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Alan C. Kemp

Bio: Alan C. Kemp is an academic researcher. The author has contributed to research in topics: Falco rupicoloides & Medal. The author has an hindex of 6, co-authored 8 publications receiving 71 citations.
Topics: Falco rupicoloides, Medal, Nest, Plumage, Kestrel

Papers
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Journal ArticleDOI
01 Mar 1996-Ostrich
TL;DR: Kempe et al. as discussed by the authors investigated 56 active and 18 potential nest sites of the Southern Ground Hornbill Bucorvus leadbeateri in the Kruger National Park, South Africa over 298 nest-seasons during 1967-95.
Abstract: Summary Kemp, A. C. & Begg, K. S. 1996. Nest sites of the Southern Ground Hornbill Bucorvus leadbeateri in the Kruger National Park, South Africa, and conservation implications. Ostrich 67: 9–14. Details of 56 active and 18 potential nest sites of the Southern Ground Hornbill Bucorvus leadbeateri were recorded in the Kruger National Park, South Africa, over 298 nest-seasons during 1967–95. Nests were natural cavities with a median diameter of about 40 cm, 96% situated in 12 species of trees and 4% in rock faces. Only four species of tree provided 72% of nest sites and 85% of active nest sites were formed by rotting of a damaged branch or trunk. No habitat preference associated with nest sites was detected, but 61% of nests were within 400 m of a tourist road, possibly due to lower predation pressure. Nest attractiveness was correlated positively with nest height, cavity shallowness and proximity to tourist roads, but nest success was not correlated with any measured features of the sites. Average cavity d...

21 citations

Journal ArticleDOI
01 Jun 1991-Ostrich
TL;DR: Laying dates for a population of individually marked Greater Kestrels Falco rupicoloides near Pretoria, South Africa, were determined for 89 nesting attempts during 1975–1988.
Abstract: Summary Kemp, A C 1991 Timing of laying by Greater Kestrels Fulco rupicoloides near Pretoria, South Africa Ostrich 62: 35–39 Laying dates for a population of individually marked Greater Kestrels Falco rupicoloides, on grass- and croplands near Pretoria, South Africa, were determined for 89 nesting attempts during 1975–1988 Laying occurred in the austral spring between 23 July and 11 November Timing of laying was negatively correlated with rainfall of the previous summer and positively correlated with rainfall of the winter and spring preceding laying Success in fledging young was significantly higher for clutches laid before the median laying date of 1 September and for clutches laid after seasons of above average rainfall

14 citations

Journal ArticleDOI
01 Mar 2001-Ostrich
TL;DR: This work has been supported by the South African Department of Environmental Affairs and Tourism, the Namibian Ministry of Environment and Tourism and BirdLife South Africa.
Abstract: ACKNOWLEDGEMENTS L.G.U. acknowledges support from the National Research Foundation, Pretoria, and the University of Cape Town Research Committee. TB.O. and SAFRING are supported by the South African Department of Environmental Affairs and Tourism, the Namibian Ministry of Environment and Tourism and BirdLife South Africa. HD. Oschadleus and R.W Summers commented on an earlier draft; the referees, M. Herremans and P.J.Jones, suggested improvements.

11 citations

Journal ArticleDOI
01 Mar 1995-Ostrich
TL;DR: It remained high for both sexes when feeding nestlings and both made more strikes from hovers when breeding, especially females that also increased the number of bouts of hovering preceding a strike...
Abstract: Summary Kemp, A. C. 1995. A comparison of hunting behaviour by each sex of adult Greater Kestrels Falco rupicoloides resident near Pretoria, South Africa. Ostrich 66:21-33. During 1975–79,I observed the hunting behaviour of territorial, colour-marked, adult Falco rupicoloides that were resident on grass and croplands near Pretoria, South Africa. I recorded 686 strikes by males and 796 by females. Both sexes mainly hunted from perches or hovers and captured invertebrates 10 g. In monthly comparisons, both sexes made more and shorter strikes from perches when moulting and not breeding (December-May). They made more and longer strikes at vertebrate prey during courtship (June-August). When breeding (September-November), hunting success of males was highest when feeding the incubating female. It remained high for both sexes when feeding nestlings and both made more strikes from hovers when breeding, especially females that also increased the number of bouts of hovering preceding a strike...

10 citations

Journal ArticleDOI
01 Sep 1995-Ostrich
TL;DR: There was no correlation between pairs in occupancy of territory, productivity or development periods of young: this confirms the flexible breeding abilities of the Secretarybird Sagittarius serpentarius which are unusual for such a large bird.
Abstract: Summary Kemp, A. C. 1995. Aspects of the breeding biology and behaviour of the Secretarybird Sagittarius serpentarius near Pretoria, South Africa. Ostrich 66: 61–68. Secretarybirds in three adjacent territories were monitored from 1977 to 1988 on grass- and croplands near Pretoria, South Africa. Most observations of breeding biology and behaviour confirmed or extended previous studies. There was no correlation between pairs in occupancy of territory, productivity or development periods of young: this confirms the flexible breeding abilities which are unusual for such a large bird. Some aspects of breeding biology (egg shape and texture, watering of chicks) and behaviour (Wings open and Up-down greeting displays) may be homologous with storks and important in understanding the phylogeny and evolution of the Sagitariidae and other diurnal raptors.

