Assessing the Effects of Landscape-Scale Deforestation on Phyllostomid Bat Assemblages in Brazilian Atlantic Forest Landscapes

Albérico Queiroz Salgueiro de Souza

Habitat loss and fragmentation are major threats to tropical biodiversity. The Brazilian Atlantic Forest has been severely reduced due to deforestation, resulting drastic changes in landscape configuration. The southern Bahia region comprises an important endemism center for faunal species, yet remaining populations are mostly stranded in intensively deforested landscapes. We propose to evaluate the effects of forest loss on phyllostomid bats and ecological processes carried out by them. We will perform bat surveys, identify the consumed food resources and assess network of bat-fruit interactions at 20 forest sites located in a gradient of forest cover at landscape-scale in southern Bahia.

The southern Bahia is one of the major centers of regional endemism in the Brazilian Atlantic Forest and still harbors human-modified landscapes consisted of native forest remnants mainly surrounded by shade cacao plantations, eucalyptus or pastures. Previous studies conducted have shown that the reduction of forest cover at the landscape-scale in this region has pervasively affected both several groups’ vertebrates and plants and fundamental ecological processes for forest maintenance. In this context, we propose to examine how phyllostomids bats are responding to reduced forest cover, evaluate the network of bat-fruit interactions, and whether these changes are affecting key environmental services, such seed dispersal provide by bats.

This study will be carried out on 20 forest fragments located in a gradient (6 - 85%) of native forest cover. Ten mist-nets will be placed in the understory forest, kept open for 6h after sunset (05:00 to 11:00 pm) in two field expeditions, each consisting of three non-consecutive nights of bats surveys. Each captured specimen will be placed individually in numbered cloth bags to enable later for individual identification of the captured species and collection of fecal samples. All captured phyllostomid bats will be identified and individually marked to identify possible recaptures. We will collect the fecal samples from the captured specimens for identify of food resources consumed by frugivorous bats. The feces will be collected and individually stored and will be taken to the Universidade Estadual de Santa Cruz (UESC). The food resources will be analyzed through binocular loupes, aiming to separate seeds existing. The obtained seeds will be identified by comparison to seeds from the UESC herbarium, seeds bank of the Applied Ecology and Conservation Lab and seeds taken from parent plants located in the study area. Five parallel transects the mist nets at each sampling site will be installed to assess the availability of fruits of the plants that are possibly visited by bats. The plants that present fruits will also be collected and taken to the UESC herbarium for later identification with the help of a specialist.

Through this study, we will have information on how diversity patterns of phyllostomid bats are being affected by the loss of forest cover on a landscape scale, what resources are available for the frugivorous bats, and through the construction of networks of fruit-bat interaction we will know which plant species are possible affected by the loss of phyllostomids frugivorous bats species.

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