Showing papers in "South African Journal of Wildlife Research - 24-month delayed open access in 1996"

Ecological guidelines for waterpoints in extensive protected areas

Abstract: Augmenting natural water supplies by providing artificial waterpoints is an intervention commonly adopted by managers of national parks and other large protected areas. Contrasting policies are currently being followed in three of the premier national parks in southern Africa. Some empirical guidelines for waterpoint provision are suggested by case histories of these and other wildlife reserves. A geometric model, based on the rotation of water-dependent herbivores between wet season and dry season ranges, is outlined to indicate the appropriate spacing between perennial waterpoints. The aim is to apportion vegetation impacts evenly between these ranges, and allow plants a period of recovery from severe grazing pressure. The model suggests that a much wider spacing between perennial water sources is advisable than is currently operative in most conservation areas. Seasonal waterpoints reduce the period of concentration near perennial water, but prolong use of vegetation in the wet season range. Excessive waterpoints (1) favour water-dependent ungulates and elephants at the expense of rarer ungulates, (2) increase predator impacts on prey populations, (3) widen vegetation degradation, (4) worsen animal mortality during droughts, (5) decrease ecosystem stability, and (6) lead to a loss of biodiversity.

Economic and financial incentives for wildlife use on private land in Namibia and the implications for policy

Abstract: Aggregate estimates for wildlife populations and species diversity on private land in Namibia were made for 1972 and 1992, using questionnaire surveys. Animal numbers and biomass appear to have increased by some 80%, or 3% per annum, over the period. The number of game species recorded increased by 44%. Cost-benefit analysis models were developed and used to analyse economic and financial efficiency of land use involving wildlife on private land. Financial profitability was generally low in the case of both livestock-game production for consumptive use and wildlife production for non-consumptive use. However these activities appear to be economically efficient, and result in a positive contribution to national income. The results suggest that there are financial incentives for private landholders to group together and form large scale conservancies. The latter benefit from economies of scale which make them more financially profitable and robust, and also more economically efficient, than ranches. Wildlife production for non-consumptive wildlife viewing yielded greater economic net value added per unit of land than livestock-wildlife production for consumptive use, particularly at the larger conservancy scale of operation. Aggregate estimates, in 1994 prices, of the annual net value added to national income from wildlife use on private land are N$ 30.6 million in 1972 and N$ 56 million in 1992. The economic value of wildlife use as a proportion of the total value of private land rangeland use has risen from 5% to 11% over the 20-year period. Current policy to promote both wildlife use and the development of wildlife conservancies on private land appears to be economically sound.

Some reflections on conservation, sustainable development and equitable sharing of benefits from wildlife in Africa : the case of Kenya and Zimbabwe

Abstract: African wildlife represents a unique type of terrestrial biodiversity whose current and future importance should not be underestimated. However, the future of wildlife in Africa is threatened as the largely protectionist approaches to conservation of this resource, which have been used for many years, are no longer viable. Local communities have had little or no role to play in the conservation of wildlife although they suffer from the inconveniences of sharing the same ecosystem with wildlife and receive a negligible share of the benefits that accrue from wildlife. Consequently, there is growing conflict between local communities and wildlife, whereby wildlife is not considered a priority form of land use since it does not offer immediate benefits to the local communities. In this paper we examine the issue of equitable sharing of benefits (and costs) of wildlife conservation in Africa, and the problems associated with local participation in the management of this resource with specific reference to Kenya and Zimbabwe. We further explore the issue of wildlife ownership and how this affects the local people's willingness to provide land for wildlife and hence its sustainable conservation. It is concluded that involvement and support of local communities in wildlife conservation is a prerequisite to effective and long-term conservation of wildlife and wildlands as part of the terrestrial biodiversity conservation. We propose that it is possible to reconcile the conservation of wild resources with economic development and human welfare so as to ensure that African countries with these resources have an incentive to ensure their long-term management and survival. New strategies for sustainable management of wildlife must address the issues of ownership as well as effective institutions and mechanisms of ensuring equitable sharing of benefits that accrue from wildlife.

