No abstract

There is little information on the population status of the ocelot Leopardus pardalis in Mexico. In the Sierra Abra-Tanchipa Biosphere Reserve, in San Luis Potosí, ocelots are affected by habitat loss and fragmentation as a result of increased agricultural development. We used photographic identification in camera-trapping capture–recapture surveys to determine population abundance and density during the dry season and subsequent early and late humid seasons during April 2011–March 2012. We recorded 80 photographs of 15 individuals (10 males, one female, and four of undetermined sex) in 7,786 camera-days. Abundance was estimated using a closed capture heterogeneity model, yielding an estimated population of 9 ± SE 3 in the dry season and 21 ± SE 8 and 15 ± SE 5 during the subsequent early and late humid seasons, respectively. Spatially explicit density estimates were 0.04 and 0.03–0.18 individuals per km2 for the dry and humid seasons, respectively, and were similar (P > 0.612) among seasons. Peaks in ocelot activity occurred during 20.00–04.00. We conclude that the ocelots of the Sierra Abra-Tanchipa Reserve have a low population density and may face geographical and biological isolation as a result of habitat conversion. Continued monitoring and improved understanding of the movements and habitat preferences of ocelots are necessary to ensure their continued persistence, and connectivity between this population and others in north-east Mexico.

El jaguar (Panthera onca) y el puma (Puma concolor) en México son especies simpátricas y presentan similitud ecológica. El entendimiento de las interacciones interespecíficas entre estas especies es importante para la elaboración de estrategias efectivas de conservación. Se estudiaron los patrones de actividad del jaguar, el puma y sus presas potenciales, a través del análisis de las fotografías obtenidas en cuatro temporadas de foto-trampeo en la Reserva de la Biosfera Sierra del Abra-Tanchipa (RBSAT), San Luis Potosí, México. Se describieron los patrones de actividad de 12 especies de fauna, el grado de sobreposición en la actividad del jaguar y el puma; y su relación con la actividad de sus presas. Ambos felinos presentaron actividad catemeral con traslape en sus patrones de actividad. La actividad del jaguar está relacionada significativamente con la actividad de ocho especies de presas; la actividad del puma no se relacionó con la actividad de ninguna presa. Los picos de actividad de ambos felinos sugieren que la separación temporal es una estrategia para minimizar los de encuentros interespecíficos que permite la coexistencia de varios individuos en reservas pequeñas.

RESUMENEn las zonas áridas de México habita la candelilla (Euphorbia antisyphilitica), especie con importancia social y económica, pero cuya disponibilidad no está bien definida. El objetivo de este trabajo fue estimar su distribución potencial y abundancia en el norte del estado de Zacatecas. Para la distribución potencial se realizó un modelado mediante el algoritmo MaxEnt ® , donde se usaron 18 registros de presencia: 8 históricos y 10 propios, así como 27 variables predictivas. Se cotejó en campo la presencia mediante 29 puntos aleatorios en el área con distribución potencial y otros 19 fuera de ella. La densidad poblacional se estimó mediante parcelas, se midió la talla de los ejemplares y se consideraron las variables: tipo de vegetación y de suelo, altitud y pendiente del terreno y se realizó la prueba de Kruskal-Wallis. El modelo presentó buena predicción (AUC = 0.920), donde 11 variables contribuyeron con 82.1% en la distribución potencial y las más importantes fueron: tipo de vegetación, exposición, pendiente, altitud y cobertura vegetal. La distribución potencial se encontró en 19.2% del total del área de estudio; la densidad poblacional fue de 295 767.3 individuos por kilómetro cuadrado, influida significativamente por el tipo de vegetación y altitud. La talla de las plantas fue significativamente menor en pendiente escarpada. En 37.9% de los puntos de validación con distribución potencial hubo resultados positivos de presencia de la especie, sin embargo, en 10.5% fuera del área de distribución potencial también apareció. Se concluye que mediante la utilización del algoritmo MaxEnt ® se puede modelar la distribución potencial de plantas silvestres, como la candelilla; la distribución potencial fue discontinua y menor a 20%. ABSTRACTThe candelilla (Euphorbia antisyphilitica) grows in arid regions of Mexico, having social and economic importance, although its availability is not clearly defined.

