We examined seed dispersal by bats and birds in four habitats of the Selva Lacandona tropical rain forest region, Cliiapas, Mexico. The four habitats represented a disturbance gradient: active cornfield, ten-year-old abandoned cornfield, cacao plantation, and forest. Using seed traps examined before sunrise (0400 h) and before sunset (1800 h), we compared volant vertebrate seed dispersal, assuming that seeds found at the end of the night were dispersed by bats and those found at the end of the day were dispersed by birds. We did not find seeds from other frugivores such as monkeys or opossums. In all habitats bats dispersed more seeds than birds. In most months bats also dispersed more seeds than birds, except in December when no seeds were found in the traps. Bats also consistently dispersed more species of seeds than birds, although a x2 comparison showed differences not to be significant. Fifty percent of the spccies represented in the dispersed seeds in all habitats were pioneer species. Cecropia seeds represented a high percentage (up to 87% of those dispersed by bats and up to 83% by birds) of dispersed seeds that fcll in our traps. 'I'hc influence of bars and birds on sccondary successional processes is likely to be fundamental for the establishment of vcgetation. Since bats dispersed more seeds than birds (primarily to disturbed areas and consisting primarily of pioneer species), they are likely to play an important role in successional and restoration processes among habitats as structurally and vegetationally different as cornfields, old fields, cacao plantations, and forest.

The members of the Phyllostomidae, the New-World leaf-nosed family of bats, show a remarkable evolutionary diversification of dietary strategies including insectivory, as the ancestral trait, followed by appearance of carnivory and plant-based diets such as nectarivory and frugivory. Here we explore the microbiome composition of different feeding specialists: insectivore Macrotus waterhousii, sanguivore Desmodus rotundus, nectarivores Leptonycteris yerbabuenae and Glossophaga soricina, and frugivores Carollia perspicillata and Artibeus jamaicensis. The V4 region of the 16S rRNA gene from three intestinal regions of three individuals per species was amplified and community composition and structure was analyzed with α and β diversity metrics. Bats with plant-based diets had low diversity microbiomes, whereas the sanguivore D. rotundus and insectivore M. waterhousii had the most diverse microbiomes. There were no significant differences in microbiome composition between different intestine regions within each individual. Plant-based feeders showed less specificity in their microbiome compositions, whereas animal-based specialists, although more diverse overall, showed a more clustered arrangement of their intestinal bacterial components. The main characteristics defining microbiome composition in phyllostomids were species and feeding strategy. This study shows how differences in feeding strategies contributed to the development of different intestinal microbiomes in Phyllostomidae.

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