Habitat partitioning by ungulates on a game ranch in the Mopani veld

Abstract: Large herbivores display varying degrees of habitat selectivity and thus exhibit a heterogeneous distribution. This study investigated the spatial and temporal distribution of Burchells zebra Equus burchelli, blue wildebeest Connochaetes taurinus, eland Taurotragus oryx, gemsbok Oryx gazella, giraffe Giraffa camelopardalis, impala Aepyceros melampus, kudu Tragelaphus strepsiceros, and warthog Phacochoerus aethiopicus, on the Messina Experimental Farm. The sighting frequency of the ungulates, expressed as distance covered by vehicle, divided by the number of individuals of a species recorded, is presented for each of the plant communities in the study area. The road counts revealed that the sighting frequency of ungulate species in the different communities showed considerable variability. Correspondence analysis detected seasonal fluctuations in preference. In the warm, dry season the ungulates were widely separated in their use of the plant communities. Thirteen habitat variables that contributed to this ecological separation were identified. Preferences for plant communities, their seasonal variation and selection for specific environmental parameters, contributed to the ecological separation of ungulates on the Messina Experimental Farm.

Habitat and diet of bush buck Tragelaphus scriptus in the Woody Cape Nature Reserve : observations from faecal analysis

Abstract: Faecal and observational data were used to determine habitat use and diet of bushbuck in the Woody Cape Nature Reserve. Faecal transect data indicated that bush buck exhibit habitat selection : dense habitats were selected above more open habitats. Observational data confirmed this selection. Faecal transect data provided more reliable results than observations, being subject to fewer biases. Diet composition estimated from faecal analysis indicated that bushbuck were predominantly browsers, taking an average of 9.6% monocotyledonous plants per month. Twenty-three dicotyledons but only three monocotyledons were identified in the faeces. Preference indices showed that four plant species were utilized to a greater degree than their occurrence in the veld would suggest. Diet quality estimated from faecal samples indicated that bushbuck in the Woody Cape Nature Reserve were not suffering from nutritional limitations (as measured by % fibre, % ash and % crude protein), as their protein intake adequately met their requirements, despite the prevailing drought during the study period. We conclude that analysis of faecal material is an efficient and cost-effective approach to provide appropriate ecological information.

Preliminary results on the role of KwaZulu-Natal harbours as nursery grounds for juveniles of selected marine organisms which utilize estuaries

Abstract: Estuaries and lagoons along the South African coast provide the only sheltered conditions on an otherwise high energy coast. The juveniles of numerous marine species, some of which are dependent on estuaries, utilize these as nursery grounds where they remain until attaining maturity. Currently most KwaZulu-Natal estuaries are being impacted upon by changing land-use patterns in their catchments and developments along their shorelines. The nursery function of many has substantially diminished over the past 30 years. Two major deep water harbours, Durban and Richards Bay exist on estuarine embayments in KwaZulu-Natal. Preliminary investigations showed that they are playing an important role as nursery areas for juveniles of marine fish and penaeid prawns normally found in estuaries. This role could be enhanced by the implementation of an environmental management policy for each harbour in conjunction with designating sites, not due for development, as natural areas. Manipulation of the latter areas could further increase the importance of these harbours for juvenile marine organisms which normally utilize estuaries along the KwaZulu-Natal coast.

Land uses on the Botswana / Zimbabwe border and their effects on buffalo

Abstract: This ongoing study relates human land use management to movements by large mammals, particularly the African buffalo (Syncerus caffer). Movements are related to two landscape-scale variables : the risk of predation and the availability of water. As a contribution to the emerging field of landscape ecology, study objectives are to elucidate (1) how a large herbivore responds to certain management schemes with changes in their distribution across the landscape, and (2) the spatial requirements of buffalo for water, food, and predator levels, predators including humans as well as lions (Panthera leo). In the border region of western Zimbabwe and eastern Botswana, five very different land use types are available to mobile mammals, in a large unfenced region managed consistently from 1975-1995 for consumptive and non-consumptive utilization of natural resources. Buffalo breeding herds are spoored to show their movements and utilization of resources at three scales, through a six month dry season. Frequency of predation attempts and buffalo herd distributions are obtained from spoor, interviews with residents, driven transects, and mortality records from both countries' Departments of Wildlife and National Parks. Water availability is mapped monthly from the air. Herd selection of areas with different water and risk levels indicate their preferred land management regimes. This paper represents the first year's results at the large scale; the distributions of buffalo and permanent water correlating closely. The land use types differ in water distribution and predation pressure. Although lion predation occurred at similar high rates throughout the region, hunting pressure varied from none to several hunters searching daily for buffalo through the dry season. The behaviour of these generalist herbivores, capable of moving large distances, supports hypotheses that animals move further between food and water as the dry season progresses, and as risk levels differ. Buffalo move and forage differently in Safari Areas (managed for low-impact safari hunting, high-density provisioned water, and high habitat diversity) than in National Parks (some of which pump water through the dry season). The maximum distance from water a breeding herd was found in 1995 was 8.7 km. This, and herds' greater use of safari areas over similarly watered National Parks lands indicates that the safari areas may provide greater benefits than costs to mobile mammals such as buffalo.

