Abstract

SANCHEZ DOMINA, Rosarito; DACAR, María A; FERNANDEZ CAMPON, Florencia  and  ALBANESE, M. Soledad. Prey selection of Thylamys bruchi (Marsupialia, Didelphidae) in Central Monte Desert, Argentina. Mastozool. neotrop. [online]. 2020, vol.27, n.1, pp.144-154.  Epub July 06, 2020. ISSN 0327-9383.

Thylamys bruchi is a small and endemic marsupial from Argentina which inhabits the Monte Desert. It presents nocturnal and scansorial habits (i.e. uses terrestrial and arboreal strata) and its diet is omnivorous with a tendency to insectivory, regardless of the fluctuations in food’s availability. The aim of this study was to evaluate the feeding strategy of T. bruchi seasonally, analyzing the selection of prey and the trophic niche breadth. Fieldwork was carried out at the Ñacuñan Man and Biosphere Reserve, Mendoza, during the wet and dry season of 2014 and 2016. This study focused on assessing the composition of arthropods in the diet. For this purpose, we measured prey consumption and their availability in the environment in the different seasons. T. bruchi’s diet presented little seasonal variability, with 70% arthropods and 30% plant material. Eight orders and one family of arthropods were identified, with Lepidoptera being the most consumed ítem. T. bruchi selected Lepidoptera (adults and larvae) and Orthoptera in all seasons. Trophic niche breadth was greater in seasons with less prey availability and narrower when their abundance was greater. Although T. bruchi presents a generalist feeding strategy, in face of seasonal changes in prey abundance, it incorporates most of the available items and partially modifies the composition of its diet by exploiting more abundant items. This flexibility and the consumption of high energy food items such as arthropods may allow T. bruchi to survive in unfavorable and changing environments like deserts.

Keywords : desert; prey selection; trophic niche; Thylamys bruchi.

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