Urban tolerance data for African insectivorous bats
Marsden, Genevieve; Vosloo, Dalene; Schoeman, M. Corrie (2023), Urban tolerance data for African insectivorous bats, Dryad, Dataset, https://doi.org/10.5061/dryad.k3j9kd5b9
With increasing urbanization, particularly in developing countries, it is important to understand how local biota will respond to such landscape changes. Bats comprise one of the most diverse groups of mammals in urban areas, and many species are threatened by habitat destruction and land use change. Yet, in Africa, the response of bats to urban areas is relatively understudied. Therefore, we collated data on urban presence, phylogenetic relationship, and ecological traits of 54 insectivorous bats in Africa from available literature to test if their response to urbanization was phylogenetically and/or ecologically driven. Ancestral state reconstruction of urban tolerance, defined by functional group and presence observed in urban areas, suggests that ancestral African bat species could adapt to urban landscapes, and significant phylogenetic signal for urban tolerance indicates that this ability is evolutionarily conserved and mediated by pre‐adaptations. Specifically, traits of high wing loading and aspect ratio, and flexible roosting strategies, enable occupancy of urban areas. Therefore, our results identify the traits that predict which bat species will likely occur in urban areas, and which vulnerable bat clades conservation efforts should focus on to reduce loss of both functional and phylogenetic diversity in Africa. We, additionally, highlight several gaps in research that should be investigated in future studies to provide better monitoring of the impact urbanization will have on African bats.
We compiled a list of all mainland African insectivorous bat species using ACR (2018), Kingdon (2013), and Monadjem et al. (2020). We collected aspect ratio, wing loading, peak echolocation frequency, roost ecology, and functional group data for each of these species from these sources and other available literature (ACR., 2018; Aldridge & Rautenbach, 1987; Kingdon, 2013; Monadjem et al., 2020; Norberg & Rayner, 1987; Salsamendi et al., 2005). Available ecological trait data and presence in the phylogenetic super‐tree (Jones et al., 2005) reduced our data set from an initial 219 species to 54 species for statistical analyses. We then determined whether these species were present in urban (including suburban or peri‐urban) areas within their range (personal communication P. Webala, I. Tanshi and M.C. Schoeman; and Ancillotto et al., 2015; Andreani et al., 2019; Dekker et al., 2013; Fenton et al., 2002; Geldenhuys et al., 2013; Hoye & Spence, 2004; Jacobs & Barclay, 2009; Kurek et al., 2020; Lane et al., 2022; Legakis et al., 2000; O'Malley et al., 2020; Roswag et al., 2019; Schoeman, 2016; Schoeman & Waddington, 2011; Taylor et al., 1999; Wojtaszyn et al., 2013) and recorded this information as presence (1) or absence (0) in urban areas. We categorized roost specificity for each species as: utilizing 1 roost type = high, 2 roost types = medium, and ≥3 roost types = low. Each of the following was considered a different roost “type”: caves and mines, tree crevices (behind bark and tree holes), foliage, rock crevices, exposed outer walls of houses/buildings, roofs of houses/buildings, and road culverts. Roost specificity was classified regardless of the surrounding habitat type (e.g., open vs. narrow space) or landscape (e.g., highly urbanized vs. more rural areas) where the roost was found.
We categorized bats into urban exploiters, adapters, or avoiders after Jung and Kalko (2011) and Schoeman (2016) based on wing morphology and roost habits. Urban exploiters are open‐air bats with high wing loading and aspect ratios and highly flexible roost habits that readily use anthropogenic resources; urban adapters are narrow‐edge space bats with intermediate wing loading and aspect ratios, and fairly flexible roosting habits; and urban avoiders are narrow‐space bats with restricted roosting requirements, such as obligate cave roosters (Jung & Kalko, 2011; Schoeman, 2016).