9 citations


Cited by
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Book
01 Jan 1997
TL;DR: In this paper, a major work covering the breeding and non-breeding birds of the Southern African sub-region is presented, which sets new standards in its scope and in its methods, for setting a measured baseline against which to judge environmental trends across the great range of southern Africa.
Abstract: This is a major work covering the breeding and non-breeding birds of the Southern African sub-region. Published in two volumes, Volume One includes introductory chapters describing methodology and the 'avi'-geography of the region, with habitat photos, and coverage of the non-passerines, whilst Volume Two covers the passerines. Some 900 species are covered in total, including 200 vagrants, with detailed species accounts, maps and statistics for at least 500 species. Conservation issues are discussed for most species. '...sets new standards in its scope and in its methods...it will come to be valued ever more as years go by, for setting a measured baseline against which to judge environmental trends across the great range of southern Africa.' - Colin Bibby, "BirdLife International".

347 citations

Journal ArticleDOI
TL;DR: In this paper, it is suggested that Neogene marine transgressions flooded the peninsula in two areas and created circumstances leading to the biogeographical patterns of the present day, and more than half the species present in this region have species boundaries north of the Isthmus of Kra, at 11−13� N latitude.
Abstract: Aim The aim of this review is to contribute to our understanding of the origination of the Sundaic and Indochinese biotas in Southeast Asia. Numerous unsolved problems surround the origination of the differences between these biotas and the determinants of the breadth and current position of the transition between them. Location Literature reviews show that phytogeographical and zoogeographical transitions between the Sundaic and Indochinese subregions lie on the Thai–Malay peninsula just north of the Isthmus of Kra. A second, more widely recognized botanical transition lies 500 km further south at the Kangar–Pattani line near the Thai–Malay border. Results The phytogeographical transition involves 575 genera of plants, and a change from wet seasonal evergreen dipterocarp rain forest to moist mixed deciduous forest. The zoogeographical transition is best characterized for forest birds, and more than half the species present in this region have species boundaries north of the Isthmus of Kra, at 11–13� N latitude. Although the phytogeographical transition is climate-related today, and the avifaunal transition is viewed as being associated with the vegetation change, there is no obvious present day geological, physiographical or environmental feature to account for the origination of the provincial biotas. Similarly, known Neogene palaeoenvironmental changes on the tectonically stable peninsula, including those associated with periods of lower sea levels and the emergence of Sundaland, fail to account for either the origination of the provincial differences or the current position of the transition. Main conclusions Contrary to earlier palaeogeographical reconstructions, it is suggested that Neogene marine transgressions flooded the peninsula in two areas and created circumstances leading to the biogeographical patterns of the present day. The Vail global eustatic curve, supported by the oxygen isotope record, indicates that sea levels were c. 100 m above the present-day level during the early/middle Miocene (24–13 Ma) and again during the early Pliocene (5.5–4.5 Ma). Present topography suggests such high sea stands would have created 30–100-km wide seaways north and south of the Nakhon si Thammarat Range in the central peninsula (southern Thailand). Geological, palaeontological and phylogenetic evidence for such hypothetical seaways is scant (there have been no focussed searches) but does not preclude their occurrence. The role of such Neogene highstands in explaining present day biogeographical patterns in Southeast Asia and elsewhere requires assessment.

244 citations

Journal ArticleDOI
TL;DR: The RSR occupancy model appears to be an attractive choice for modeling occurrences at large spatial domains, while accounting for imperfect detection and spatial autocorrelation.
Abstract: Determining the range of a species and exploring species–habitat associations are central questions in ecology and can be answered by analyzing presence–absence data. Often, both the sampling of sites and the desired area of inference involve neighboring sites; thus, positive spatial autocorrelation between these sites is expected. Using survey data for the Southern Ground Hornbill (Bucorvus leadbeateri) from the Southern African Bird Atlas Project, we compared advantages and disadvantages of three increasingly complex models for species occupancy: an occupancy model that accounted for nondetection but assumed all sites were independent, and two spatial occupancy models that accounted for both nondetection and spatial autocorrelation. We modeled the spatial autocorrelation with an intrinsic conditional autoregressive (ICAR) model and with a restricted spatial regression (RSR) model. Both spatial models can readily be applied to any other gridded, presence–absence data set using a newly introduced R packag...

45 citations