Do Current Vampire Bat (Desmodus rotundus) Population Control Practices Pose a Threat to Dekeyser's Nectar Bat's (Lonchophylla dekeyseri) Long-Term Persistence in the Cerrado? Author(s): Ludmilla M. S. Aguiar, Daniel Brito and Ricardo B. Machado Source: Acta Chiropterologica, 12(2):275-282. Published By: Museum and Institute of Zoology, Polish Academy of Sciences DOI: http://dx.doi.org/10.3161/150811010X537855 URL: http://www.bioone.org/doi/full/10.3161/150811010X537855 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Acta Chiropterologica, 12(2): 275–282, 2010 PL ISSN 1508-1109 © Museum and Institute of Zoology PAS doi: 10.3161/150811010X537855 Do current vampire bat (Desmodus rotundus) population control practices pose a threat to Dekeyser’s nectar bat’s (Lonchophylla dekeyseri) long-term persistence in the Cerrado? LUDMILLA M. S. AGUIAR1, DANIEL BRITO2, 3, 4, and RICARDO B. MACHADO1 1Universidade de Brasília, Instituto de Biologia, Departamento de Zoologia, Campus Universitário Darcy Ribeiro, Brasília, Distrito Federal 70910-900, Brazil 2Universidade Federal de Goiás, Instituto de Ciências Biológicas, Departamento de Ecologia, Caixa Postal 131, Goiânia, Goiás 74001-970, Brazil 3Universidade Estadual de Santa Cruz, Programa de Pós-Graduação em Ecologia e Conservação da Biodiversidade, Rodovia Ilhéus-Itabuna km 16, Ilhéus, Bahia 45662-000, Brazil 4Corresponding author: [email protected] The Cerrado is rapidly losing space to agriculture, pastures and urbanization. Current management practices to control rabies outbreaks through the eradication of vampire bat populations may put other bat species in peril. Our objective is to evaluate if the current vampire bat population control practices could pose a threat to Lonchophylla dekeyseri’s persistence, an endemic bat of the Cerrado. We used the VORTEX program to model different vampire bat management scenarios, causing low (25%), medium (50%) or high (75%) incidental mortality to L. dekeyseri populations. Inbreeding depression has been identified as a threat to the species, therefore we also modeled scenarios evaluating such effects. Results show that current vampire bat management practices have serious impacts on populations of L. dekeyseri. In all cases marked declines in population sizes were observed (even when there was no decline in survival probabilities). For medium and high incidental mortality management scenarios, we also observed decreases in survival probability and in genetic diversity. In those scenarios evaluating vampire bat management and inbreeding depression together, the models suggest that such interaction results in more pronounced declines. Habitat loss and fragmentation in the Cerrado are severe threats and have already negatively impacted L. dekeyseri. Unfortunately, if currentpopulation control practices dealing with vampire bats are not changed, inappropriate rabies management may be the coup de grace to the long-term persistence of this species. Key words: Cerrado, Desmodus, Lonchophylla, population viability analysis, rabies, roost INTRODUCTION conservation more urgent (Klink and Machado, 2005). The Cerrado is the most extensive woodland- Bats compose more than 50% of the mammal savanna in South America and one of the world’s fauna in the Cerrado (Aguiar and Zortéa, 2008), and 34 biodiversity hotspots (Myers et al., 2000; they play key roles in ecosystem processes and serv- Mit ter meier et al., 2004). The rapid expansion of ices, as pollinators of native plants (e.g., Martins and agriculture and cattle ranching severely affected Batalha, 2006), as seed dispersers that help to re- the biome and reduced it to 21.6% of its original store degraded areas (e.g., Bizerril and Raw, 1998), area (Mit termeier et al., 2004). A quarter of all and as predators that help to regulate and control grain pro duced in Brazil and nearly 40 million agriculture pests (e.g., Aguiar and Antonini, 2008). heads of cattle represent important economic Bats are also the mammals most commonly in- activities that impact the biome, with steady growth volved in transmission of rabies to humans (Schnei - projected in both industries, as well as in charcoal der et al., 1996; Belotto et al., 2005). In addition to production. Low levels of investment in biodi- rabies-related public health problems, disease trans- versity research, and a small protected areas net- mission by vampire bats to herbivorous species, work (both in number of protected areas and in chiefly cattle, is also a major constraint to livestock total area under protection) only make the Cerrado production in Latin America (Belotto et al., 2005). 