Abstract

DOS SANTOS FILHO, Manoel et al. Feeding ecology of Marmosa demerarae (Thomas, 1905) and Marmosops bishopi (Pine, 1981) (Mammalia, Didelphidae) in forest fragments of the southern Amazon . Mastozool. neotrop. [online]. 2017, vol.24, n.2, pp.409-418. ISSN 0327-9383.

We assessed the relative diet composition and level of trophic niche overlap of two sympatric didelphids, Marmosa demerarae and Marmosops bishopi, through the evaluation of food items consumed in forest fragments of different sizes in the southern Amazon region. The stomach contents of 107 individuals (42 M. demerarae and 65 M. bishopi) were analyzed by volume and frequency. The degree of similarity between the diets of the two species was quantified using Pianka’s index. The relative importance of the different food items consumed was quantified with the Index of Alimentary Importance. Both species revealed flexibility in their feeding preferences but consumed predominantly coleopterans. Vegetable items were only identified in the diet of M. demerarae. Trophic niches of these species overlapped greatly (76%), suggesting strong competition for food items between them in the sampled fragments. Marmosa demerarae presented a broader trophic niche, consuming a greater variety of items than M. bishopi. Temporal changes in diet composition was attributed to fluctuations in the availability of food resources and to influence from the pasture matrices within these environments.

Keywords : Coleopterans; Diet overlap; Forest fragments; Pasture matrix.

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