The timing of moult in males and females of the monomorphic Pale-winged Starling Onychognathus nabouroup
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Hausberger, Martine , Henry, Laurence
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443805 , vital:74155 , https://hdl.handle.net/10520/EJC177689
- Description: Pale-winged Starlings Onychognathus nabouroup inhabit the arid western interior of southern Africa and moult-breeding overlap may occur. We collected field data in two successive years on the moult of individual birds, whose sex was confirmed by genetic techniques. Small samples revealed a non-significant tendency for the moult of females in the early stages of wing moult to be more advanced than that of males in both years, but also clear evidence that the starting date of moult differed in the two years. In this species the moult schedule may thus be variable at both the individual and the population levels.
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- Date Issued: 2015
Adaptations in primary wing moult of southern African Viduidae and their hosts (Estrildidae)
- Authors: Bonnevie, Bo T , Oschadleus, Hans-Dieter
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447691 , vital:74667 , https://doi.org/10.2989/00306525.2012.691910
- Description: Primary wing moult patterns in southern African brood-parasitic viduines were compared with those of their estrildid hosts. We searched for similarities in the timing and duration of moult within these closely related species potentially arising from their linked breeding biology and geographical distributions. Contrasting patterns were found between summer and winter rainfall regions, suggesting that climate dominates over phylogenetic effects on moult. Within the summer rainfall region different patterns of moult also emerged, and these generally supported the colonisation hypothesis of the host–brood parasite system. Moult estimates are provided for these taxa for which, until now, data have been mostly descriptive.
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- Date Issued: 2012
Geographic variation in the trophic ecology of an avian rocky shore predator, the African black oystercatcher, along the southern African coastline
- Authors: Kohler, Sophie A , Connan, Maëlle , Hill, Jaclyn M , Mablouké, Cécile , Bonnevie, Bo T , Ludynia, Katrin , Kemper, Jessica , Huisamen, Johan , Underhill, Leslie G , Cherel, Yves , McQuaid, Christopher D , Jaquemet, Sébastien
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444576 , vital:74252 , https://doi.org/10.3354/meps09215
- Description: The reflection of baseline isotopic signals along marine food chains up to higher trophic levels has been widely used in the study of oceanic top predators but rarely for intertidal predators. We investigated variation in the δ 13 C and δ 15 N ratios of a sedentary, rocky shore predator, the African black oystercatcher Haematopus moquini, over~ 2000 km of the southern African coastline, which is characterized by strong biogeographic patterns in primary productivity and intertidal communities. Blood and feathers from breeding adults and chicks and muscle tissues from primary prey items (mussels and limpets) were sampled between southern Namibia and the southeast coast of South Africa. 15 N enrichment was observed between the southeast and west coasts in oystercatcher tissues and their prey, mirroring an isotope shift between the oligotrophic Agulhas Current on the east coast and the eutrophic Benguela upwelling system on the west coast.
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- Date Issued: 2011
A re-evaluation of morphological differences in the Karoo Thrush Turdus smithi–Olive Thrush Turdus olivaceus species complex
- Authors: Wilson, J W , Symes, C T , Brown, M , Bonnevie, Bo T , de Swardt, D H , Hanmer, D
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447680 , vital:74666 , https://doi.org/10.2989/OSTRICH.2009.80.3.7.970
- Description: There is confusion in the literature concerning the taxonomic status of the Turdus smithi—T. olivaceus species complex. Here we attempt to clarify morphological differences within this complex. In addition, we attempt to clarify identification of the respective taxa. Although mean measurements of morphometric features differed significantly between species and subspecies, these features are not useful in separating species or subspecies due to considerable overlap in measurements. Furthermore, there were often larger differences between subspecies of T. olivaceus (particularly the geographically isolated T. o. swynnertoni) than between T. olivaceus and T. smithi. We therefore suggest that further work investigates the elevation of T. o. swynnertoni to full species status. Plumage characteristics proved more useful in separating T. olivaceus and T. smithi in the field, except in regions where the distributions overlap (potential hybridisation zones). We highlight the importance of clarifying the delineation of separate species particularly with respect to bird census data (e.g. Southern African Bird Atlas Project 2) and studies related to these species.
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- Date Issued: 2009
Additional morphological characteristics of Olive Thrushes and Karoo Thrushes
- Authors: Bonnevie, Bo T , Craig, Adrian J F K , Hulley, Patrick E
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447712 , vital:74669 , https://www.tandfonline.com/doi/pdf/10.2989/00306520409485415
- Description: A southern race of the Olive Thrush, Turdus olivaceus smithi Bonaparte, has recently been proposed as a full species, the Karoo Thrush Turdus smithi (Bowie et al. 2003). Some of the published information on the Olive Thrush Turdus olivaceus olivaceus thus pertains to the Karoo Thrush (eg Kopij 2000), whereas other information deals specifically with the Olive Thrush (eg Winterbottom 1966, Bonnevie et al. 2003). We have ringed, recaptured and recovered both Olive and Karoo Thrushes in the Eastern Cape since 1986, and the two taxa are markedly different in this region. We describe some differences in appearance of the two populations from these data, and compare mass and wing length of living birds, as well as culmen and tarsus lengths of museum specimens from the East London Museum, South Africa. The collection sites of the museum specimens were mapped using ArcView 3.1 (ESRI 1996) together with the ringing sites (Figure 1). Areas of potential sympatry are Oudtshoorn (33 25’S, 22 11’E) and Patensie (33 45’S, 24 48’E).
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- Date Issued: 2004