Frugivorous Bats Maintain Functional
Habitat Connectivity in Agricultural
Landscapes but Rely Strongly on Natural
Simon P. Ripperger1,2*, Elisabeth K. V. Kalko2,3, Bernal Rodríguez-Herrera4,
Frieder Mayer1,5, Marco Tschapka2,3 1 Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany, 2 Institute of Experimental Ecology, University of Ulm, Ulm, Germany, 3 Smithsonian Tropical Research
Institute, Balboa, Panama, 4 Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica, 5 Berlin-Brandenburg Institute of Advanced Biodiversity Research, Berlin, Germany * email@example.com
Anthropogenic changes in land use threaten biodiversity and ecosystem functioning by the conversion of natural habitat into agricultural mosaic landscapes, often with drastic consequences for the associated fauna. The first step in the development of efficient conservation plans is to understand movement of animals through complex habitat mosaics. Therefore, we studied ranging behavior and habitat use in Dermanura watsoni (Phyllostomidae), a frugivorous bat species that is a valuable seed disperser in degraded ecosystems. Radiotracking of sixteen bats showed that the animals strongly rely on natural forest. Day roosts were exclusively located within mature forest fragments. Selection ratios showed that the bats foraged selectively within the available habitat and positively selected natural forest.
However, larger daily ranges were associated with higher use of degraded habitats. Home range geometry and composition of focal foraging areas indicated that wider ranging bats performed directional foraging bouts from natural to degraded forest sites traversing the matrix over distances of up to three hundred meters. This behavior demonstrates the potential of frugivorous bats to functionally connect fragmented areas by providing ecosystem services between natural and degraded sites, and highlights the need for conservation of natural habitat patches within agricultural landscapes that meet the roosting requirements of bats.
Land-use changes are identified as the major threat to biodiversity, with the most devastating impacts observed in tropical biomes . Conversion of natural habitats to arable or commercially usable land leads to habitat fragmentation and the creation of mosaic landscapes.
PLOSONE | DOI:10.1371/journal.pone.0120535 April 1, 2015 1 / 15
Citation: Ripperger SP, Kalko EKV, RodríguezHerrera B, Mayer F, Tschapka M (2015) Frugivorous
Bats Maintain Functional Habitat Connectivity in
Agricultural Landscapes but Rely Strongly on Natural
Forest Fragments. PLoS ONE 10(4): e0120535. doi:10.1371/journal.pone.0120535
Academic Editor: Danilo Russo, Università degli
Studi di Napoli Federico II, ITALY
Received: September 5, 2014
Accepted: January 23, 2015
Published: April 1, 2015
Copyright: © 2015 Ripperger et al. This is an open access article distributed under the terms of the
Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability Statement: A full documentation of primary data that entered statistical analyses is presented in S4 and S5 Tables.
Funding: Funding for field work was provided to SPR by a grant of the “Deutscher Akademischer
Austauschdienst” (DAAD grant number D0948581), https://www.daad.de/de/. Funding to FM by the "German Science Foundation" allowed for the preparation of this manuscript (DFG grant FOR 1508,
Research Unit BATS ”Dynamic Adaptable
Applications for Bats Tracking by Embedded
Communicating Systems”), http://www.dfg.de/. The
Consequences for flora and fauna include community changes in species diversity or abundance [2, 3] and breakdowns of relationships among plants and their dispersers, which are followed by changes in seed bank composition [4–6]. Finally, populations experience loss of genetic diversity and genetic differentiation  that may derive from altered animal movement patterns .
Understanding animal movement is crucial for developing effective landscape level conservation strategies, as movement is a key to successful foraging, mating, or dispersal . However, heterogeneous landscapes are composed of more or less hospitable habitat patches within a non-uniform matrix area. Many studies have shown that the matrix is more accessible to a species the more similar it is structurally to its natural habitat . The response of animals to habitat boundaries may vary among species that evolved either in patchy or in continuous environments and may lead to different levels of susceptibility to habitat fragmentation . Such findings are important to model probability of individuals of a species moving through complex landscapes; yet, such simulations strongly depend upon real data on animal movement and ecology to lay a biological foundation [8, 11].
Telemetry studies contribute to the understanding of human impact on animals and provide essential base information for conservation initiatives . Phyllostomid bats are especially valuable to endangered ecosystems by providing ecosystem services, namely pollination and seed dispersal . Frugivorous phyllostomids and birds play an important role in dispersing seeds to disturbed areas because often other more sensitive fruit-eating taxa have been reduced in abundance by fragmentation itself or by activities such as hunting [14, 15]. Information on habitat use of frugivorous bats is desirable to understand the consequences of human impact, as has been accomplished for other taxa . Most radio-tracking studies on phyllostomid bats in the context of habitat fragmentation either focus on naturally fragmented habitats [16–18] or on anthropogenically modified systems that are composed of forest islands within a strongly contrasting water matrix [19, 20]. The latter work on smaller bats confronted with a water matrix suggests that such species are limited in their foraging range and can only cross narrow habitat disruptions. However, mark-recapture studies in agricultural landscapes provided evidence that several frugivorous and nectarivorous phyllostomid bat species are able to move through mosaic areas while heavily using riparian forests, live fences consisting of planted posts, or corridors [21, 22]. A radio-tracking study in an anthropogenically dominated area showed that two phyllostomid bat species are able to incorporate restored forests into their foraging range . Shade-cocoa plantations may even harbor a more abundant and diverse bat fauna than native forest tracts, if the agroforest sites are neighboring with forest . The evaluation of movement patterns in the landscape context helps to gain a deeper understanding of how bats use distinct elements within highly heterogeneous environments.