Mamíferos de médio e grande porte em uma área alterada no cerrado : estrutura da comunidade, sobreposição de nicho e densidade

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

Medium and large sized mammals in a disturbed area in the Cerrado: community structure, niche overlap and density. Medium and large sized mammals are affected by fragmentation and habitat changes, and in Cerrado this group corresponds to species preferentially nocturnal, generalist in habitat use and with scarce information about density in modified environments. In an area of 92,000 ha (Fazenda Jatobá) covered by cerrado areas, Pinus spp. and soybean plantations, we investigated community structure (number and species composition and feeding guilds), the pattern of activity and density of species more frequent among nine campaigns between January/2008 and May/2009. Line transects that varied between 5 to 15 km were monitored during daytime and nocturnal periods along 12 days in each campaign, totaling 3,600 km traveled/period. We recorded 29 species at Faz. Jatobá, of which 41.4% belong to the order Carnivora and 37.9% were omnivores. Greater species richness and records were observed at night and in areas of cerrado and Pinus spp. Seven species (Cerdocyon thous, Lycalopex vetulus, Chrysocyon brachyurus, Mazama spp., P. tajacu, O. bezoarticus and Tolypeutes tricinctus) were common in more than 75% of the campaigns, corresponding to about 92% of the records during the study. Except for T. tricinctus, all species are often recorded in several localities of the Cerrado. The composition of species in the biome tends to increase in larger areas and species shared with the adjacent biomes contribute to the structuring of the local community. Canid species, ungulates and three-banded armadillo were representative in trophic structure and occurred all day long. The canids, C. thous, L. vetulus and C. brachyurus, had a high overlap in time, occurring mainly at night. The ungulates Mazama spp., P. tajacu and O. bezoarticus also showed a high overlap in time, being more active during the day. Differences in activity pattern between these two groups reflect a foraging behavior associated with the activity of their prey for canids and a reduction in predation pressure by large carnivores over ungulates. The three-banded armadillo (T. tricinctus) was registered throughout the all day, and probably their pattern of activity involving the consumption of prey such as ants (daytime) and termites (nocturnal period). Through the night sightings were obtained density estimates ranging from 0.053 ind/km2 to O. bezoarticus and 1.200 ind/km2 to T. tricinctus; with the maned wolf (C. brachyurus) exhibiting the highest density for the biome (0.185 ind/km2), reflecting the influence of body size and place of occurrence of species.

ASSUNTO(S)

generalist species density guildas espécies generalistas activity patterns densidade guilds ecologia padrão de atividade

ACESSO AO ARTIGO

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