Trophic niche of Tropidurus hispidus (Sauria: Tropiduridae) in restinga environment / Nicho trofico de Tropidurus hispidus (Sauria: Tropiduridae) em ambiente de restinga

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The diet is one of the main atributes of the ecological niche of animal species. Generally, the individuals of a population are considered ecologically equivalent in ecological studies that focus on resource use. Nevertheless, this approach has been inadequate to correctly describe resource use by various species, as demonstrated by empirical data. Intrapopulation variation may be caused by exogenous factors or endogenous phenomena such as sexual and/or ontogenetic differences. Additionally, individuals belonging to the same age or sex, and within a single site or time can also show differences in niche. This phenomenon has been defined as "individual specialization" and its occurrence is related to temperate and/or depauperate communities. To verify which phenomena produce niche variation in tropical lizards, we used Tropidurus hispidus as a model system. The aims of this study were to describe the diet composition; to investigate the existence of intrapopulational variation in trophic niche; to determine at which levels this variation is expressed, and test if the morphology is an underlying mechanism in food resource use in this species. The intrapopulation variation seems to be caused uniquely by individual specialization. The most consumed items by T. hispidus, ants, beetles and termites, produce a variety of toxic chemical substances that can impose a high cost for desintoxication and generate individual alimentary preferences. Another possible source of variation is the occurrence of different forage behaviors by individuals of the same population. This is the first record of the occurrence of individual specialization in tropical lizards, which suggests the presence of this phenomenon in highly diverse tropical communities, contradicting the established literature relating the occurrence of individual specialization to temperate and depauperate communities

ASSUNTO(S)

partilha de recursos (ecologia) intrapopulation variation variação intrapopulacional especialização individual (ecologia) individual specialization nicho (ecologia) niche (ecology) resource partitioning (ecology)

ACESSO AO ARTIGO

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