid the negative effects of the floodwaters. Apparently exotic bullfrogs found here lack this evolutionary response because during cyclonic rains they continue their activity and die by being dragged by the heavy water flow. Based on field observations, we propose recommendations for future well-designed studies to explore the role of tropical cyclones as sources of natural selection on native and exotic species exposed to these natural phenomena.