276 L. M. S. Aguiar, D. Brito, and R. B. Machado Although the magnitude of the economic impact is en tran ces, destroying native vegetation to open difficult to assess due to the limited information space for pasture, and/or using warfarin to kill bats, available, conservative estimates suggest that the regardless of the species. annual direct and indirect losses to livestock produc- Analyses of the factors that influence population tion due to rabies transmission by vampire bats in viability are important tools for informed decision- a 9-year period are in excess of US$ 50 million, with making and improving the management of wildlife over 30,000 animals being infected with rabies populations (Morris and Doak, 2002). Understand - annually (Steele, 1966; Belotto et al., 2005). With ing factors influencing persistence is particularly cattle ranching industry expansion, ranchers have important for microchiropteran bats, because in ad- complained of livestock losses due to rabies out- dition to their importance in maintaining ecosystems breaks. Not surprisingly, the vampire bat (Desmodus services, 51% of these species are listed as threat- rotundus) is now an important issue and this species ened (Critically Endangered, Endangered or Vul ner - has become the target of population control activi- able), Data Deficient or Near Threatened (Hut son et ties both by local communities and by governmental al., 2001). agencies. Indiscriminate actions against vampire Lonchophylla dekeyseri is an endemic bat of the bats, such as poisoning and roost destruction, are Cerrado (Gardner, 2008) that occurs in 36 localities, routine in central Brazil and may cause incidental structured into six isolated populations (Aguiar et mortality of non-vampire bat species (Mayen, al., 2006a — see also Fig. 1). It requires caves to 2003), putting their long-term persistence in roost and these are found in dry forests associated jeopardy. For example, Aguiar et al. (2006a) ob- with calcareous outcrops (Gardner, 2008; Sampa- served cases of private land owners blocking cave io et al., 2008). Aguiar et al. (2006a) recaptured FIG. 1. Map showing the location of the six known populations of Lonchophylla dekeyseri (grey area shows the limits of the Cerrado biome) Vampire bat management and Lonchophylla dekeyseri viability 277 individuals that used the same roost for at least sev- TABLE 1. Life history parameters of L. dekeyseri used as input to en years, thus highlighting the importance of caves the VORTEX program (data from Aguiar et al., 2006) for this species. Lonchophylla dekeyseri is known to Parameter Value share roosts with D. rotundus (Aguiar et al., 2006b), Breeding system Polygynous and as vampire bat control programs threaten these Age of first reproduction 2 roosts, such associations may bring incidental mor- Maximum breeding age 10 tality to L. dekeyseri. Sex ratio at birth 1:1 Rabies control programs have been identified as % adult males in the breeding pool 25 % adult females breeding 75 a threat to the long-term persistence of L. dekeyse- Litter size 1 ri, particularly through the destruction of roosts Mortality rate (males/females) (Sampaio et al., 2008). There is an urgent need Age class 0–1 22.5 / 15.0 to better evaluate how incidental mortality due Age class 1–2 18.7 / 12.5 to vampire bat and rabies management may affect Age class adult 15.0 / 10.0 the viability of this endemic bat (Sampaio et al., 2008). In this context, our objective is to evaluate if the current practices to manage vampire bat popu- Modeling Scenarios lations and control rabies within the Cerrado, a re- Our baseline scenario comprises the six known populations gion where cattle ranching is economically im- of L. dekeyseri. Each of these populations has 120 individuals portant, could pose a threat to the persistence of that exhibit some degree of site fidelity to their roosts (Aguiar et L. dekeyseri. al., 2006a). For the baseline scenario, we used the demographic data for the species (Table 1), but did not consider inbreed ing depression