Читать книгу Bats of Southern and Central Africa - Ara Monadjem - Страница 10

Until recently, two suborders of bats were recognised –the larger Old World fruit-eating Megachiroptera (commonly called megabats), and the smaller, predominantly insect-eating Microchiroptera (commonly called microbats). However, recent molecular findings, reviewed by Hutcheon and Kirsch (2006), provide compelling evidence for a close alliance between Old World fruit bats (Pteropodidae) and certain families traditionally placed in the Microchiroptera (Figure 3). They suggested the names Pteropodiformes (alternatively also known as Yinpterochiroptera, e.g. Teeling et al. 2005) for this newly defined suborder and Vespertilioniformes (Yangochiroptera) to accommodate the remaining microbat families. We follow this classification here and list five southern African bat families within Pteropodiformes: Pteropodidae, Hipposideridae, Rhinolophidae, Rhinonycteridae and Megadermatidae. We place all other southern African families in the suborder Vespertilioniformes, and hence have done away with the micro- and megabat distinction. Nevertheless, in this book we often use the terms ‘microbats’ and ‘megabats’ to refer to the older classification with which so many readers are still most familiar. We prefer the names Pteropodiformes and Vespertilioniformes over Yinpterochiroptera and Yangochiroptera, because the first two names are informative, indicating the species membership of the respective suborders. Considering the active research in chiropteran genomics, we can look forward to new molecular evidence continuing to refine our understanding of the diversity of these mammals (Teeling et al. 2018).

Figure 3. A phylogenetic tree depicting the evolutionary relationships among the principal clades of living bats. It presents the combined evidence of four DNA markers (selected gene sequences). This phylogeny structures the systematic layout of this book (after Eick et al. 2005). The number of asterisks indicates the level of ‘statistical confidence’ placed in particular nodes. Arrows indicate the number of insertions or deletions of nucleotides unique to particular nodes.

We follow Eick et al. (2005) and Miller-Butterworth et al. (2007) in recognising Miniopteridae to be a distinct family and not a subfamily of Vespertilionidae as accepted until recently. Since the first edition of our book, two other families have become widely accepted for existing genera; we now also recognise the families Cistugidae (with a single genus, Cistugo) (Lack et al. 2010) and Rhinonycteridae (with the genera Triaenops and Cloeotis) (Foley et al. 2015).

In the first edition of our book, we reported a total of 116 bat species that had been recorded within the southern African region and, with one exception, all were treated in separate species accounts. The exception, Mormopterus acetabulosus, is known from the region by a single specimen collected in the 1830s or 1840s in Port Natal (Durban), South Africa. This species occurs in Mauritius and its presence in southern Africa is doubtful. The Durban specimen was possibly translocated on a ship, or may have been a vagrant individual. No other material evidence supports its occurrence in the region. Consequently, we omitted M. acetabulosus from the species accounts in the first edition.

We also made this statement in 2010: ‘The total number of known species is likely to increase as new species are discovered. Moreover, pending further investigation, several species groups are likely to be split in the future.’ In the decade between the publication of the first and second editions, nine species of bats have been newly described or recognised and thus added to the regional fauna. These include seven species of Rhinolophus (R. cohenae, R. gorongosae, R. mabuensis, R. mossambicus, R. rhodesiae, R. smithersi and R. willardi), Miniopterus mossambicus and Kerivoula cf. phalaena (Taylor et al. 2012, 2018a, Monadjem et al. 2010a, 2013a, Taylor et al. 2019a). In addition, an undescribed (but well-known) species was only described formally, and thus named, some five decades after first being captured. In the first edition, we referred to this bat as Neoromicia cf. melckorum. It is now known as Neoromicia stanleyi (Goodman et al. 2017).

Over the past two decades, taxonomic revisions have split up many species of African bats. Phylogenetic revisions underpin these discoveries by refining the relationships among species and genera. The rapid pace of continuing taxonomic changes in Chiroptera is exemplified by the new changes in our understanding of the diversity of the African vespertilionids (see Family Vespertilionidae), made possible by new molecular data (Taylor et al. 2019a). This recent molecular work has also demonstrated deep divisions within the highly speciose genus Hipposideros. We recognise the genus Macronycteris for the large species within the commersoni group (M. vittatus and M. gigas within our region); the other newly recognised genus, Doryrhina, does not occur within our region (Foley et al. 2017; but see Hipposideridae introduction).

Recent taxonomic work also necessitated moving species from one genus to another; for example, the genus Lissonycteris was shown to be embedded within Myonycteris, hence L. angolensis and L. goliath are now known as M. angolensis and M. goliath (Nesi et al. 2013), and Epomops dobsonii in fact belongs in the genus Epomophorus (Almeida et al. 2016).

Many other changes are due to splitting geographically widespread species; for example, Rhinolophus landeri is now restricted to regions beyond southern Africa, with the local population recognised as R. lobatus (Taylor et al. 2018a). Similarly, R. hildebrandtii sensu stricto is now known to be restricted to East Africa, with the four newly described species R. mabuensis, R. mossambicus, R. smithersi and R. cohenae (all previously lumped within R. hildebrandtii) occurring in our region (Taylor et al. 2012).

In summary, the rapid rate of new discoveries in the African Chiroptera shows no sign of slowing down. It exemplifies the ‘New Age of Discovery’ of biodiversity (see Donoghue and Alverson 2000) that continues to transform our understanding of the evolving biosphere in the Anthropocene (Lewis and Maslin 2015, Voigt and Kingston 2016)

We have removed Nycteris vinsoni from the southern African list, as we do not consider it a valid species (see the species account for Nycteris macrotis). A paper by Riccucci and Lanza (2008) pointed out that as the genus name Neoromicia is feminine, the species name ‘nanus’ (which is masculine) should be corrected to the feminine form, ‘nana’; all species names in this genus are affected similarly.

Unless otherwise stated, we follow the nomenclature of scientific and common names of Simmons (2005). Annual updates on the classification of African bats are given in the latest version of the African Chiroptera Report (ACR 2018), a valuable resource for anyone interested in the biology and diversity of African bats.