38 research outputs found
Where to with reserve selection and conservation planning in South Africa?
A critical evaluation of the strengths and weaknesses associated with the âminimal setâ approach to designing an optimal reserve network tor vertebrate species is offered. Strengths are the rational and efficient manner in which full species representation is achieved, and the planning benefits that can be gained through its flexibility. Weaknesses include the inappropriateness of the âminimal setâ as a framework for a reserve network, and the frequent confusion between top-down relational species criteria and bottom-up site attributes. It is suggested that the distinct âtop-downâ relational and âbottom-upâ representation approaches may act synergistically to form the basis of a National Biodiversity Conservation Strategy. These complementary approaches may require different forms of protection and monitoring, but could also be amalgamated to develop a conservation strategy for non-protected areas. Sufficient attention should also be paid to encouraging the free flow of information and to incorporating the principles of taxonomic and environmental uncertainty into future conservation policies
Towards conserving regional mammalian species diversity: a case study and data critique
Species richness maps were derived for the Transvaal region from two different databases, namely a primary point database based on actual survey records and a generalized distribution map database. It is shown that sixteenth degree grid square (= QDS in Lombard 1995) species richness maps based on these two data sets for the region are highly disparate, which may be attributed to overestimation of species distributions by distribution maps and uneven sampling reflected in the primary point database. The limitations and problems associated with the two databases are discussed. Of the 10% most species-rich grid squares based on distribution maps and primary point data, 33,3% and 12% respectively are fully encompassed by existing conservation areas and are well represented in the sixteenth degree grid square networks selected by two iterative reserve selection algorithms
Plasma androgen concentrations in initial samples from spotted hyaenas immobilized with Zoletil (CI-744) reflect hormonal status estimated by GnRH challenge and immobilization stress response
The use of single samples to assess the androgen status of animals can be problematic owing to extensive short-term fluctuations in the concentrations of these hormones. Thus, this study evaluated a number of estimates for both testosterone and androstenedione status in the spotted hyaena (Crocuta crocuta),namely, initial samples, the immobilization stress response and the response to exogenous GnRH administration, for their mutual consistency. This study found that in animals immobilized with Zoletil and maintained on halothane, all three estimates show a good consistency. Moreover, the large variance in androgen status reported here within the sexes explains earlier contradictory results, and implies that the debate concerning the sex-specific differences in plasma androgens is confounded by other variables such as the reproductive and social status of the individuals included in the analysis
Scale and conservation planning in the real world
Conservation planning is carried out on a variety of geopolitical and biogeographical scales. Whereas considerable consensus is emerging about the most appropriate procedures for identifying conservation areas, the spatial implications of conducting conservation planning at divergent scales have received little attention. Here we explore the consequences of planning at different geopolitical scales, using a database of the mammalian fauna from the Northern Provinces of South Africa. The conservation network resulting from treating the region as one unit is compared with networks generated separately for the provinces nested in that region. These outcomes are evaluated in terms of (i) their land use efficiencies, (ii) their spatial overlap, and (iii) the impact of algorithm attributes. Although land use efficiencies are greater on broader scales, on average the spatial congruence between the broad-scale regional network and fine-scale provincial networks was less than 14%. Algorithms using different selection rules fail to improve this disturbing outcome. Consequently, scale has an overwhelming influence on areas identified as conservation networks in geopolitical units. This should be recognized in conservation planning
A comparative analysis of components incorporated in conservation priority assessments: a case study based on South African species of terrestrial mammals.
Assessing the risk of extinction to species forms an essential part of regional conservation initiatives that facilitate the allocation of limited resources for conservation. The present study conducted conservation priority assessments for 221 South African terrestrial mammal species using existing data sources. These data sources included regional IUCN Red List assessments, regional geographic distributions, relative endemism, taxonomic distinctiveness, relative body mass and human density. These components were in turn subjected to two quantitative conservation priority assessment techniques in an attempt to determine regional conservation priorities for South African terrestrial mammals. The top 22 mammal species (i.e. the top 10% of assessed species) identified by both regional conservation priority assessment techniques to be of conservation priority, consistently identified 13 South African terrestrial mammal species to be of high conservation priority. Seven of the 13 species were from the order Afrosoticida, two species from the order Eulipotyphla, with one species each from the orders Chiroptera, Lagomorpha, Pholidota, and Rodentia. More importantly, 12 of the 13 mammal species were also listed as threatened in the 2004 Red Data Book of South African Mammals. These results suggest that the two conservation priority assessment techniques used in the present study may represent a practical and quantitative method for determining regional conservation priorities, and include measures that represent vulnerability, conservation value, and threat.DST-NRF Centre of Excellence for Invasion Biolog
A comparative analysis of components incorporated in conservation priority assessments: a case study based on South African species of terrestrial mammals.
