Local and Landscape Factors Determining Occurrence of Phyllostomid Bats in Tropical Secondary Forests

Abstract

Neotropical forests are being increasingly replaced by a mosaic of patches of different successional stages, agricultural fields and pasture lands. Consequently, the identification of factors shaping the performance of taxa in anthropogenic landscapes is gaining importance, especially for taxa playing critical roles in ecosystem functioning. As phyllostomid bats provide important ecological services through seed dispersal, pollination and control of animal populations, in this study we assessed the relationships between phyllostomid occurrence and the variation in local and landscape level habitat attributes caused by disturbance. We mist-netted phyllostomids in 12 sites representing 4 successional stages of a tropical dry forest (initial, early, intermediate and late). We also quantitatively characterized the habitat attributes at the local (vegetation structure complexity) and the landscape level (forest cover, area and diversity of patches). Two focal scales were considered for landscape characterization: 500 and 1000 m. During 142 sampling nights, we captured 606 individuals representing 15 species and 4 broad guilds. Variation in phyllostomid assemblages, ensembles and populations was associated with variation in local and landscape habitat attributes, and this association was scale-dependent. Specifically, we found a marked guild-specific response, where the abundance of nectarivores tended to be negatively associated with the mean area of dry forest patches, while the abundance of frugivores was positively associated with the percentage of riparian forest. These results are explained by the prevalence of chiropterophilic species in the dry forest and of chiropterochorous species in the riparian forest. Our results indicate that different vegetation classes, as well as a multi-spatial scale approach must be considered for evaluating bat response to variation in landscape attributes. Moreover, for the long-term conservation of phyllostomids in anthropogenic landscapes, we must realize that the management of the habitat at the landscape level is as important as the conservation of particular forest fragments.

Responses of Tropical Bats to Habitat Fragmentation, Logging, and Deforestation

“…In tropical wet forest in Mexico, abundances of the most common bat species were associated positively or negatively with variation in canopy cover across successional stages, rather than with landscape attributes (Castro-Luna et al 2007a). In contrast, a study in Mexican tropical dry forest found evidence for an important role of local (vegetation complexity) and landscape attributes (area and cover of different vegetation types) as determinants of variation in abundance, which were ensemble specific and scale dependent (Avila-Cabadilla et al 2012). In Central Amazonia, gleaning animalivorous phyllostomid bats exhibited greater abundance and richness in Cecropia-dominated regrowth, whereas stenodermatine frugivores were more abundant in abandoned pastures and Vismia-dominated regrowth, demonstrating that different successional trajectories result from differences in land-use history (cutting versus cutting and burning) that lead to distinct differences in bat assemblage composition (Bobrowiec and Gribel 2010).…”

Community and species-level responses of phyllostomid bats to a disturbance gradient in the tropical Andes

“…Taxonomic identity and time of capture were recorded for each bat. We punchmarked each individual before release with a code in the left wing (Bonaccorso and Smythe, 1972). Punch marks were ephemeral but useful for determining whether a bat had been captured previously.…”

“…Bat responses to habitat conversion can be species-, ensembleand habitat-specific (Avila-Cabadilla et al, 2012;Estrada et al, 1993;Fenton et al, 1992;Gorresen and Willig, 2004;Pinto and Keitt, 2008). However, most previous studies examined responses in terms of species abundance and species richness, whereas only a few have considered bat behavioral responses evaluated in terms of temporal activity patterns (Castro-Arellano et al, 2009;Presley et al, 2009aPresley et al, , 2009b.…”

Effects of Habitat Structure, Plant Cover, and Successional Stage on the Bat Assemblage of a Tropical Dry Forest at Different Spatial Scales

“…For example, the nectarivorous Glossophaga soricina occurs at a greater abundance in sites with a high diversity of forest types when considering a 500 m buffer in radius. On the other hand, Leptonycteris yerbabuenae, which is also a nectarivorous species, was influenced by this variable at a scale of 1000 m in a tropical dry forest in Mexico [13]. In contrast, a study carried out in the Amazon showed that bat responses to the landscape varied among species regardless of the analyzed scale [17].…”

“…There are much fewer studies on this topic for tropical dry forests in comparison with rainforests especially in Brazil. Nevertheless, a study conducted in a dry forest in Mexico found a negative relationship between the abundance of nectarivorous bats and the size of dry forest fragments and found a positive relationship between the abundance of frugivorous bats and the percentage of riparian forests [13]. Understanding the effects of habitat structure on the bat assemblage is extremely important for interpreting the observed patterns and supporting management plans [14,15].…”