28 research outputs found

    Habitat Correlates of Jaguar Kill-Sites of Cattle in Northeastern Sonora, Mexico

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    Predation on cattle by the endangered jaguar (Panthera onca) can be a serious ecological and economic conflict. We investigated habitat characteristics of kill sites of cattle in Sonora, Mexico, from 1999 to 2004 to see whether habitat management or cattle distribution could be used as effective nonlethal methods to limit predation. Kill-sites were positively associated with oak, semitropical thornscrub, and xeric thornscrub vegetation types, whereas they were negatively associated with upland mesquite. Sites of cattle kills were also positively associated with proximity to permanent water sources and roads. A model including these relationships fi t kill locations well (AUC = 0.933) and correctly classified 93% of all kill-site locations. Because kill-sites were associated with specific habitat attributes, management practices that alter cattle distribution, such as placement of permanent water sources in uplands, herding, and fencing riparian areas characterized by frequent depredations, can be used to minimize co-occurrence of jaguars and cattle and, thus, potentially limit predation without illegal killing of jaguars. These practices could also lead to more uniform use of pastures and, consequently, higher stocking rates, resulting in increased profitability to landowners. Managing habitat attributes that predispose cattle to predation may provide a viable alternative for maintaining both livestock enterprises and a large endangered carnivore in areas of conflict

    Seroprevalence to and influence of exposure to bovine reproductive disease causative agents on pregnancy and preweaning calf survival of elk (Artiodactyla: Cervidae)

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    Success of recent introductions of elk (Cervus elaphus Linnaeus, 1758) in Mexico partly depends upon elk livestock interactions and conflicts. Disease can impact reproduction of elk and cattle, but is seldom considered in wild ruminants when reproductive output declines. We surveyed serological exposure of elk to causative agents in a bovine abortion profile (i.e., agents of brucellosis, leptospirosis, infectious bovine rhinotracheitis (IBR), bovine viral diarrhea, and neosporosis), as these diseases can negatively affect reproduction of cattle and elk, which frequently co-occur. We determined seroprevalence of exposure to these agents and used hierarchical logistic regression to model both pregnancy and lactation status (a surrogate for calf survival to weaning) as a function of population and exposure to disease causative agents. Tested elk populations were exposed to 2–4 of the agents except for Brucella abortus, which was not present. Pregnancy varied by population (P < 0.016) but not by exposure to any agent (P > 0.213). Proportion of females lactating in autumn did not vary among populations (P > 0.247) nor by exposure to any agent (P > 0.281). Exposure did not affect productivity of elk, despite exposure levels reflective of previous surveys throughout North America and low pregnancy and calf survival in some populations. Because all surveyed elk populations showed exposure to bovine herpesvirus-1 (BHV-1), IBR would be the most likely disease to be introduced with elk, although risk is low given high seroprevalence to BHV-1 among cattle in Mexico. Conversely, brucellosis is endemic in Mexico and can significantly impact productivity of elk. Thus, contracting brucellosis from cattle is the highest disease-related threat to elk introductions or translocation in Mexico.Una parte del éxito de las reintroducciones de ciervo wapití (C. elaphus) en México depende de las interacciones y posibles conflictos con el ganado doméstico. Algunos agentes patógenos pueden impactar la reproducción del wapití y al ganado, pero es raro que se considere para los rumiantes silvestres cuando existe un declive en la productividad de la población. Se investigó la exposición a enfermedades de los wapití utilizando un perfil de aborto bovino (e.g. Brucelosis, leptospirosis, rinotraqueitis infecciosa bovina, (RIB), diarrea viral bovina, e infección por Neospora sp.), ya que estas enfermedades pueden afectar negativamente a la reproducción de los bovinos y rumiantes silvestres, y el wapití y el ganado frecuentemente co-ocurren. Utilizamos una regresión logística jerárquica para modelar la proporción de preñez de las hembras en periodo de lactancia (un sustituto para la supervivencia de la cría al destete) como una función de la población y la exposición de las enfermedades reproductivas. Se hicieron pruebas a poblaciones de wapití y fueron expuestos a 2-4 de los agentes patógenos evaluados, excepto para la brucelosis, que no estaba presente. La preñez de las hembras osciló entre 0.73-0.96 y la proporción de supervivencia al pre-destete desde 0.40-0.67 entre poblaciones. La época de preñez varió por población en todos los contrastes (P <0,016), pero no por la exposición a cualquier enfermedad (P> 0,213). La proporción de hembras lactantes en otoño no varió entre las poblaciones (P> 0,247), ni por la exposición a cualquier patógeno (P> 0,281). La exposición a patógenos no afectó la productividad del wapití, a pesar de los niveles de exposición que reflejan previos estudios en Estados Unidos de Norteamérica y la baja preñez y la sobrevivencia de crías entre algunas poblaciones. Debido a su presencia en todas las poblaciones de wapití en Estados Unidos de Norteamérica, si los productores de ganado adyacentes a los sitios de introducción de wapití en México están viendo menos crías que las esperadas, es posible que quieran vigilar su ganado para IBR para ver si BHV-1 puede ser un posible factor contribuyente, ya que el patógeno está relacionado con la reproducción y es probable que esté presente en los wapití

