Bat frugivory in two subtropical rain forests of Northern Argentina: testing hypotheses of fruit selection in the Neotropics

SÁNCHEZ MARIANO S.; GIANNINI NORBERTO P.; BARQUEZ RUBÉN M.

MAMMALIAN BIOLOGY

ELSEVIER GMBH

Año: 2012 vol. 77 p. 22 - 31

1616-5047

Phyllostomid bats are prominent components of mammalian assemblages in the Neotropics. With many species specialized in frugivory, phyllostomids represent major partners of fleshy-fruited plants in the mutualism of seed dispersal. Here we present dietary data from two subtropical rainforests of Argentina, where fruit diversity is low and thus offer unique opportunities to test hypotheses of diet selection originally proposed for species-rich tropical assemblages. Particularly, we tested whether frugivorous phyllostomids exhibit pronounced dietary specialization in core plant taxa where greatly reduced as compared to tropical rainforests. We analyzed dietary overlap and niche breadth of subtropical frugivorous bats on the basis of >1000 dietary records plus >500 samples from a fruit offer previous the region. We show that in the subtropics, frugivores from different genera remain faithful to their respective core plant taxa with few exceptions, rather than shifting toward alternative fruit resources in the study sites. This supports predictions of specialization, which is confirmed to have a deep historical origin. The response of phyllostomid ensembles to restricted fruit diversity is at species composition: absence of species for which preferred fruits do not occur in the sites. Taken together, these data lend strong support to hypotheses that explain coexistence of frugivorous the is study level in available phyllostomids the basis of dietary specialization on core plant taxa with chiropterochorous fruits.