Interação ecológica entre mamíferos terrestres frugívoros e palmeiras neotropicais
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2019-04-26
Autores
Freitas, Paula Akkawi de
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Universidade Estadual Paulista (Unesp)
Resumo
As palmeiras são consideradas um recurso chave para os mamíferos terrestres tropicais. Entretanto, como as hiper-diversas guildas de frugívoros das florestas tropicais exploram recursos de palmeiras e coexistem, ainda é pouco compreendido. Neste trabalho, avaliamos como três espécies de mamíferos frugívoros terrestres, o queixada (Tayassu pecari), seu parente próximo, o cateto (Pecari tajacu) e a cutia (Dasyprocta azarae) interagem entre si e com os frutos de três espécies de palmeiras em uma floresta tropical da Mata Atlântica do Brasil. Utilizamos armadilhas fotográficas e modelos de ocupação para examinar as interações competitivas entre eles. Ao contrário de nossas expectativas, não encontramos evidências de exclusão competitiva entre esses frugívoros. Os queixadas exploraram principalmente as áreas de grande abundância da palmeira hiper-dominante Euterpe edulis, enquanto as cutias concentraram seu forrageamento em áreas com grande abundância de Syagrus oleracea e, em menor escala, Syagrus romamzoffiana. Os queixadas também responderam positivamente a Syagrus oleracea, mas apenas na ausência de cutias. Os catetos preferiram áreas de alta abundância de Syagrus romamzoffiana onde as outras duas espécies apresentaram baixa detecção ou estavam ausentes. Estes resultados sugerem que, apesar de ocuparem habitats semelhantes, estarem ativos durante as mesmas horas e compartilharem recursos de palmeiras semelhantes, as estratégias comportamentais dessas espécies permitem que elas coexistam.
Palm fruits are considered a key resource for tropical terrestrial forest-dwelling mammals. Yet, how hyper-diverse assemblies of frugivores in tropical forests exploit palm resources and coexist despite high diet overlap remains poorly understood. Here, we evaluate how three species of terrestrial frugivorous mammals, the white-lipped peccary (Tayassu pecari), their close relative the collared peccary (Pecari tajacu) and the agouti (Dasyprocta azarae), interact with each other, and with the fruits of three palm species in a tropical Atlantic Forest of Brazil. We used cameras-traps and occupancy models to examine competitive interactions amongst them. Contrary to our expectations, we found no evidence of competitive exclusion amongst these frugivores. White-lipped peccaries primarily exploited areas of large abundance of the hyper-dominant palm Euterpe edulis, whilst agoutis concentrated their foraging on areas with large abundances of Syagrus oleracea and, to a lesser extent, Syagrus romamzoffiana. White-lipped peccaries also responded positively to Syagrus oleracea, but only when agoutis were absent. Collared peccaries preferred areas of high abundance of Syagrus romamzoffiana where the other two species showed low detection or were absent. These results suggest that despite occupying similar habitats, being active during the same hours and sharing similar palm resources in an isolated forest fragment, behavioural strategies of these species allow them to coexist.
Palm fruits are considered a key resource for tropical terrestrial forest-dwelling mammals. Yet, how hyper-diverse assemblies of frugivores in tropical forests exploit palm resources and coexist despite high diet overlap remains poorly understood. Here, we evaluate how three species of terrestrial frugivorous mammals, the white-lipped peccary (Tayassu pecari), their close relative the collared peccary (Pecari tajacu) and the agouti (Dasyprocta azarae), interact with each other, and with the fruits of three palm species in a tropical Atlantic Forest of Brazil. We used cameras-traps and occupancy models to examine competitive interactions amongst them. Contrary to our expectations, we found no evidence of competitive exclusion amongst these frugivores. White-lipped peccaries primarily exploited areas of large abundance of the hyper-dominant palm Euterpe edulis, whilst agoutis concentrated their foraging on areas with large abundances of Syagrus oleracea and, to a lesser extent, Syagrus romamzoffiana. White-lipped peccaries also responded positively to Syagrus oleracea, but only when agoutis were absent. Collared peccaries preferred areas of high abundance of Syagrus romamzoffiana where the other two species showed low detection or were absent. These results suggest that despite occupying similar habitats, being active during the same hours and sharing similar palm resources in an isolated forest fragment, behavioural strategies of these species allow them to coexist.
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Floresta tropical, Armadilhas fotográficas, Competição, Modelos de ocupação, Frugívoros, Tropical forests, Camera-trap, Competition, Frugivores, Occupancy modelling