GONZALEZ KIRCHNER, J. P. (2004)
Habitat preference of the Preuss's guenon (Cercopithecus preussi), on Bioko island, Equatorial Guinea.
Human Evolution: 19, Artikelnummer: 239 (2004)
Abstract:
The Press's guenon (Cercopithecus preussi) is considered to be one of the most threatened African primates. There is little information on the ecology and status of this primate on Bioko island, where it is found in the form of an endemic subspecies. The Press's, guenon shows preference for the Schefflera forest and the mountain habitat on Bioko island. As on the mainland they also have semitterrestrial habits and are found usually at the understorey of the forest. Competitive exclusion between this guenon and other guenon species could be an explanation of these ecological preferences. Habitat use and vertical stratification of the activity in the forest canopy seem to reduce competition with other sympatric primate species that inhabit on the island. Habitat destruction, and isolation in a reduced habitat, show to be the major threats for the survival of this primate on Bioko island.
gonzalez-biblio
VASEY, N. (2000)
Niche separation in Varecia variegata rubra and Eulemur fulvus albifrons: I. Interspecific patterns.
American Journal of Physical Anthropology 112 (3): 411-431
https://doi.org/10.1002/1096-8644(200007)112:3<411::AID-AJPA10>3.0.CO;2-R
Kurzfassung:
Niche separation was documented in a year‐long study of Varecia variegata rubra and Eulemur fulvus albifrons on the Masoala Peninsula, Madagascar. Feeding trees were measured, and diet, forest height, and forest site were recorded at 5‐min time points on focal animals. For time point data, multivariate and bivariate analysis of frequencies was employed to examine how niche dimensions vary between species according to sex, season, and reproductive stage. V. v. rubra feeds in larger trees than E. f. albifrons. V. v. rubra has a diet consisting mainly of fruit, whereas E. f. albifrons has a more varied diet. V. v. rubra ranges mainly above 15 m in tree crowns, whereas E. f. albifrons ranges mainly below 15 m in a wide array of forest sites. Both species are largely frugivorous, but they harvest fruit in different‐sized trees, in different quantities, and in different forest strata. Niche partitioning varies in tandem with seasonal shifts in climate and food availability and with reproductive stages. Seasonal shifts in forest site and forest height use are largely attributed to species‐specific tactics for behavioral thermoregulation and predator avoidance. The diet of E. f. albifrons is diverse whether examined by season or reproductive stage. However, females of both species diversify their diets with more low‐fiber protein than males during gestation, lactation, and the hot seasons. This pattern is most pronounced for V. v. rubra females and may be directly attributed to high energetic investment in reproduction. These results suggest that niche partitioning may be driven more by the energetic requirements of reproductive females than males.
vasey-biblio
BOSHOFF, A. F., PALMER, N. G., AVERY, G., DAVIES, R. A. G. & JARVIS, M. J. F. (1991)
Biogeographical and Topographical Variation in the Prey of the Black Eagle in the Cape Province, South Africa.
Ostrich 62: 59-72.
Summary:
Prey remains collected at or near Black Eagle Aquila verreauxii nest sites in the Cape Province, South Africa, were analysed according to frequency of occurrence of prey species in the samples. A total of 5748 prey individuals, collected from 73 sites, was analysed according to three biome groups and four nest site types. The Rock Hyrax Procavia capensis is the dominant prey species, but the eagles' diet spectrum varies according to its availability. Indices of species richness and diversity of the prey are inversely correlated with the proportion of the prey contributed by P. capensis, which in turn is determined by topography and vegetation. Biome has a greater influence on the indices than has nest site type. The age structure of the P. capensis prey remains closely reflects the juvenile:sub-adult:adult ratios in the biomes and at the nest site types. Medium-sized (approx. 1-4,5 kg) prey is usually taken. Juvenile domestic small-stock (lambs and goat kids) comprised only 3,4% of the overall total.
boshoff-biblio
OKES DU TOIT, J. C., O'CONNOR, T.G. & VAN DEN BERGAC, L. (2015)
Photographic evidence of fire-induced shifts from dwarf-shrub- to grass-dominated vegetation in Nama-Karoo.
