Nicho trofico de Gracilinanus microtarsus (Didelphimorphia: Didelphidae) : variação intra-populacional e inter-individual / Trophic niche of Gracilinanus microtarsus (Didelphimorphia: Didelphidae): intra-population and inter-individual variation

AUTOR(ES)

Leonardo Dominici Cruz

DATA DE PUBLICAÇÃO

2007

RESUMO

The niche theory occupies a central position in the Ecology, having a fundamental role in the population and community dynamic models. Despite this, its traditional formalization is based on the principles of the mean-field and on the law of mass action, which presume that the individuals of a species are ecologically equivalent and their interactions are proportional to their densities. This approach is inadequate in describing the dynamics of trophic niche, since many endogenous and exogenous factors contribute significantly to the variation of the population niche. This study aimed to investigate the diet, the dynamics of the population trophic niche of the gracile mouse opossum Gracilinanus microtarsus (Wagner, 1842) in a cerradão area of São Paulo state, as well as to investigate the influence of the inter-individual variation in this phenomenon. The diet of G. microtarsus was composed of invertebrates and fruits, with the predominance of insects. The trophic niche width of males and females was higher in the warm-wet season than in the cool-dry season. Between sexes, the niche width of males and females did not differ in the warm-wet season and in the cool-dry season. Females presented larger niche width than males. At the individual level, the niches of males and females were similarly proportional to their populations. However, in the cool-dry season, this similarity was higher. Neither amostral size nor number of food resource types detected in faeces influenced these results. This indicates that, in general, the individuals of G. microtarsus behave as opportunistic foragers, using the resources in according to with their availability in the environment .

ASSUNTO(S)

cerrados gracilinanus microtarsus (didelphidae) niche (ecology) ecologia populacional nicho (ecologia) population ecology

Documentos Relacionados

• Area de vida de Gracilinanus microtarsus (Didelphimorphia: Didelphidae) : inferencias baseadas nos metodos do poligono convexo minimo e da modelagem estatistica
• Ecologia populacional e alimentar de Gracilinanus microtarsus (Marsupialia: Didelphidae)
• Geographic variation in Caluromys derbianus and Caluromys lanatus (Didelphimorphia: Didelphidae)
• Extensão da distribuição e ocorrência em simpatria de Gracilinanus agilis e G. microtarsus (Didelphimorphia, Didelphidae) com notas citogenéticas
• Intra- and inter-individual chromosome variation in Hoplerythrinus unitaeniatus (Pisces, Erythrinidae): a population from the Brazilian São Francisco river basin