Assessing the risk of extinction to species forms an essential part of regional conservation initiatives that facilitate the allocation of limited resources for conservation. The present study conducted conservation priority assessments for 221 South African terrestrial mammal species using existing data sources. These data sources included regional IUCN Red List assessments, regional geographic distributions, relative endemism, taxonomic distinctiveness, relative body mass and human density. These components were in turn subjected to two quantitative conservation priority assessment techniques in an attempt to determine regional conservation priorities for South African terrestrial mammals. The top 22 mammal species (i.e. the top 10% of assessed species) identified by both regional conservation priority assessment techniques to be of conservation priority, consistently identified 13 South African terrestrial mammal species to be of high conservation priority. Seven of the 13 species were from the order Afrosoticida, two species from the order Eulipotyphla, with one species each from the orders Chiroptera, Lagomorpha, Pholidota, and Rodentia. More importantly, 12 of the 13 mammal species were also listed as threatened in the 2004 Red Data Book of South African Mammals. These results suggest that the two conservation priority assessment techniques used in the present study may represent a practical and quantitative method for determining regional conservation priorities, and include measures that represent vulnerability, conservation value, and threat.DST-NRF Centre of Excellence for Invasion Biolog
International review of the Globio model version 3
In April 2005, a review committee gathered to assess the scientifically validity and policyrelevance of the GLOBIO3 model as part of the International Biodiversity project. Four members of the committee are scientists with a great experience in biological research assessing the GLOBIO3 model from a scientific perspective, while two members are working at UNEP assessing the model from a userÂżs perspective. Their judgment and recommendations are presented in this report. The conclusions are important in order to keep the modelling work scientifically sound as well as focussed on the major political key questions in the international arena. The review committee concluded the GLOBIO3 project is well suited to play in important role in providing information on understanding ongoing trends and depicting future trends in regional and global assessments. However, the scientific imbedding and acceptance has to improve, while, simultaneously, the dialogue with policy makers needs to be strengthened. This report serves primarily as guidance for the International Biodiversity project but can also serve as an independent review on the validity of the model for any potential end user
Aspects of the digestion in the Cape porcupine
The digestive capabilities of the Cape porcupine (Hystrix africaeaustralis) were studied using captive and field animals. The stomach contents comprised 6,47% of the body mass and had a low pH (2,0).The Cape porcupine also has a long small intestine (670 em). The large stomach and small intestine form a very efficient protein digesting (83,8%) apparatus. The caecum is relatively small, constituting 2,7% of the body mass. On a high fibre diet food intake declined and retention time of digesta in the tract increased. Fibre is probably only included in the diet at times of food shortage.Die verteringsvermoe van die Kaapse krimpvarkie (Hystrix africaeaustralis) is ondersoek deur gebruik te maak van diere in gevangenisskap en in die veld. Die inhoud van die maag het 6,47% van die liggaamsmassa uitgemaak en het 'n lae pH (2,0) gehad. Die Kaapse krimpvarkie het ook 'n lang dunderm (670 em). Die grootmaag en dunderm vorm 'n baie effektiewe prote" ienverteringsapparaat (83,8%). Die sakderm is relatief klein en maak 2,7% van die liggaamsmassa uit. Op 'n hoe veseldieet het inname afgeneem en die retensietyd van verteringsmateriaal in die kanaal het toegeneem. Vesel word waarskynlik net by die dieet ingesluit ten tye van voedselskaarste.Keywords: Porcupine digestion, morphometries, digestibility, colon fermenter, transit tim
Adaptations in three species of large mammals (Antidorcas marsupialis, Hystrix africaeaustralis, Hyaena brunnea) to arid environments
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An assessment of biodiversity surrogacy options in the Limpopo Province of South Africa
Because of the inadequacy of existing biodiversity distribution data, surrogate measures for regional biodiversity have long been used in conservation area selection. These measures include species and environmental data. However, the assumed relationship between surrogate measures and regional biodiversity has seldom been demonstrated. This study uses species and environmental surrogates (vegetation and landtypes) in selecting areas for conservation in the Limpopo Province of South Africa. The success of these measures in capturing known regional biodiversity is evaluated, as well as their success at identifying areas containing threatened, rare and endemic non-target biodiversity features. The effects of size, scale and quality of databases are also evaluated. There is a trade-off between representing non-target biodiversity features (especially rare, threatened and endemic features) and land-use efficiency. The trade-off between efficiency and representation suggests that many important conservation areas identified will rely on off-reserve management rather than formal protection. Furthermore, the results suggest that the IUCN-recommended national conservation targets of 10 % are inadequate.Key words: conservation, environmental surrogate, landtypes