Acute toxicity tests of copper on juvenile Mozambique tilapia, Oreochromis mossambicus (Cichlidae), at different temperatures

Abstract: In the Olifants River, copper is one of several metals which pose a threat to the conservation status of the river. The LC50 values attained during this study, can be used as an indication of the levels at which copper becomes lethal to O. mossambicus and must only be seen as the limits within which the concentration of copper can be regarded as lethal for this species in the Olifants River. Acute toxicity tests were performed to determine the lethal copper concentrations for juvenile Oreochromis mossambicus at representative mean summer (29°C) and winter temperatures (19°C) of the Olifants River, Kruger National Park, Northern Province, South Africa. Fish were exposed to various copper concentrations (0.0, 1.0, 1.7, 1.8,2.0,2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 3.0, 3.5, 4.0 mg / l) for 96 h in experimental flow-through systems at pH levels which ranged between 7.4 and 8.1, and mortalities were monitored. Dosage-survival curves of percentage survival versus actual copper concentrations were plotted after 24, 48, 72 and 96 h, and thereafter the LC50 or median lethal concentration (the concentration of the test material that will kill or immobilize 50% of the test organisms over a predetermined length of time, usually 24 to 96 h) values were calculated for both summer and winter temperatures. Time survival curves of percentage survival versus time were also plotted, after which the LT50 or median survival time (the time required for half the fish to die at a specific toxicant concentration) values were calculated for the two temperatures. Toxicity curves were constructed using both the LC50 and LT50 values to determine the incipient LC50 values (ILC50 - the lethal concentration for 50% of the test organism in a long-term exposure or lethal threshold concentration). The LC50 values (lethal copper concentration) of 2.61 mg / l and 2.78 mg / l as well as the ILC50 values (lethal threshold concentration) of 2.95 mg / l and 3.32 mg / l for copper at 29 ± 1°C and 19 ± 1°C respectively, are considerably higher than the copper concentrations occurring in the water of the Olifants River, during summer (0.055 ± 0.016 mg / l) and winter (0.085 ± 0.032 mg / l). Thus the fish in the Olifants River are not exposed to acute lethal copper concentrations.

Population growth of roan antelope under different management systems

Abstract: Roan antelope Hippotragus equinus equinus is an endangered species in southern Africa. Appropriate management strategies, under intensive systems, may be to the advantage of roan populations. The exponential rate of increase of roan populations under various degrees of intensive management was investigated. A one-way analysis of variance was used to test the null hypothesis that there is no difference in the rate of increase between roan populations. The roan population on the Nylsvlei Nature Reserve had a negative rate of increase. The high exponential rate of increase (0.2574) of the small Rooipoort population differed significantly (p < 0.05) from all other populations. This population grazed on planted pastures and was fed during the dry season with at least 0.5 kg of supplementary food per day (mixture of lucerne, antelope cubes and lick). It also had the highest sex ratio. Under intensive management. animals may be stocked at a density of up to 20 animals / km2. The Spearman's rank correlation coefficient showed that the rate of increase was correlated with the amount of supplementary feeding. For the populations investigated no correlation was found with % females, % calving rate, population size and density.

