Species Richness Patterns and Functional Traits of the Bat Fauna of Arid Southern Africa
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See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/324819399 Species richness patterns and functional traits of the bat fauna of arid Southern Africa Article in Hystrix · April 2018 DOI: 10.4404/hystrix-00016-2017 CITATIONS READS 0 175 4 authors: Ara Monadjem Irene Conenna University of Swaziland University of Helsinki 225 PUBLICATIONS 2,109 CITATIONS 4 PUBLICATIONS 17 CITATIONS SEE PROFILE SEE PROFILE Peter J Taylor Corrie Schoeman University of Venda University of KwaZulu-Natal 211 PUBLICATIONS 2,467 CITATIONS 112 PUBLICATIONS 1,339 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Pan-African Vulture Strategy View project Ecology and behaviour of African small carnivores View project All content following this page was uploaded by Corrie Schoeman on 15 October 2018. The user has requested enhancement of the downloaded file. Published by Associazione Teriologica Italiana Online first – 2018 Hystrix, the Italian Journal of Mammalogy Special Section: Bat Diversity and Ecology in Open Areas Edited by Maria João Ramos Pereira, Damiano G. Preatoni, Lucas A. Wauters and Danilo Russo Available online at: http://www.italian-journal-of-mammalogy.it doi:10.4404/hystrix–00016-2017 Research Article Species richness patterns and functional traits of the bat fauna of arid southern Africa Ara Monadjem1,2,∗, Irene Conenna3, Peter J. Taylor4,5,6, M. Corrie Schoeman6 1Department of Biological Sciences, University of Swaziland, Private Bag 4, Kwaluseni, Swaziland 2Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Private Bag 20, Hatfield 0028, Pretoria, South Africa 3Global Change and Conservation, Helsinki Institute of Sustainability Science, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 65 (Viikinkaari 1), 00014 Helsinki, Finland 4Core Team Member, Centre for Invasion Biology, University of Stellenbosch, South Africa 5South African Research Chair on Biodiversity Value & Change, University of Venda, P. Bag X5050, Thohoyandou, 0950 South Africa 6School of Life Sciences, University of KwaZulu-Natal Private Bag X54001, Durban 4000, South Africa Keywords: Abstract Southern African arid region Kalahari The bat fauna of arid regions is still poorly studied mostly due to a lack of interest in areas with low Namib species richness and a low number of threatened species. In this study, we reviewed the status Succulent Karoo of bat diversity in the arid parts of southern Africa, with the aim of setting up a baseline for Nama Karoo future work. In particular, we described species richness patterns across four arid zones within the species richness region (Namib Desert, Kalahari, Nama Karoo and Succulent Karoo), exploring abiotic gradients wing morphology echolocation and local landscape structure. Additionally, we examined bat functional groups in this region and compared them with those of three other arid regions of the world to identify potential similarities and differences. The southern African arid region hosted 17 bat species, representing eight families, Article history: of which three are endemic to the region (Rhinolophus denti, Laephotis namibensis and Cistugo Received: 14 March 2017 seabrae) and one is vagrant (the fruit bat Eidolon helvum). Species richness varied spatially Accepted: 21 October 2017 within this arid region, being highest in the drier but topographically heterogeneous Namib Desert, probably as a result of roost availability. With regards to functional groups, the southern African Acknowledgements arid region had few bat species adapted to foraging in open spaces, particularly when compared with We thank Maria João Ramos Pereira and Ludmilla Aguiar for the the neighbouring savannahs. Drawing from this study, we suggest that: a) despite species richness invitation to write this paper. We also thank two anonymous reviewers decreasing with increasing aridity at the sub-continental scale, at a more local scale landscape and Mar Cabeza for helpful comments. PJT acknowledges the financial support of the Department of Science features (e.g. habitat structure) might be more relevant than aridity in determining bat species and Technology and the National Research Foundation through the richness; and b) an unknown factor, possibly patterns of temperature limiting the availability of South African Research Chair on Biodiversity Value and Change hosted insects flying high above the ground, restricted the diversity of the open air foragers throughout the by University of Venda and co-hosted by the Centre for Invasion Biology. region. We highlight additional areas of research worth investigation. Introduction critical description of bat diversity patterns