Fenton P.D. Cotterill

Four New Bat Species (Rhinolophus hildebrandtii Complex) Reflect Plio-Pleistocene Divergence of Dwarfs and Giants across an Afromontane Archipelago

Gigantism and dwarfism evolve in vertebrates restricted to islands. We describe four new species in the Rhinolophus hildebrandtii species-complex of horseshoe bats, whose evolution has entailed adaptive shifts in body size. We postulate that vicissitudes of palaeoenvironments resulted in gigantism and dwarfism in habitat islands fragmented across eastern and southern Africa. Mitochondrial and nuclear DNA sequences recovered two clades of R. hildebrandtii senso lato which are paraphyletic with respect to a third lineage (R. eloquens). Lineages differ by 7.7 to 9.0% in cytochrome b sequences. Clade 1 includes R. hildebrandtii sensu stricto from the east African highlands and three additional vicariants that speciated across an Afromontane archipelago through the Plio-Pleistocene, extending from the Kenyan Highlands through the Eastern Arc, northern Mozambique and the Zambezi Escarpment to the eastern Great Escarpment of South Africa. Clade 2 comprises one species confined to lowland savanna habitats (Mozambique and Zimbabwe). A third clade comprises R. eloquens from East Africa. Speciation within Clade 1 is associated with fixed differences in echolocation call frequency, and cranial shape and size in populations isolated since the late Pliocene (ca 3.74 Mya). Relative to the intermediate-sized savanna population (Clade 2), these island-populations within Clade 1 are characterised by either gigantism (South African eastern Great Escarpment and Mts Mabu and Inago in Mozambique) or dwarfism (Lutope-Ngolangola Gorge, Zimbabwe and Soutpansberg Mountains, South Africa). Sympatry between divergent clades (Clade 1 and Clade 2) at Lutope-Ngolangola Gorge (NW Zimbabwe) is attributed to recent range expansions. We propose an “Allometric Speciation Hypothesis”, which attributes the evolution of this species complex of bats to divergence in constant frequency (CF) sonar calls. The origin of species-specific peak frequencies (overall range = 32 to 46 kHz) represents the allometric effect of adaptive divergence in skull size, represented in the evolution of gigantism and dwarfism in habitat islands.

Repeated trans-watershed hybridization among haplochromine cichlids (Cichlidae) was triggered by Neogene landscape evolution

The megadiverse haplochromine cichlid radiations of the East African lakes, famous examples of explosive speciation and adaptive radiation, are according to recent studies, introgressed by different riverine lineages. This study is based on the first comprehensive mitochondrial and nuclear DNA dataset from extensive sampling of riverine haplochromine cichlids. It includes species from the lower River Congo and Angolan (River Kwanza) drainages. Reconstruction of phylogenetic hypotheses revealed the paradox of clearly discordant phylogenetic signals. Closely related mtDNA haplotypes are distributed thousands of kilometres apart and across major African watersheds, whereas some neighbouring species carry drastically divergent mtDNA haplotypes. At shallow and deep phylogenetic layers, strong signals of hybridization are attributed to the complex Late Miocene/Early Pliocene palaeohistory of African rivers. Hybridization of multiple lineages across changing watersheds shaped each of the major haplochromine radiations in lakes Tanganyika, Victoria, Malawi and the Kalahari Palaeolakes, as well as a miniature species flock in the Congo basin (River Fwa). On the basis of our results, introgression occurred not only on a spatially restricted scale, but massively over almost the whole range of the haplochromine distribution. This provides an alternative view on the origin and exceptional high diversity of this enigmatic vertebrate group.

Why One Century of Phenetics is Enough: Response to “Are There Really Twice As Many Bovid Species As We Thought?”

1AEON—Africa Earth Observatory Network, Geoecodynamics Research Hub, c/o Department of Botany and Zoology, University of Stellenbosch, Stellenbosch 7602, South Africa; 2SARChI Chair on Biodiversity Value & Change in the Vhembe Biosphere Reserve & Core Member of Centre for Invasion Biology, School of Mathematical and Natural Sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa; 3Viale Liegi 48, 00198 Roma, Italy; 4 Department of Biological Sciences, University of Cape Town, Private Bag, Rondebosch 7700, South Africa; and 5School of Archaeology and Anthropology, Australian National University, Canberra 0200, Australia; ∗Correspondence to be sent to: E-mail: fcotterill@gmail.com

A recent inventory of the bats of Mozambique with documentation of seven new species for the country

The bat fauna of Mozambique is poorly documented. We conducted a series of inventories across the country between 2005 and 2009, resulting in the identification of 50 species from 41 sites. Of these, seven species represent new national records that increase the country total to 67 species. These data include results from the first detailed surveys across northern Mozambique, over an area representing almost 50% of the country. We detail information on new distribution records and measurements of these specimens. Special attention is paid to the Rhinolophidae, because these include several taxa that are currently in a state of taxonomic confusion. Furthermore, we also present some notes on taxonomy, ecology and echolocation calls. Finally, we combine modelled distributions to present predicted species richness across the country. Species richness was lowest across the coastal plain, to the east and far north, and is predicted to increase in association with rising altitude and higher topographic unevenness of the landscape.