Introduction:The ocelot (Leopardus pardalis) is a Neotropical cat which is threatened by illegal hunt and habitat destruction in the Mexican territory. Mexican and American authorities are interested in promoting their conservation. The MaxEnt algorithm allows modeling the potential distribution of elusive species, for instance, the ocelot. This has been based on trustable presence records and some other information about the habitat condition. This work was developed with the aim of generating important information about the species in Northeastern Mexico, especially, with the purpose of determining its potential distribution. Methods:Our study was conducted in six physiographic subprovinces in the Mexican states of Tamaulipas and San Luis Potosí. Sixty-trhee recent records about the ocelot were obtained, 41 through literature and 22 from field surveys , between May 2006 to May 2009. In order to develop a prediction model which let us know the animal potential distribution, twenty-seven bioclimatic, topographic, vegetation and anthropic variables were used through the MaxEnt software. Results:The model AUC was of 0.8221 ± 0.009. The most related variables about the ocelot presence were: precipitation of wettest month and quarter, vegetation cover, vegetation type, terrain elevation, precipitation of coldest quarter, terrain slope, human population density, and distance to roads. The potential distribution area overs 20.8 % of the study area. The physiographic subprovinces showing the highest potential distribution were: llanuras y lomerios (7.4 %), Carso Huasteco (4.8 %), Gran Sierra Plegada (4.5 %), and sierras and llanuras occidentales (3.4 %). The llanura costera Tamaulipeca subprovince showed lower potential distribution; meanwhile, llanuras de Coahuila y Nuevo Leon and sierras y llanuras del norte de Guanajuato were not suitable distribution for ocelot. Discussions and conclusions:In order to obtain the ocelot potential distribution model we use recent information collected through field work and surveys. Through this, we could achieve a robust model, where were relevant both bioclimatic and landscape variables. There are patches of habitat important in size and quality for ocelot. The physiographic subprovinces with the roughest landscape were the ones where the highest presence of the species. This study complements the ocelot distributional range in Northeastern Mexico and providing important information about the habitat quality in that portion of the country, as well as the difficulty to possible connectivity between Mexico and USA.Keywords: camera trap; field survey; huasteca region; MaxEnt; neotropical cats. Introducción:El ocelote (Leopardus pardalis) es un felino neotropical que se encuentra amenazado en México por la cacería ilegal y la destrucción de su hábitat. Existe interés de las autoridades de Estados Unidos y de México para conservarlo. El algoritmo MaxEnt permite modelar la distribución potencial de especies elusivas, como el ocelote, con base en registros confiables de presencia, e infor...

Introduction: From different ecological approaches, the coati (Nasua narica) is an important procyonid. Its distribution extends from southern of the United States to Colombia. IUCN (2013) considered it as Least Concern, but in Mexico is not considered under any category of protection due to its wide distribution. Despite this, there is poor knowledge about their population status and current distribution, especially in the northeastern region of the country, where in the last 30 years there have been important changes in land use. The landscape variability that establishes the limit of physiographic subprovinces (PSP) has implications for the availability and quality of habitat for many species, and so this criterion was used. The objective of this study was to estimate the coati potential distribution in four physiographic subprovinces in Northeastern Mexico. Methodology: This study was conducted in northeastern Mexico, on the PSP: Gran Sierra Plegada (GSP), Carso Huasteco (CH); Llanuras y Lomeríos (LL) and Llanura Costera Tamaulipeca (LCT). From estimates the potential distribution was used historical and recent records and 26 predictive variables. The records were obtained from online base dates and articles, and field wok from 2006-2012. This information was analyzed with Maxent algorithm version 3.3.3k (Phillips 2013), obtaining binary maps (presence-absence) using ArcMap 9.3 (ESRI 2006). The potential distribution, as a percentage of the total area, was calculated. Results: We used 110 historical and recent records. Of these, 39 were obtained from databases and 71 fieldwork. The receiver operating characteristic (ROC) analysis showed a value of area under the curve (AUC) of 0.966 ± 0.005. Precipitation, vegetation type, vegetation cover, altitude, slope and temperature were the most relevant variables in explaining the potential distribution model we obtained, with contribution of 70% (Table 2). The potential distribution of coati covers 19.56% of the study area. The greatest distribution areas were found in the PSP's: GSP and CH, followed by LL and LCT. Discussion and conclusions: Coati records for northeastern Mexico were found within a wide range of environmental conditions. Historical records obtained from databases are useful for the modeling of potential distribution, but it is essential to include current records (Pliscoff and Fuentes-Castillo 2011). According to ROC analysis, the model provided a good prediction. The environmental variables that explained the potential of coati distribution are similar to those mentioned in various studies as it is a species adapted to a wide range of altitude, temperature and precipitation. The PSP, GSP and CH met continuity of potential distribution. Despite this, the feasible area for the potential distribution of this species is greatly reduced, and the landscape in general was very fragmented. This fragmentation is a risk for long term viability of coati populations in Northeastern Mexico. It is proposed to establish management plans that combine agricultural ...