in this region, and examine The bat fauna of the African continent has been overlooked (Monadjem its bat functional groups, by comparing them with those of three et al., 2010; Herkt et al., 2016), especially when compared to, for other arid regions of the world, to identify potential similarities and example, that of Europe or North America (Walters et al., 2012; differences. At a large spatial scale, functional groups relate with major Dietz and Kiefer, 2016). The reasons for this are diverse and include abiotic gradients such as temperature, and humidity (McGill et al., challenges in conducting fieldwork, the lack of financial resources, and 2006), and will serve to identify macroecological patterns and therefore a dearth of relevant experts. This lack of knowledge is even greater provide direction for future ecological studies (Kearney et al., 2010). for the bat fauna of arid ecosystems that are often considered to have biodiversity less attractive than those of biodiversity hotspots (Durant Factors influencing patterns of bat diversity et al., 2012, 2014), since they typically host lower diversity and species At the global scale, bat diversity patterns follow the increase from of little conservation concern. However, arid areas are affected by higher to lower latitudes documented for a wide spectrum of taxonomic habitat degradation as a consequence of poor land use practices, and groups (Gaston, 2000), showing peaks in proximity of the Equator, are predicted to be significantly impacted by climate change and further as reported for both New World and African bat diversity (Tello and desertification in the near future (D’Odorico et al., 2013). Furthermore, Stevens, 2010; Ramos Pereira and Palmeirim, 2013; Herkt et al., arid ecosystems are expected to be less resilient to disturbance due 2016). Gradients in New World bat diversity correlate particularly to lower species richness and thus low redundancy within functional with environmental variables representing gradients in energy and groups (Millennium Ecosystem Assessment, 2005). It is therefore seasonality, especially for groups of species with broad distributions important to increase research effort on these arid ecosystems. We (Tello and Stevens, 2010). On the other hand, at smaller scales, propose that this process begins with a review of their biodiversity, various landscape features mediate bat diversity. Freshwater resources, which may act as a baseline for future work. To this end, we summarise which are often associated with more structurally complex vegetation, the knowledge that has been acquired over the past decades on the bat correlate with local high diversity (Monadjem et al., 2008; Fahr and fauna of the arid areas of southern Africa, as well as introduce new Kalko, 2011; Herkt et al., 2016), and this effect may be especially questions and topics for future research. In particular, we provide a marked for arid and semi-arid areas in which these resources are scarce (Monadjem et al., 2008; Cooper-Bohannon et al., 2016). Additionally, ∗Corresponding author moderately rugged terrain such as mountains and escarpments support Email address: [email protected] (Ara Monadjem) higher diversity (Schoeman et al., 2013; Herkt et al., 2016). All these Hystrix, the Italian Journal of Mammalogy ISSN 1825-5272 7th March 2018 ©cbe2018 Associazione Teriologica Italiana doi:10.4404/hystrix–00016-2017 Hystrix, It. J. Mamm. (2018) — online first features contribute to increase landscape heterogeneity and promote bat and Nama Karoo) are recognised as separate biomes (Rutherford and diversity providing rooting sites and/or suitable foraging habitat. Westfall, 1986), whereas the Kalahari, on account of its relatively high annual rainfall, is not considered a true desert, but rather an extremely Functional groups and habitat selection in bats dry savannah developed on Kalahari sands. As a consequence of this Bat species can be divided into three functional groups based on peculiarity, it harbours distinct vegetation associations (see Mucina and foraging niche (Schnitzler and Kalko, 2001; Monadjem et al., 2010; Rutherford, 2006). Denzinger and Schnitzler, 2013): open air foragers, background clutter (edge) foragers, and clutter foragers. This subdivision is based on Methods the adaptive complex between wing morphology and echolocation To describe patterns of species diversity within the arid region based (Aldridge and Rautenbach, 1987; Norberg and Rayner, 1987; Arita on reported records, bat distributions were extracted from Monadjem and Fenton, 1997) that broadly define where a bat roosts and forages, et al. (2010). All bat records falling within the arid region as described hence determining the habitat that can be selected. Open air foragers in Fig.