Helmeted guineafowl Numida meleagris in KwaZulu-Natal : a case for non-sustainability

Abstract: Helmeted guineafowl Numida meleagris populations in KwaZulu-Natal which once provided some of the best gamebird hunting in Africa have declined significantly over the past 15 years. This study investigated, by means of a questionnaire survey, the apparent collapse of guineafowl populations in the KwaZulu-Natal Midlands and Drakensberg regions, and the potential agricultural causes thereof. The number of pesticides used, their toxicity levels, and the proportion of land under cultivation can be used to discriminate significantly between extinct and declining versus stable and increasing guineafowl populations, being higher in the former populations. These results suggest that efficient, intensive farming practices have not only compressed the period in the farming year over which food is available to the guineafowl, but also reduced the suitability of farmlands as wildlife habitat. Remedies are suggested to resuscitate declining populations and optimize their long-term preservation for potential sustainable utilization. Recommended management actions include the judicious use of pesticides and the creation of suitable habitat at the landscape scale.

Helicopter-based line-transect estimates of some Southern African game populations

Abstract: The results of helicopter-based counts of some South African animal species in the Northern Cape Province are presented. A distance-based estimator is used to provide a correction for those individuals present but not seen. Two different types of helicopter with a different number of observers are compared. The results indicate significant undercounting even for the largest species. Increasing the number of observers provided a less biased and more precise estimate. Visibility profiles for some species are presented. For most species the proportion of the population seen beyond 200 m from the helicopter is small. An estimator for the variance of total counts is derived, based on the visibility profiles and is evaluated for a selection of species. The results indicate that attempts to count animals up to 400 m from the aircraft provide an estimate which is both more biased and less precise than estimates obtained by counting animals in the first 200 m only. We also suggest that the proportion of animals seen with small helicopters with fewer observers, as generally used in game counting on wildlife ranches, is lower than in this study. Die resultate van 'n bevolkingsopname per helikopter van sommige Suid-Afrikaanse diersoorte in die Noord-Kaap provinsie word aangebied. 'n Afstandsgegronde skatter is gebruik om 'n korreksie te maak vir individue wat teenwordig was maar nie waargeneem is nie. Twee verskillende tipes helikpoter met verskillende getalle waarnemers in elk is vergelyk. Aansienlike ondertellings vir selfs groot diere is gemaak. 'n Toename in die getal waarnemers het 'n minder sydige en meer presiese beraming tot gevolg gehad. Sigbaarheidsprofiele word vir sekere spesies aangebied. Die verhouding van diere wat verder as 200 m van die helikopters waargeneem word is klein vir die meeste spesies. 'n Skatter vir die variansie van totale tellings, gegrond op die sighaarheidsprofiele, is afgelei, en word geevalueer vir 'n seleksie van spesies. Die resultate dui aan dat pogings om diere te tel tot sover as 400 m weg van die helikopter minder presies en meer sydig is as tellings waar diere net tot 200 m weg getel word. Ons stel ook voor dat die proporsie van diere wet waargeneem word met kleiner helikopters met minder waarnemers, soos normaalweg op wildplase gebruik word, laer sal wees as in hierdie ondersoek.

Official statistics on the income generated by the hunting industry in South Africa

Abstract: Official statistics on the income generated in the hunting industry in South Africa are described, placed in an economic perspective and their shortcomings outlined. The statistics utilized are drawn from the 1988 agricultural census in which information on incomes earned from various types of farming is reported. It is concluded that these statistics understate the income generated by the industry and that more accurate estimates are desirable.

The diet and conservation of monogamous and polyandrous pale chanting goshawks in the Little Karoo, South Africa

Abstract: The diet of pale chanting goshawks (PCGs) Melierax canorus that live in groups, i.e. a monogamous pair or polyandrous trio with or without non-breeding offspring, was investigated near Calitzdorp, Western Cape Province, South Africa. Based on biomass, PCGs prey mostly on rodents, but also small birds, hatchling tortoises, small snakes, lizards, sunspiders, harvester termites, grasshoppers, beetles and carrion. Published observations of PCG prey are not in dose agreement with these results, since many large birds, but few invertebrates were reported. For the three dominant prey species combined, Otomys unisulcatus, Parotomys brantsii and Rhabdomys pumilio, the proportion of the biomass was the highest for polyandrous (93%) and monogamous groups (91%) from Karroid Broken Veld. Since cooperative polyandry was only reported from this vegetation type, the selection of these rodents appears to be an important component of habitat quality for these birds. Stocking rates of ostriches Struthio camelus, for which the study area is utilized almost exclusively, may be critical for the conservation of this rare mating system since changes in habitat structure owing to the ostriches' avoidance of shrubs and succulents may benefit the otomyinids directly. Alternatively, high stocking rates that open up the habitat may impact negatively on otomyinid abundance.