Objective: To determine the diet of the desert bighorn sheep and to identify differencesin its composition between sexes during the reproductive and sexual segregation periods.Design/methodology/approach: The study was carried in the UMA Rancho NocheBuena, Hermosillo, Sonora. The microhistological technique and a cell catalog of plantsfrom the study area were used to identify plant species present in fecal samples ofbighorn sheep. The relative frequency, the Shannon-Weaver diversity index and theKulczynski similarity index were determined by sex and period (reproductive andsegregation)Results: The diet of bighorn sheep included 40 species, being herbaceous (36.1 ±4.4%) and grasses (26.8 ±8.9 %) the most common. The diet of males during thesegregation period was mainly composed of grasses (36.2%) and female diet byherbaceous (30%) and grasses (29.8%). No differences were found in the diversity ofthe diet of males and females in the segregation period (H '= 1.0) and in general, their diets were very similar (80%).Limitations/implications: To collect a greater number of fecal samples by sex andperiod (reproductive and segregation) and to analyze the nutritional content of plantsconsumed by bighorn sheep.Findings/conclusions: In this study, the sexual segregation exhibited by the bighornsheep in the Wildlife Management and Conservation Unit Rancho Noche Buena was notdue to food preferences.

The margay (Leopardus wiedii, Schinz 1821) is a small Neotropical cat that is native with distribution from South America into Northeastern Mexico. This species is now threatened by illegal hunting and habitat destruction and, in Northeastern Mexico, their habitat has been fragmented and population sizes have been dramatically reduced. We use the MaxEnt algorithm to model the potential distribution of this elusive species, based on trustable presence records and information about their habitat condition. The aim of this study was to estimate the potential distribution of margays in Northeastern Mexico. We determined potential distribution in the physiographic subprovinces (PSP) of Llanuras y Lomerios, Gran Sierra Plegada and Carso Huasteco. A model was generated using recent and historical records through the MaxEnt algorithm. We used four records from online databases, 36 from literature and 13 from our own fieldwork, as well as 27 predictive variables: 19 associated with climate, two with land use and vegetation type, four associated with topography and two with anthropogenic effects. Seven variables contributed to over 90 % of the distribution model and were highly predictive (AUC = 0.964). The potential distribution of margay represents 9.0 % (7,607 km 2 ) of the area, which is highly fragmented. The PSP Gran Sierra Plegada and Carso Huasteco showed the widest distribution range. The four most relevant variables were: precipitation of the most humid quarter, vegetation type, and both altitude and topographic indexes. We applied species distribution modeling by incorporating recent information collected through fieldwork and surveys as well as historical records in order to predict the margay's potential distribution in Northeastern Mexico. We obtained a robust model based on the most relevant bioclimatic and landscape variables. The landscape in this region is highly fragmented and the largest continuous areas were located in the roughest and inaccessible landscape of the mountainous localities of Gran Sierra Plegada and Carso Huasteco, where an important portion of these PSP maintains continuity in the area of the potential distribution of the margay. Very little is known of the status and abundance of the margay and this study complements our current knowledge of this species in Northeastern Mexico and provides important information regarding the quality of the habitat in this portion of the country. There are several current threats that are being caused by changes in land use in Northeastern Mexico and other parts of their distribution, and this information is essential to establish conservation plans for this species and their habitat. More studies assessing potential distribution throughout their range are needed to support adequate conservation efforts.El tigrillo o margay (Leopardus wiedii, Schinz 1821) es un pequeño felino Neotropical nativo con distribución desde Suramérica hasta el noreste de México. Esta especie se encuentra amenazada por cacería ilegal y por la destrucción de su hábitat. En el n...