A comprehensive review of dietary strategies of sigmodontine rodents of central-eastern Argentina: linking diet, body mass, and stomach morphology

Abstract

Information on dietary ecology plays a key role in a wide array of biological research and conservation decisions, but its availability is biased towards large and charismatic taxa, whereas small mammals are underrepresented. Of the scarce publications on the Neotropical sigmodontine rodents, most are concentrated in central-eastern Argentina and, up until now, no revision of the totality of these data has been made available. In this work, we performed a thorough review of the dietary information from over 50 publications on 22 species, finding omissions and errors propagated up to the present time. This resulted in a robust database, the proposal of a posteriori dietary categories, and a list of the species that have been neglected in feeding ecology research. In turn, we used that database to test whether the patterns which associate diet and morphology in medium-sized and large mammals could be replicated in these small rodents, despite their overall generalist habits and the restrictions characteristic to their size. We found that larger species tend towards a low-protein diet. Additionally, we identified some stomach types that are restricted to specific diets. These results are consistent with the observations for larger species and shed light on the biology of small mammals.