    Wild turkey (Meleagris gallopavo mexicana) monitoring: Innovation in sampling and estimator of population density

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    Objective: To estimate the population of wild turkey (Meleagris gallopavo, mexicana) and its density in ecosystems of its distribution. Design / methodology / approach: A method based on random sampling with a population density estimator was designed. The design was based on the observation of wild turkeys that go to attraction sites (feedlots) of 2,500 m2 (50 X 50 m) counted in 12 hours a day, three consecutive days. For the total of random sites, the criterion of one site for every 300 ha of surface under study was used. The study was carried out on March 1, 2 and 3, 2019 in 3,000 hectares of pine-oak forest, in Monte Escobedo, Zacatecas, Mexico. Observations were made from a fixed point 25 m from each site, from 6:00 a.m. to 6:00 p.m. The attraction sites were located at a random distance within 10 systematically fixed transects in the study area. Results: The results showed a population of 66 turkeys in 3,000 ha, with a density of 0.022 turkeys ha-1. Limitations / implications: The application of the method was useful for the monitoring of wild turkey in the pine-oak forest, showing that it is a method that does not impact the population, that does not require long sampling times, is reliable, low-cost, and easy to carry out. The method is not reliable in ecosystems that do not allow the location of high visibility sites. Findings / conclusions: Considering the distribution of wild turkey in Mexico, the method is a new alternative applicable to population studies of wild turkey.Objective: To estimate the population of wild turkey (Meleagris gallopavo, mexicana) and its density in ecosystems of its distribution.Design / methodology / approach: A method based on random sampling with a population density estimator was designed. The design was based on the observation of wild turkeys that go to attraction sites (feedlots) of 2,500 m 2 (50 X 50 m) counted in 12 h a day, three consecutive days. For the total of random sites, the criterion of one site for every 300 ha of surface under study was used. The study was carried out on March 1, 2 and 3, 2019 in 3,000 ha of pine-oak forest, in Monte Escobedo, Zacatecas, Mexico. Observations were made from a fixed point 25 m from each site, from 6:00 a.m. to 6:00 p.m. The attraction sites were located at a random distance within 10 systematically fixed transects in the study area.Results: The results showed a population of 66 turkeys in 3,000 ha, with a density of 0.022 turkeys ha -1 . Limitations / implications: The application of the method was useful for the monitoring of wild turkey in the pine-oak forest, showing that it is a method that does not affect the population, which does not require long sampling times, is reliable, low-cost, and easy to carry out. The method is not reliable in ecosystemsthat do not allow the location of high visibility sites.Findings / conclusions: Considering the distribution of wild turkey in Mexico, the method is a new alternative applicable to population studies of wild turkey

    Impacts of chronic wasting disease on a low density mule deer (Odocoileus hemionus) population in the San Andres Mountains, Chihuahuan Desert, New Mexico

