Browsing by Author "Bowie, Rauri Charles Kerr"

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    Birds, molecules, and evolutionary patterns among Africa's islands in the sky
    (2003) Bowie, Rauri Charles Kerr; Crowe, Timothy M
    Combing results from phylogenetic and population level studies suggests that climatic cycling has had a profound influence on montane bird speciation in Africa. The results from this thesis suggest that there is deep genetic divergence between many clades (8-12%) of montane passerine birds in Africa, with some shallow divergence towards the tips (4-6%). For widespread species reciprocal monophyly has not been reached in some instances, but generally there is some support for the refuge idea that isolation (fragmentation) of montane forests has facilitated speciation. However, most speciation events happened well before the Pleistocene and therefore the Pleistocene Refugia Hypothesis is not appropriate as a model with which to explain patterns of montane bird diversification in Africa. Rather, both dispersal and vicariance have played important roles in shaping montane bird communities. Thus, a refugia type model does work, but only within the context of pulsed or cyclic expansion and contraction of montane forests, supported in thus study by the consistent recovery of spatially structured areas of endemism, despite varying temporal dynamics.
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    Faunal turnover between east and southern African terrestrial vertebrates: is Malawi the geographical break?
    (2014) Kaliba, Potiphar Menaheim; Bowie, Rauri Charles Kerr; Crowe, Timothy M
    The study centred on the investigation of phylogeographic structure within three forest associated bird species and two small mammal species, as well as two woodland associated bird species distributed across the Malawi Rift of Africa. The key objective was to investigate the extent to which geographically structured lineages exist within several bird (Stripe-cheeked Greenbul Andropadus milanjensis, Malawi Batis Batis dimorpha, Bar-throated Apalis Apalis thoracica, Southern Puffback Dryoscopus cubla and White-browed Robin- chat Cossypha heuglini) and small mammal species (Delectable Soft-furred Mouse Praomys delectorum and Dark-coloured Brush-furred Rat Lophuromys aquilus) distributed across the Malawi Rift. Analyses of a combination of mtDNA (1041 bp ND2 in birds, and 1130-1143 bp Cytochrome-b and 461-466 bp control region in mammals) and nDNA (463-481 bp CHDZ, 569-572 MUSK and 594 bp TGFb2 in birds, and Beta-Fibrinogen intron- 7 in small mammals) revealed significant population structure in each of the five forest associated species studied. In contrast, woodland associated birds exhibited reduced spatial genetic structure across the Malawi Rift. Collectively the result suggest that phylogeographic breaks for forest associated species occur in the southern highlands separating Mount Namuli in Mozambique and Mount Mulanje as well as between Mount Mulanje and Mount Zomba in Malawi; in the central highlands that split Malawi into two halves, and within the northern highlands separating the Misuku Hills and Nyika Plateau. The Misuku Hills are also separated from the Udzungwa Mountains of the Eastern Arc and volcanic Mount Rungwe in Tanzania. Genetic differences exhibited by the taxa investigated across the phylogeographic breaks and degree of lineage turnover revealed in the small mammals support observations by Vrba (1985) based on fossil mammal assemblages that Malawi may be geographically key to understanding faunal turnover between southern and east African animal taxa. The detected phylogeographic breaks primarily occur in forest reserves that are not adequately protected with the exception of Nyika National Park. Illegal logging and uncontrolled fires are threatening the montane ‘sky islands’ population, thus compromising the conservation of the fauna and important evolutionary distinct units.
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    Taxonomy and phylogeny of red-tailed francolins (Genus Peliperdix)
    (2003) Nangammbi, Tshifhiwa Constance; Crowe, Timothy M; Bowie, Rauri Charles Kerr
    The Red-tailed Group of francolins falls within the class Aves, order Galliformes, family Phasianidae and genus Peliperdix. These are small francolins consisting of three putative species (Peliperdix coqui, P. albogularis and P. schlegelii) that are largely allopatric. Two species (P. coqui and P. albogularis) are considered to be polytypic species, but is a large discrepancy in the number of subspecies attributed to P. coqui and P. albogularis. The mitochondrial cytochrome b gene, organismal characters and combined data were used to identify diagnosable taxa, test the monophyly and reconstruct the phylogeny of the Red-tailed Group. Sixteen exemplars of the Red-tailed Group (representing all species and nearly all subspecies currently recognised in the genus Peliperdix) from different geographical localities were studied. Maximum likelihood (cyt b), maximum parsimony (cyt b, organismal, combined) , distance analysis (cyt b) were performed to resolve the phylogenetic relationships among them. The trees obtained from DNA sequence, organismal and combined data were incongruent in respect to the position of some taxa. The monophyly of the Red-tailed Group seems to be well supported, but the identity of, and interrelationships between the subspecies and species are less well resolved. The morphological and combined tree probably reflects the taxon phylogeny better than the tree based on mitochondrial DNA. only. The most remarkable result that is strongly supported by both organismal and combined trees was that they bring clear resolution between P. albogularis and P. schlegelii as two separate species from P. coqui. Due to the short number of DNA sequences obtained, one cannot make a decision as to whether the subspecies should be elevated to species. Finally, it is suggested that more systematic studies must be done based on multiple independent data sets in order to obtain a robust taxonomy and phylogeny for this group.