Impacts of taxonomic inertia for the conservation of African ungulate diversity: an overview

We review the state of African ungulate taxonomy over the last 120 years, with an emphasis on the introduction of the polytypic species concept and the disciplines general neglect since the middle of the 20th century. We single out negative consequences of ‘orthodox’ taxonomy, highlighting numerous cases of neglect of threatened lineages, unsound translocations that led to lineage introgression, and cases of maladaptation to local conditions including parasitic infections. Additionally, several captive breeding programmes have been hampered by chromosome rearrangements caused by involuntary lineage mixing. We advocate that specimen‐based taxonomy should regain its keystone role in mammal research and conservation biology, with its scientific values augmented with genomic evidence. While integration with molecular biology, ecology and behaviour is needed for a full understanding of ungulate alpha diversity, we stress that morphological diversity has been neglected despite its tremendous practical importance for some groups of ‘utilizers’ such as trophy hunters, wildlife tourists and conservationists. We conclude that there is no evidence that purported ‘taxonomic inflation’ has adverse effects on ungulate conservation: rather, it is taxonomic inertia that has such adverse effects. We stress that sound science, founded on robust taxonomy, should underpin effective sustainable management (hunting, ranching, captive breeding and reintroduction programmes) of this unique African natural resource.

Species definitions and conservation: a review and case studies from African mammals

The nature of species, especially as applied to large mammals, is of major concern in conservation. Here, we briefly comment on recent thinking in alpha taxonomy, and assert that species are in essence evolutionary lineages, and that the most effective way of recognising them is by their diagnosability, i.e. the so-called Phylogenetic Species Concept. We further assert that the amount of genetic distance is not a relevant datum for distinguishing species, and that the ability to interbreed is not relevant. We consider a few case studies, especially that of the Northern White Rhinoceros Ceratotherium cottoni, and also species in Loxodonta, Giraffa and Oreotragus.

The Present Day Drainage Patterns of the Congo River System and their Neogene Evolution

Whilst the Congo Basin contains one of the world’s largest fluvial systems, little is known about the basin’s geomorphic evolution during the Cenozoic. The basin’s drainage patterns may provide insights into its geomorphic development during the Neogene. The juxtaposition of differing drainage patterns can be explained by the multi-stage evolution of the Congo Basin. The drainage pattern is influenced by several controls, such as lithology and tectonics, which dominate in some regions, with zones of overlap were controls inter-act. The evaluation of the drainage patterns in the context of the basin’s long wavelength geomorphology reveals a relative chronology of events. However, timings of key events are poorly known but evidence obtained using geoecodynamics constrains the ages of major river emplacements. The combination of geologic, geomorphic and phylogenetic data sheds light on the Neogene evolution of the Congo River System.

Victoria Falls: Mosi-oa-Tunya - The Smoke That Thunders

Victoria Falls are located on the Zambezi, southern Africa’s largest river. In full flood with a maximum vertical drop of 108 m, and length of 1,700 m, they form the world’s largest sheet of falling water. The Falls demarcate two sections of the Zambezi of contrasting geomorphology: the low gradient, broad channel of the Upper Zambezi and the steep gradient, narrowly incised downstream Batoka gorges, ∼100 km in length. The Victoria Falls represent the modern position of a west-migrating knickpoint that incised the lower gorges into Jurassic (Karoo-age) basalts that form the bedrock. Evolution of the Falls and lower Gorges was accompanied by deposition of Late Cenozoic sediments of the Victoria Falls Formation (VFF), which preserve a remarkable assemblage of hominin artefacts. This archaeological record provides a unique context to decipher how the Batoka gorges evolved through the Pleistocene; two contrasting estimates, obtained from these hominin artefacts, constrain estimates of headward erosion rates, westward, to between 0.042–0.052 m/year and 0.067–0.080 m/year. This faster rate means that headward erosion has incised 20 km of gorges below the Falls in 300–250 ka. The present position of the Victoria Falls reflects the culmination of evolutionary events initiated by diversion of drainage off the Kalahari plateau into the mid-Zambezi river that occupies a deep graben.