243 research outputs found
An experimental investigation of the effects of supplementary food and ground cover on small mammal population dynamics and community structure in a Swaziland grassland.
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1997.The primary aim of this study was to investigate the role of food supply and ground cover on the
community structure, population dynamics and demography of terrestrial small mammals in a
subtropical grassland. This aim was achieved through a series of food supplementation and cover
manipulation experiments conducted at eKundizeni Farm near Matsapha, Swaziland, over a 28
month period.
The effects of five different diets on the rodent Mastomys natalensis were investigated in the
laboratory, and the results showed that rolled oats and rabbit pellets were suitable for growth and
reproduction in this species.
The effects of supplementary food were investigated on two supplemented grids and one
control over a twelve month period. Small mammal biomass increased significantly on the
supplemented grids in relation to the control. This increase in biomass was the result of a twofold
increase in the numbers of M natalensis. Food supplementation further affected M. natalensis by:
extending the breeding season of females; increasing body weight; increasing survival; and
decreasing home range area. Food supplementation had a weak positive effect on the density of
another rodent Lemniscomys rosalia, but did not affect any other demographic feature of this
species. Food supplementation did not have a demographic effect on any other species of small
mammal captured.
The effects of vegetative cover were investigated, over a twelve month period, on two control
grids and four manipulated grids on which the vegetative cover was mechanically reduced.
Supplementary food was added to two of the latter four manipulated grids. The biomass of small mammals, including M. natalensis, was lower on grids with reduced vegetative cover than on the
controls. However, food supplementation resulted in a significant increase in the biomass of M.
natalensis on one of the manipulated grids. Hence, M. natalensis was induced to shift to a habitat
with reduced cover by the provision of supplementary food.
Additional information on the population dynamics, age structure, reproduction and diet of M
natalensis, L. rosalia, Mus minutoides and Steatomys pratensis is also presented
Two new bat species for Swaziland and a revised list for the country
Bat distributions are still comparatively poorly
known in Africa and updated national species lists do not
exist for many countries. We present a revised checklist of
the bats of Swaziland, which includes seven species not
previously listed. Of these, two species are recent additions
(Mops midas and Myotis bocagii) and these records
marginally extend their known distributional range. A
total of 26 species of bats are now known from the country,
but additional surveys are predicted to add more taxa
to the list. These new records predominantly come from
human-modified landscapes, underscoring the importance
of further surveys in such transformed habitats.The National Science
Foundation Graduate Research Fellowship under Grant
No. DGE-1315138 and a Student Research Grant from Bat
Conservation International.http://www.degruyter.com/view/j/mamm2017-05-23am2016Zoology and Entomolog
Species richness patterns and functional traits of the bat fauna of arid southern Africa
The bat fauna of arid regions is still poorly studied mostly due to a lack of interest in areas with low species richness and a low number of threatened species. In this study, we reviewed the status of bat diversity in the arid parts of southern Africa, with the aim of setting up a baseline for future work. In particular, we described species richness patterns across four arid zones within the region (Namib Desert, Kalahari, Nama Karoo and Succulent Karoo), exploring abiotic gradients and local landscape structure. Additionally, we examined bat functional groups in this region and compared them with those of three other arid regions of the world to identify potential similarities and differences. The southern African arid region hosted 17 bat species, representing eight families, of which three are endemic to the region (Rhinolophus denti, Laephotis namibensis and Cistugo seabrae) and one is vagrant (the fruit bat Eidolon helvum). Species richness varied spatially within this arid region, being highest in the drier but topographically heterogeneous Namib Desert, probably as a result of roost availability. With regards to functional groups, the southern African arid region had few bat species adapted to foraging in open spaces, particularly when compared with the neighbouring savannahs. Drawing from this study, we suggest that: a) despite species richness decreasing with increasing aridity at the sub-continental scale, at a more local scale landscape features (e.g. habitat structure) might be more relevant than aridity in determining bat species richness; and b) an unknown factor, possibly patterns of temperature limiting the availability of insects flying high above the ground, restricted the diversity of the open air foragers throughout the region. We highlight additional areas of research worth investigation.Peer reviewe
White-backed vulture Gyps africanus parental care and chick growth rates assessed by camera traps and morphometric measurement
Rufford Foundation and the Peregrine Fund.http://www.tandfonline.com/loi/tost202018-05-19hj2017Mammal Research InstituteZoology and Entomolog
Survival and population dynamics of the Marabou Stork in an isolated population, Swaziland
Investigating the ecology of long lived birds is particularly challenging owing to the time scales involved. Here an analysis is presented of a long term study of the survival and population dynamics of the marabou stork (Leptoptilos crumeniferus), a wide ranging scavenging bird from Sub-Saharan Africa. Using resightings data of tagged nestlings and free flying birds we show that the stork population can be divided into three general life stages with unique survival probabilities and fecundities. Fecundity of the storks is inversely related to rainfall during their breeding season. Corroborative evidence for a metapopulation structure is discussed highlighting the impact of the Swaziland birds on the ecology of the species in the broader region. The importance of tag loss or illegibility over time is highlighted. Clearly, any attempt at conserving a species will require a detailed understanding of its population structure, of the sort examined here
Uplisting a threatened small mammal : the Nimba otter-shrew of West Africa
No abstract available.http://journals.cambridge.org/action/displayJournal?jid=ORXhj2019Mammal Research InstituteZoology and Entomolog
Domestic cats and dogs create a landscape of fear for pest rodents around rural homesteads
Using domestic predators such as cats to control rodent pest problems around farms and homesteads is common across the world. However, practical scientific evidence on the impact of such biological control in agricultural settings is often lacking. We tested whether the presence of domestic cats and/or dogs in rural homesteads would affect the foraging behaviour of pest rodents. We estimated giving up densities (GUDs) from established feeding patches and estimated relative rodent activity using tracking tiles at 40 homesteads across four agricultural communities. We found that the presence of cats and dogs at the same homestead significantly reduced activity and increased GUDs (i.e. increased perception of foraging cost) of pest rodent species. However, if only cats or dogs alone were present at the homestead there was no observed difference in rodent foraging activity in comparison to homesteads with no cats or dogs. Our results suggest that pest rodent activity can be discouraged through the presence of domestic predators. When different types of predator are present together they likely create a heightened landscape of fear for foraging rodents
Temporal and sex-specific variation in growth rates of Marabou Stork Leptoptilos crumeniferus chicks
Temporal and sex-specific variation in growth rates of Marabou Stork Leptoptilos crumeniferus chicks
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