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    Taxonomy, phylogenetic and biogeographical relationships of African grassland Francolins (Genus: Scleroptila)
    (2003) Mandiwana, Tshifhiwa G; Crowe, Timothy M; Bowie, Rauri Charles Kerr
    The potential for using a combination of molecular and whole-organismal data has opened up new avenues for avian taxonomy, phylogenetics and biogeography. Such a multifaceted approach is used here to identify diagnosable taxa within the Orange River Francolin Scleroptila levaillanloides species complex and resolve evolutionary relationships between these taxa and other mono-and polytypic forms within the Red-winged Group of francolins (= genus Scleroplila sensli lalo). Mitochondrial cytochrome-b DNA sequence data (±250 b.p.) from 50 individuals and 19 morphological characters extracted from reports in published literature were employed to achieve these aims. These characters were analysed separately and also in combination using maximum parsimony (DNA sequences and organismal data), maximum likelihood (DNA sequences) and distance (DNA sequences) analyses. Monophyly of the Red-winged Group plus the Ring-necked Francolin Dendroperdix slreptophorus was supported by all the analyses (bootstrap support ranged from 50%-94%) except distance analysis. The Orange River Francolin complex was found to be non-monophyletic. Two distinct clades were identified, one comprising taxa from southwestern and the other from northeastern Africa. Morphological analysis yielded a distinct clade of the southwestern Orange River Francolin. The other polytypic species and assemblages thereof show poor resolution. The results of this study clearly demonstrate a need for further assessment of the taxonomic status of Scleroptila spp. and their phylogenetic relationships.
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    Taxonomy, phylogeny and biogeography of cisticolas (Cisticola spp.)
    (2015) Davies, Owen R; Crowe, Timothy M; Bowie, Rauri Charles Kerr
    A review of the genus Cisticola was published in 1930 by Rear-admiral Lynes. While subsequent authors have modified Lynes' original groupings, his work remains the basis for modern syntheses of cisticolas. This study tests Lynes' hypotheses by analysing data that he presented in his review and with measurement and plumage data collected from museum specimens. Lynes' groupings were well recovered (98%) when data captured from his review were analysed phenetically, suggesting that he grouped species mostly by similarity. In contrast, when morpho-behavioural data were analysed using cladistic methods, many of his groupings were not monophyletic and the resultant cladogram had very little nodal support due to their highly conservative morphology. To resolve the structure of the genus and the relationships within it, two mitochondrial and four nuclear regions were sequenced from toe-pad samples taken from museum specimens. The molecular analyses included 44 of the 49 currently recognised species and represents the most taxon-dense molecular phylogeny of the genus. The resultant phylogeny separates species into five main clades, but many of Lynes' groupings were not monophyletic and there was also very little support for more recent groupings. Vocalisation analyses indicated that frequency components of songs were correlated with habitat type and body size. These correlations, though, disappeared when phylogeny was controlled for indicating that phylogenetic history rather than habitat preference influenced song character distribution. Some song types are mismatched to their environment, and some sympatric sister species appear to give similar calls. Cisticolas may overcome these attenuation and identification difficulties with behavioural adaptations and aerial displays. The biogeographic distribution of closely related species does not agree with many of the previously proposed hypotheses and a dated phylogeny estimates that most of the diversification in the genus has occurred within the last five million years. Most of the mean divergence date estimates correlated with periods of climate variability and episodes during which there is evidence for high lake levels in Africa, rather than correlating with Plio-Pleistocene glaciation, offering evidence that open habitats may have become fragmented during extremes of both arid and humid climates.
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    Taxonomy, phylogeny and biogeography of francolins ('Francolinus' spp.) Aves: Order Galliformes, Family Phasianidae
    (2014) Mandiwana-Neudani, Tshifhiwa Gift; Crowe, Timothy M; Bowie, Rauri Charles Kerr
    Francolins (Francolinus spp.) are small to medium-sized, sedentary, Old World, partridge/quail-like, terrestrial gamebirds (Order Galliformes) that occupy diverse habitats ranging from dry/open/scrubby lowland and montane grasslands, bushveld and savanna/woodland to mesic montane/lowland forests and forest edges. Some francolins have complex distribution patterns and also are morphologically, ecologically and behaviourally diverse. At the start of this research, Francolinus Stephens, 1819 was considered a monophyletic galliform genus comprising 41 species (36 African and five Asiatic) divided among eight putatively monophyletic species groups and four taxonomically enigmatic species. However, different taxonomic revisions, especially post Hall's (1963) classic monograph, challenged the monophyletic status of the genus and that of some of its designated species groups differed markedly in the number of recognized subspecies. Furthermore, there was debate concerning the geographical origin of the genus: Asia versus Africa. Some of the early molecular research on a few exemplar francolin species based on partial mitochondrial Cytochrome-b DNA sequences and Restriction Fragment Length Polymorphisms (RFLPs) also challenged the monophyly of the genus and that of some of Hall's (1963) species groups. These findings suggested that francolins may form at least two distantly related lineages called 'patryse' (partridges) and 'fisante' (pheasants) by Afrikaans-speaking people. Patryse, or 'true' francolins, had been divided into as many as five genera (Francolinus, Ortygornis, Dendroperdix, Peliperdix, Scleroptila) and fisante, or spurfowls, all grouped into a single genus, Pternistis. Research in this thesis is based on: mitochondrial and nuclear DNA sequences (5554 base pairs), organismal and vocal characters of francolins and spurfowls.