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    Chronic wasting disease (CWD), a contagious neurodegenerative disease of cervids, is becoming increasingly prevalent in the arid Southwest including the Chihuahuan Desert ecoregion. Population effects of CWD are uncertain, particularly in arid environments, as previous work has been on relatively high density deer populations in semi-arid or temperate environments. In 2002, CWD was detected in a low density mule deer (Odocoileus hemionus) population in the arid San Andres Mountains, a Chihuahuan Desert range in southern New Mexico. We determined prevalence and distribution of CWD, and mortality and movements of deer, to assess the potential impact on low density deer populations in arid environments. Repeated seasonal primarily ante-mortem sampling found stable prevalence of 0.000–0.091, 2003–2008. Annual CWD mortality rate was <0.02, including deer that were culled. Monitoring of adult radio-collared deer showed no dispersal movements away from home ranges, with maximum movements of ≤20 km; similarly, no juveniles dispersed from maternal ranges. Distribution of infected deer was strongly related to presence of other infected deer. Annual survival rates of mule deer and population rate-of-increase suggested little effect of CWD on population-level mortality given observed prevalence. Transmission and reservoirs of CWD in the SAM were likely limited by low deer densities, patchy distribution, and environmental characteristics (i.e., low clay content of soils) unfavorable to prion persistence, characteristics that are typical of most mule deer populations in the Chihuahuan Desert ecoregion.La enfermedad crónica degenerativa (por sus siglas en inglés: CWD), una enfermedad neurodegenerativa contagiosa de los cérvidos, se está haciendo cada vez más frecuente en el suroeste árido americano incluyendo la ecoregión del desierto de Chihuahua. Los efectos de la CWD sobre poblaciones de cérvidos silvestres son inciertos, particularmente en ambientes áridos, ya que el trabajo previo ha estado en poblaciones de ciervos de densidad relativamente alta en ambientes semi-áridos o templados. En 2002, la CWD fue detectada en una población de venado bura (Odocoileus hemionus) de baja densidad en las áridas montañas de San Andrés, una región del Desierto Chihuahuense en el sur de Nuevo México. Se determinó la prevalencia y distribución de CWD, y la mortalidad y los movimientos de los venados, para evaluar su impacto potencial en poblaciones de baja densidad en ambientes áridos. En el muestreo ante-mortem previo repetido estacionalmente se encontró prevalencia estable de 0,000–0,091, 2003–2008. La tasa anual de mortalidad por CWD fue <0,02, incluyendo venados que fueron sacrificados. El monitoreo de venados con radio-collares adultos no mostró movimientos de dispersión fuera de los rangos de origen, con movimientos máximos de ≤20 km; de manera similar, no hay juveniles dispersos de los rangos maternos. La distribución de los venados infectados estaba fuertemente relacionada con la presencia de otros venados infectados. Las tasas anuales de supervivencia del venado mula y la tasa de aumento de la población sugirieron un efecto pequeño de la CWD en la mortalidad a nivel de la población dada la prevalencia observada. La transmisión y los depósitos de CWD en el SAM (Montañas San Andrés) fueron probablemente limitados por la baja densidad de los venados, su distribución irregular y las características ambientales (es decir, bajo contenido de arcilla de los suelos) desfavorables a la persistencia de priones, características típicas de la mayoría de las poblaciones de venados bura en la ecorregión del Desierto Chihuahuense

    ACTIVITY PATTERNS OF JAGUAR, PUMA AND THEIR POTENTIAL PREY IN SAN LUIS POTOSI, MEXICO

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    Jaguars (Panthera onca) and pumas (Puma concolor) are sympatric species in Mexico and have ecological similarities. The understanding of interespecific interactions between these species are important for effective conservation strategies. We studied activity patterns of jaguars, pumas and their potential prey species through camera-trapping photographs obtained by during four seasonsin the Abra-Tanchipa Biosphere Reserve , San Luis Potosí, Mexico. We described activity patterns of 12 terrestrial vertebrate species, the degree of overlap of jaguar and puma activity; and the prey – predator relationship. Both felids showed cathemeral activity and overlapping between their activities. Jaguar activity showed a significant correlation with eight prey species activity. Puma activity was no related with any prey species activity. Activity peaks of both felids suggest that temporal segregation is a strategy which minimizes interspecific encounters allowing the coexistence of several individuals in this small reserve.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