South African Journal of Botany 101 (November 2015): 148-152. https://doi.org/10.1016/j.sajb.2015.06.002
Abstract:
The Nama-Karoo is a semi-arid inland biome in South Africa dominated by dwarf shrubs with grasses, shrubs, geophytes and herbs at varying levels of abundance. The position of the Nama-Karoo/grassland boundary is determined in part by rainfall amount, and in recent years there has been an increase in grassiness, correlated with good rains. This has allowed wildfires, an unusual occurrence, to burn at several sites in the central and eastern regions of the biome. The general effect of fire has been to convert dwarf shrublands to grassland with the extirpation of several nonsprouters species. A collection of photographs describes this effect. It is anticipated that these nonsprouters will recolonise by seed over time, but could be eliminated if fire frequency is high enough to eliminate their seedbank. It is predicted that if grassy conditions persist in the Nama-Karoo, then fire will be an important factor that shapes the Nama-Karoo/grassland boundary.
okes-biblio
SEAMAN, M. T., ASHTON, P. J. & WILLIAMS, W. D. (1991)
Inland salt waters of southern Africa.
Hydrobiologia 210, Artikeln Nr.: 75. https://doi.org/10.1007/BF00014324
Zusammenfassung:
Inland salt lakes are widely distributed in southern Africa: they are particularly common in South Africa, but many occur in Namibia and Botswana. All are shallow, and most are ephemeral with salinities that are not very high (mostly < 50 g l−1). Fringing zones of halophytes or submerged macrophytes are neither well-developed nor taxonomically diverse. The Cyanobacteria, especially Nodularia spumigena, often dominate the phytoplankton. The fauna of the Makgadikgadi area (northeast Botswana) is diverse and is similar to that of East African salt lakes. The aquatic fauna of salt water south of the Makgadikgadi Basin, on the other hand, is extremely depauperate, has no well-defined assemblage confined to saline waters, and appears mostly to comprise tolerant freshwater forms. Lovenula falcifera and Metadiaptomus transvaalensis (diaptomid copepods), Moina micrura (Cladocera) and Brachionus plicatilis (Rotifera) are frequently encountered zooplankton species, a few species of insects (Anisops sp., beetles, chironomids and ephydrids) are the principal non-planktonic macroinvertebrates. Artemia ‘salina’ is occasionally present, but may be an introduced form. The avifauna, in contrast to the aquatic macroinvertebrate fauna, is rich, with the greater and lesser flamingo often common.
seaman-biblio
NEL, J. A. & SOMERS, M. J. (2007)
Distribution and habitat choice of Capeclawless otters, Aonyx capensis, in South Africa.
African Journal of Wildlife Research 37 (Apr 2007): 61-70. DOI: 10.3957/0379-4369-37.1.61
Zusammenfassung:
Cape clawless otters, Aonyx capensis, are widely distributed in South Africa, as elsewhere on the continent. They occur in a wide variety of environments and most aquatic habitats, from freshwater lakes to the marine littoral,and even in episodic rivers in arid areas, provided freshwater sources are adequate and sufficient food is available. This animal is not much affected by turbid water as it locates prey by touch, and usually forages close to shores or banks. Evidence of presence in given localities and habitats, distributed over a large area of the Northern, Western, and Eastern Cape provinces, was deduced from signs (faecal deposits or distinctive tracks) on land. Accepting the inherent pitfalls of this approach we nevertheless feel using it is acceptable for a first approximation of habitat preferences over a large geographical area. Results point to areas with dense reed beds and a rocky substrate on banks being used most intensively, probably on account of a localized high food biomass.
nel-biblio
DENNIS, N., KNIGHT, M. & JOYCE, P. (1997)
The Kalahari: Survival in a Thirstland Wilderness.
