Conservation and Future Directions for Bats and Plants

Bats and plants clearly share a long history of mutual interactions and therefore exhibit specialized adaptations in extant species. These adaptations are evidence for coevolution between bats and plants and have been crucial to the establishment of pollination mutualisms. However, deforestation and human activities are threatening the persistence of bat-plant pollination mutualisms in recent times. In a land survey experiment, Garcia-Morales et al. (2013) found that all Neotropical bats responded negatively to human-use landscapes, including urban areas and monoculture crop fields. While Phyllostomid frugivores responded positively to agroforestry areas in this study, mainly due to increased fruit availability, overall bat diversity decreased (Garcia-Morales et al. 2013). The authors also found that human use areas were particularly detrimental to specialized nectarivorous bats. Since nectarivorous bats are among the most important bat pollinators of plants, human-induced land use change could threaten the persistence of specialized bat-plant pollination mutualisms. Deforestation is also displacing bat pollinators to edge habitat areas and thus pushing them farther from their foraging grounds (Kunz and Fenton 2003). By interfering with the feeding patterns of nectarivorous bats, deforestation may thus result in decreased pollination efficiencies of these specialists and threaten their plant hosts by extension. Similatly, Cosson et al. (1999) found that habitat fragmentation in French Guiana decreased the foraging range of nectarivorous bats, greatly reducing the chance that specialized nectarivores would visit their preferred plant host. This could translate into pollination frequency declines and thus threaten bat-plant pollination mutualisms in the area.

In addition to disrupting pollination activity, deforestation also threatens ecosystem services that bats provide including insect control, seed dispersal, and forest regeneration (Kunz and Fenton 2005). Frugivorous bats are important seed dispersers to many tropical plant species by increasing regional population size (Becker et al. 2010). By expanding plant species range, bats could potentially be important agents of promoting forest regeneration in deforested areas; Racey and Swift (1995) report that seed dispersal patterns vary between bats of different size categories, families, and feeding behaviors. Therefore, a heterogeneous pattern of seed dispersal occurs throughout forests with bat seed dispersers (Racey and Swift 1995).

Future studies should focus on the patterns of pollination efficiency of bat pollinators in disturbed habitats. Although the majority of the world’s plants rely on multiple pollinators for fertilization, there are still highly specialized relationships between bats and plants that need to be protected. If deforestation continues at current rates, the pollination mutualisms between bats and plants that have developed from millions of years of coevolution could vanish in the near future. In addition, other important ecosystem services provided by bats and their interactions with plants are at risk. The loss of even a single bat or plant species could have devastating consequences on an entire ecosystem, as specialized adaptations between bats and plants have required ideal circumstances over long periods of time in order to fully develop. These circumstances may never occur again in our Earth’s history, and therefore coevolved specialist species like bats and their hosts are important to conserve. 

Borrow (2008). Little red flying fox (Pteropus scapulatus). 

References

Becker, N.I., Rothenwöhrer, C. & Tschapka, M. 2010, "Dynamic feeding habits: efficiency of frugivory in a nectarivorous bat", Canadian journal of zoology, vol. 88, no. 8, pp. 764-773.

Cosson, J., Pons, J. & Masson, D. 1999, "Effects of Forest Fragmentation on Frugivorous and Nectarivorous Bats in French Guiana", Journal of Tropical Ecology, vol. 15, no. 4, pp. 515-534.

Garcia-Morales, R., Badano E.I. & Moreno, C.E. 2013, "Response of Neotropical Bat Assemblages to Human Land Use", Conservation Biology, vol. 27, no. 5, pp. 1096-1106.

Kunz, T.H. & Fenton, M.B. 2003, Bat ecology, Paperback edn, University of Chicago Press, Chicago.

Racey, P.A., Swift, S.M., Zoological Society of London & Mammal Society 1995, Ecology, evolution and behaviour of bats :the proceedings of a symposium held by the Zoological Society of London and the Mammal Society : London, 26th and 27th November 1993, Published for the Zoological Society of London by Clarendon Press, Oxford.