    Conectividad entre las poblaciones de jaguar en la Sierra Madre Oriental, México

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    "Introduction: The jaguar (Panthera onca) is an apex carnivore that is vulnerable to habitat fragmentation, and some of its populations are believed to be isolated in México where it is classed as endangered. The main the objective of our study was to evaluate connectivity of available jaguar habitat from the Sierra Madre Oriental of México (SMO) towards southern México. Methods: We determined least-cost pathways for jaguar movements among habitat patches in the SMO and identified potential corridors from the SMO. We used recent jaguar presence data and maximum entropy modeling to identify habitat patches in the SMO. We then used the Analytical Hierarchy Process to generate input values for a resistance (landscape permeability) matrix for jaguar movements that we generated using Multi-Criteria-Evaluation with a weighted linear combination. We then modeled least-cost pathways for both dispersal and local movements of jaguars. Results: We identified 581 potential highly suitable habitat patches for the jaguar. Of these, three were > 100 km2 and thus met the criteria for fundamental (i. e. capable of supporting a viable jaguar population) patches. The resistance matrix contained 3 % of low cost and 49 % intermediate cost areas for jaguar movements. Least-cost pathways analysis showed 61 dispersal routes totaling > 2,000 km and > 200 travel routes, with the largest number of both route types in Hidalgo. We also identified potentially five significant corridors for jaguar movement within the SMO and south towards southern México populations. Discussion and implications: We determined that the SMO contains significant jaguar habitat with multiple biological corridors for connectivity with more southern populations of jaguar in México. Based on this, we recommend development of management strategies to facilitate exchange of individuals from the SMO with other known jaguar populations in southern states (i. e. Oaxaca, Tabasco, Guerrero). Principal strategies may focus on habitat management of fundamental patches and habitat restoration between or around stepping-stones. Promoting connectivity among patches and populations which inhabit the SMO will increase its potential as a biodiversity conservation area.

    Adaptability of the threatened jaguarundi (Herpailurus yagouaroundi Schereber, 1777) to human-altered environments in San Luis Potosí, Mexico

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    La persistencia y recuperación de especies raras en regiones en desarrollo con áreas protegidas limitadas depende de su adaptabilidad a los hábitats alterados por el hombre. El jaguarundi (Herpailurus yagouaroundi) está clasificado como amenazado en México, y el conocimiento de su distribución y su correlación con el ambiente es necesario para los esfuerzos de recuperación informados. Sin embargo, poco se sabe sobre el hábitat o la distribución de jaguarundi en el interior de México, incluido el estado de San Luis Potosí (SLP). Realizamos 96 entrevistas semiestructuradas en comunidades, ejidos y ranchos a lo largo de SLP para obtener registros de la presencia de jaguarundi e identificar correlaciones ambientales y atributos de sitios asociados con su ocurrencia. Evaluamos las entrevistas utilizando criterios analíticos de credibilidad y recopilamos información sobre hábitats de 50 eventos confiables de tres de las cuatro regiones geográficas de SLP. En comparación con el paisaje de SLP, las ocurrencias de jaguarundi se ubicaron más cerca del agua, más cerca de las carreteras, a bajas elevaciones, marginalmente más cerca de las comunidades, y en áreas con mayor borde total, densidad de bordes y número de parches de paisaje. El jaguarundi mostró preferencia por los mosaicos de bosques tropicales, agrícolas, de pastizales y urbanos (es decir, cualquier comunidad). Coberturas de escondite relativamente denso o de emboscada generalmente estaban presentes en los sitios de ocurrencia. Colectivamente, el modelo de máxima entropía y el modelo de regresión logística predijeron una probabilidad similar y alta de presencia de jaguarundi en regiones caracterizadas por mosaicos de bosques tropicales, agricultura, pastizales o tipos de cobertura urbana <500 m en elevación y <2 km desde carreteras. Estos paisajes de mosaicos tendían a estar relativamente cerca de comunidades de densidades moderadas de población y agua, y generalmente soportan densidades de presas pequeñas más altas que las áreas menos fragmentadas. Los jaguarundi se adaptaron al menos a las perturbaciones ligeras y moderadas relacionadas con los seres humanos, y pueden verse beneficiados por el aumento de los mosaicos de borde y hábitat.Persistence and recovery of rare species in developing regions with limited protected areas depends upon their adaptability to human-altered habitats. The jaguarundi (Herpailurus yagouaroundi) is classed as threatened in Mexico, and knowledge of its distribution and environmental correlates is necessary for informed recovery efforts. However, little is known of jaguarundi habitat or distribution in interior Mexico, including the state of San Luis Potosí (SLP). We conducted 96 semi-structured interviews around communities, ejidos, and ranches throughout SLP to obtain records of jaguarundi presence and identify environmental correlates and site attributes associated with its occurrence. We evaluated interviews using analytical criteria of credibility, and collected habitat information from 50 reliable occurrences from three of the four geographic regions of SLP. Compared to the SLP landscape, jaguarundi occurrences were located closer to water, closer to roads, at lower elevation, marginally closer to communities, and in areas with greater total edge, edge density, and number of landscape patches. Jaguarundi showed preference for mosaics of tropical forest, agricultural, grassland, and urban (i.e., any community) cover types. Relatively dense hiding or ambush cover was usually present at occurrence sites. Collectively, maximum entropy modeling and logistic regression modeling predicted similar and high likelihood of jaguarundi presence in regions characterized by mosaics of tropical forest, agriculture, grassland, or urban cover types <500 m in elevation and <2 km from roads. These mosaic landscapes tended to be relatively close to communities of moderate population densities and water, and typically support higher small prey densities than less fragmented areas. Jaguarundi were adaptable to at least light–moderate human-related disturbance, and may be benefitted by it because of increased edge and habitat mosaics