168 Seiten, durchgehend farbig illustriert,
Struik Publishers, Cape Town. ISBN 10: 1868720195 ISBN 13: 9781868720194
Synopsis:
This work captures the essence of the Kalahari Gemsbok National Park in South Africa, from the smallest insects to its largest inhabitants. Photographed in all seasons of the year, the varying moods of the Kalahari are portrayed. The text aims to provide an insight into the balance of nature and the intricacies of life and survival in this wilderness.
dennis-biblio
GOMPPER, M. E. (2009)
Population ecology of the white‐nosed coati (Nasua narica) on Barro Colorado Island, Panama.
Journal of Zoology 241(3): 441-455
https://doi.org/10.1111/j.1469-7998.1997.tb04836.x
Abstract:
The white‐nosed coati, Nasua narica, is a common Neotropical carnivore with a social structure of band‐living adult females and solitary adult males. A coati population on Barro Colorado Island, Panama, was studied over a four‐year period by mark‐recapture, radiotelemetry. and direct observation of habituated individuals. The population density was approximately 51.5 individuals/km2 and the sex ratio was 1:1. Band size varied from six to 26 individuals (mean = 15.3) with extensive fluctuation within and between years. Mean foraging group size was smaller (7.2 individuals) than population group size, and fluctuated with food availability, synchronous parturition, and the emigration of mature males. Mean home‐range size of six bands was 0.33 km2, and ranges of adjacent bands overlapped from 0–66%. One band fissioned during the study; however, the resulting bands did not disperse from the original home range. Seven adult males had a mean home‐range size of 0.37 km2, each extensively overlapping the home ranges of several other males. Observations of 10 adult males whose natal bands were known indicate that when males disperse they do not simultaneously leave the band's home range. Rather, their home ranges remain within or broadly overlapping those of their natal bands. This dispersal pattern is unusual within the order Carnivora.
gompper-biblio
GONZÁLEZ-ACUÑA, D., RIQUELME SALAZAR, P., CRUZATT MOLINA J. et al. (2006)
Diet of the Chilean Tinamou (Nothoprocta perdicaria) in central-south Chile.
ORNITOLOGIA NEOTROPICAL 17: 467–472.
Kurzmitteilung:
... We analysed the contents of crops and stomachs obtained from 79 birds captured in different agricultural areas, years, and seasons in the Ñuble Province, south central Chile. ... Diet consisted mainly of wild plant seeds. The consumption of animal material was scarce and consisted of one insect and crustacean species. During the summer, the seeds of the Poaceae family were most common ... The Chilean Tinamou in Ñuble appears to be essentially a granivorous species with invertebrates being consumed in a variable proportion depending of the season.
gonzalez-biblio
PEACOCK, D. S., VAN RENSBURG, B. & ROBERTSON, M. P. (2007)
The distribution and spread of the invasive alien common myna, Acridotheres tristis L. (Aves: Sturnidae), in southern Africa.
South African Journal of Science 103(11-12):465-473.
Abstract:
The common myna is an Asian starling that has become established in many parts of the world outside of its native range due to accidental or deliberate introductions by humans. The South African population of this species originated from captive birds that escaped in Durban in 1902. A century later, the common myna has become abundant throughout much of South Africa and is considered to pose a serious threat to indigenous biodiversity. Preliminary observations suggest that the common myna's distribution is closely tied to that of humans, but empirical evidence for this hypothesis is lacking. We have investigated the relationships between common myna distribution, human population size and land-transformation values at a quarter-degree resolution in South Africa. Common mynas were found more frequently than expected by chance in areas with greater human population numbers and land-transformation values. We also investigated the spatial relationship between the bird's range and the locations of South Africa's protected areas at the quarter-degree scale. These results indicate that, although there is some overlap, the common myna distribution is not closely tied to the spatial arrangement of protected areas. We discuss the original introduction, establishment and rate of spread of the common myna in South Africa and neighbouring countries and contrast the current distribution with that presented in The Atlas of Southern African Birds. We also discuss the factors that affect the common myna's success and the consequences that invasion by this species is likely to have, specifically in protected areas.
peacock-biblio