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1.
Rev. biol. trop ; 66(4): 1559-1568, oct.-dic. 2018. tab, graf
Article in English | LILACS | ID: biblio-1003346

ABSTRACT

Abstract Segregation of daily activity patterns is considered an important mechanism facilitating the coexistance of competing species. Here, we evaluated if temporal separation existed among jaguar (Panthera onca), puma (Puma concolor) and ocelot (Leopardus pardalis) and if their activity patterns were related to that of a particular prey. We used camera trap records to estimate the activity schedules of these predators and their prey. We used the coefficient of overlapping (Δ; ranging from 0 to 1) to quantify the temporal interactions between predators and prey, and calculated confidence intervals from bootstrap samples. Strong temporal overlap occurred among the three felids (Δ = 0.63 - 0.82) in both dry and rainforests. However, a greater temporal separation was observed between the closest competitors (jaguar and puma, puma and ocelot). Jaguar and puma had a strong temporal overlap with medium and large-sized prey, while ocelots' activity matched that of smallsized prey. High overlapping coefficients among the felids suggest that temporal segregation is not the main mechanism facilitating their coexistence in these areas. However, fine-scale or spatiotemporal differences in their activity patterns might contribute to their coexistence in tropical environments.(AU)


Resumen La segregación de los patrones de actividad diaria es considerado un importante mecanismo para la coexistencia de especies competidoras. En este estudio, evaluamos si existía separación temporal entre el jaguar (Panthera onca), puma (Puma concolor) y ocelote (Leopardus pardalis), y si sus patrones de actividad se relacionaban con los de sus presas potenciales. Utilizamos registros de cámaras trampa para estimar los patrones de actividad de los felinos y sus presas. Usamos el coeficiente de traslape (Δ; de 0 a 1) para cuantificar las interacciones temporales entre depredadores y presas y calculamos los intervalos de confianza mediante bootstrapping. Observamos un fuerte traslape temporal (Δ= 0.63-0.82) entre los felinos tanto en el bosque seco como en el lluvioso. La mayor segregación temporal ocurrió entre los competidores más cercanos (jaguar y puma, puma y ocelote). El jaguar y el puma tuvieron un fuerte traslape con las presas medianas y grandes, mientras que el ocelote se traslapó con presas más pequeñas. Los altos coeficientes de traslape entre los felinos sugieren que la segregación temporal no es el mecanismo principal de coexistencia en estos sitios. Sin embargo, pequeñas diferencias en los patrones de actividad (e.g. picos de actividad desfasados) podrían contribuir a su coexistencia en ambientes tropicales.(AU)


Subject(s)
Tropical Climate , Forests , Panthera , Costa Rica
2.
Biota neotrop. (Online, Ed. port.) ; 11(3): 403-406, jul.-set. 2011. ilus, mapas
Article in English | LILACS | ID: lil-610586

ABSTRACT

The exotic alien species Axis axis was introduced in the Americas at the beginning of last century and since then has established itself, expanding its distribution. This is the first record of this species in Brazil. In the extreme south of the country, an individual of A. axis was recorded with a camera trap in the Espinilho State Park. The area is close to the border of Uruguay and Argentina, countries where the species is established and from where this individual presumably originated. The Pampas biome is strongly disturbed by human activity in Brazil and since many native mammal species such as the Pampas deer Ozotoceros bezoarticus are threatened regionally. It is alarming that exotic populations can potentially rapidly expand their ranges in the region, as A. axis deer has done in Uruguay and Argentina. Possible consequences for this invasion are discussed.


A espécie exótica invasora Axis axis foi introduzida no continente americano no início do século passado e desde então se estabeleceu, ampliando sua distribuição. Este é o primeiro registro da espécie para o Brasil. No extremo sul do país, um indivíduo de A. axis foi registrado com armadilha fotográfica, no Parque Estadual do Espinilho. A área é muito próxima a divisa com Uruguai e Argentina, países onde a espécie esta estabelecida e de onde provavelmente o espécime é originário. Visto que o bioma Pampa encontra-se fortemente alterado no Brasil e que muitas espécies da fauna de mamíferos nativa estão ameaçadas de extinção regionalmente, como o veado-campeiro Ozotoceros bezoarticus, é preocupante que populações exóticas estejam ampliando rapidamente sua área de distribuição na região, como fez A. axis no Uruguai e Argentina. Possíveis implicações decorrentes dessa invasão são discutidas.

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