FSD 2010 - Neotropical bats

5th International Symposium-Workshop on Frugivores and Seed Dispersal (1985-2010)

Neotropical bats

Frugivory among bats

In Central French Guiana, one may count 100+ bat species in 9 families, of which obligate and opportunistic frugivorous bat species. In total, 110 spp. from 31 families are dispersed by bats and 181 spp. are potentially dispersed by bats. Among them, 48% are trees (e.g. Chrysobalanaceae) and lianas (e.g. Marcgraviaceae), 27% shrubs (e.g. Piperaceae), 20% epiphytes & vines (e.g. Araceae), the rest (5%) being herbs. Bats equally feed on infructescences (Araceae, Cecropiaceae, Moraceae, and Piperaceae) or entire single fruit (Chrysobalanaceae, Clusiaceae, and Solanaceae). A majority of fruits consumed by bats are away from foliage, or among foliage, or both. Fruits are either berries, drupes, capsules or achenes, green being the dominant fruit color followed by yellow, white, brown, red, black, etc.. Overall, based on a review of plants consumed by frugivores in the Guianas, 45 species overlap in diets of bats, birds, and arboreal mammals.

Seed dispersal by bats

Once consumed, dispersal unit are generally seeds, stone or pyred, or entire fruit (e.g. Cecropia obtusa, Lobova et al. 2003). One may consider different bat-dispersed seed (or fruit) groups depending on whether diaspores are swallowed and digested or carried away into mouth. In the neotropics, one may separate separate bat-dispersed seeds into two groups, i.e. small (< 6 mm) that are ingested with pulp, and rapidly defecated in flight (endozoochory) and large (> 7 mm) ones that are dropped once the pulp has been removed and consumed (exozoochory). Seeds disperse by bats ranges from minute seeds such as Clidemia octona (0.5 x 0.3, Melastomataceae) and Pothomorphe peltata (0.5 x 0.5 mm, Piperaceae) in America up to Balanites wilsoniana (88 x 47 mm, Zygophyllaceae) in Africa. Nonetheless, despite their overall smaller size compared to large paleotropical fruit bat such as fying foxes (Pteropus spp), neotropical frugivore bats such as Artibeus spp. may carry a diversity of seeds and stones larger than 35 mm, what appeared to be an upper limit for many other frugivores animals in both the neo and the paleotropical rainforests (Forget et al. 2007). Seed shape does seem to be a constrain for them as they may carry seeds as round as Andira coriacea (Fabaceae) to elongated one as Dipteryx spp. (Fabaceae). (Photo : Carollia perspicillata by Alex Borisenko © Royal Ontario Museum)

Sources

Lobova, T. A., C. K. Geiselman & S. A. Mori. 2009. Seed dispersal by bats in the Neotropics. New York Botanical Garden Press. (Monograph)

Lobova T.A. et al. 2008. An upcoming monograph on seed dispersal by bats. Poster P1.22. Abstract.

Lobova, T.A. et al. 2006. Plants dispersed by bats in French Guiana: selection, preferences, and dietary overlap. ATBC Meeting, Kunming, China.

Lobova, T. A. & Mori, S. A. 2004. Epizoochorous dispersal by bats in French Guiana. J. Trop. Ecol. 20: 581-582. Abstract

Lobova, T.A. et al. 2003. Cecropia as a food resource for bats in French Guiana and the significance of fruit structure in seed dispersal and longevity. American Journal of Botany 90: 388-403. Abstract