    Nuevos registros de tigrillo (leopardus wiedii) en San Luis Potosí, México

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    We documented 36 new records of tigrillo in the region Huasteca of San Luis Potosí, México. This new evidence of tigrillo presence augments its range within the state 38 km west. Records were found mainly in areas with dense vegetation cover including tropical forest and tropical deciduous forest. Results of this investigation suggest tigrillo mainly inhabits areas with dense vegetation cover in this region of Mexico

    Importancia de las áreas naturales protegidas para la conservación de mamíferos terrestres en el sur de la sierra Madre oriental, San Luis Potosí, México

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    Objective: to determine the population status of land mammals in two natural protected areas of the Sierra Madre Oriental Ecological Corridor in San Luis Potosí, Mexico. Design/methodology/approach: the field work was carried out in two sampling periods (from August 2014 to January 2015 and from August 2015 to February 2016) in which two non-invasive techniques were used (photo-traps and tracks identification). The Relative Abundance Index was obtained for each technique. The Mann-Whitney U nonparametric test was performed. Results: the most abundant species via photo-trapping were Sylvilagus floridanus and Sciurus aureogaster, and with tracks were Odocoileus virginianus and Mazama temama in the RBSAT and RFX, respectively. There were significant differences in the abundance of species between sites, being lower in the RBSAT by photo-trapping and higher by tracks. Twenty species were recorded by photo-trapping and 17 by tracks. Limitations on study/implications: the results of this study can be used in natural protected areas and their influence areas, however, the methodology can be applicable elsewhere.   Findings/conclusions: based on the information generated, it is suggested that carnivore abundance decreases southward, and that RFX eventually could not sustain a carnivore population in the long term. Species listed in some risk category were found in both areas, so these areas must be conserved to avoid the disappearance of these wildlife species.Objetivo. determinar el estado poblacional de los mamíferos terrestres en dos áreas naturales protegidas del Corredor Ecológico de la Sierra Madre Oriental en San Luis Potosí, México. Diseño/metodología/aproximación. el estudio de campo se realizó en dos temporadas de muestreo (agosto de 2014 a enero de 2015 y de agosto 2015 a febrero 2016) en las que se utilizaron dos técnicas no invasivas (foto trampas e identificación de rastros). Se obtuvo el Índice de Abundancia Relativa para cada método. Se realizó la prueba no paramétrica U de Mann-Whitney. Resultados. las especies más abundantes vía foto trampeo fueron Sylvilagus floridanus y Sciurus aureogaster y con rastros Odocoileus virginianus y Mazama temama en la RBSAT y la RFX, respectivamente. Hubo diferencias significativas en la abundancia de especies entre sitios, siendo menor en la RBSAT por foto trampeo y mayor por rastros. Se registraron 20 especies por foto trampeo y 17 con rastros. Limitaciones del estudio/implicaciones. los resultados de este estudio pueden usarse en áreas naturales protegidas y sus áreas de influencia, así como, en otros lugares. Hallazgos/conclusiones. con base a la información generada se sugiere que la abundancia de carnívoros decrece hacia el sur, y que la RFX eventualmente pudiese no sostener una población de carnívoros a largo plazo. En ambas áreas se encontraron especies listadas en alguna categoría de riesgo, por lo que estas áreas deben ser conservadas para evitar su desaparició
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