Effects of harness-attached satellite transmitters on captive whitefaced ducks Dendrocygna viduata : : short communication

Abstract: The effects of teflon harness-attached 30-g satellite transmitters on the activity patterns, and body mass of captive whitefaced ducks Dendrocygna viduata were investigated. The diurnal activities of transmitter affixed birds (TAB)(140 h) and control birds (CB)(140 h) were monitored in captivity over a period of 14 weeks. There were no within-week differences in the behavioural patterns between TAB and CB (p > 0.05). However, TAB spent a larger portion of the day preening (10.6%) than CB (7.1%), (p 0.05). Increases in body mass were higher for TAB (56.92 g) than CB (12.80 g) (p = 0.006). Teflon harness-attached 30-g satellite PTTs have a minor effect on activity patterns and do not adversely influence the body mass, skin or feathers of captive whitefaced ducks.

Small mammals in afforestable montane grasslands of the northern Eastern Cape Province, South Africa

Abstract: The small mammals at five sites on each of six land types in the afforestable grasslands of the northern Eastern Cape Province were sampled. Sampling grids consisting of 100 equally spaced trapping points were used. Mean species richness and relative abundance per hectare did not differ significantly over the land types. Significant associations between site type and species relative abundances were : valleys and north slopes with Rhabdomys pumilio; south slopes with Myosorex varius and Otomys irroratus; east slopes with M. itarius; and crests with Mus minutoides and Mystromys albicaudatus. The threatened, rare species M. albicaudatus was associated with crests and ridges.

Habitat selection by the gerbils Gerbillurus paeba and G. tytonis in the Namib Desert dunes

Abstract: Habitat selection, in relation to plant species diversity, plant biomass, plant cover and substrate compaction was investigated in the pygmy hairy-footed gerbil Gerbillurus paeba and the dune hairy-footed gerbil G. tytonis at three study areas situated across the Namib Desert dunefields. Plant species diversity and substrate compaction were the major habitat variables implicated in ecological segregation between the congeners. G. tytonis preferred habitats with high plant species diversity, avoided compact soils and at the most easterly study site preferred soft shifting sand. G. paeba avoided areas with high plant species diversity and preferred habitats with low plant species diversity. In the absence of G. paeba, G. tytonis selected habitats with a high plant species diversity suggesting that the presence of G. paeba did not influence the habitat selection of G. tytanis. There is no competitive release and G. tytanis does not invade habitats usually occupied by G. paeba.

Wildlife management, land-use and conflicts

Abstract: The paper analyses the conflict between wildlife conservation and its accompanying land use in an East African context. In the model there are two agents. First, there is an agency managing the wildlife and the habitat of the wildlife, which is referred to as parkland. On the other hand, there is the group of agro-pastoralists living in the vicinity of the wildlife habitat, whose land use is referred to as rangelands. The parkland is used for tourism production and hunting, while the rangelands are used for agropastoral production. Both agents will find it beneficial to expand their land-use, so there is a land-use conflict. This is analysed in two steps. First, social optimality is studied; then the utilization of the wildlife and its accompanying land-use when there is no unified resource policy and the park agency follows its self-interest. The effects of the two different management schemes of changing economic conditions, such as the recommendations of the CITES convention and a programme subsidizing agro-pastoral production, are duscussed.

Proceedings VI International Otter Colloquium, Pietermaritzburg 1993 - Habitat No. 11, C. Reuther and D. Rowe-Rowe (Eds.) : book review

Abstract: The conservation of otters has been a topic of significant interest for approximately the past two decades. This is primarily because the Eurasian otter Lutra lutra has become endangered or extinct in many countries. There has, however, been a recent comeback in the distribution of these otters in many areas. The reasons for previous declines and the recent comeback remain speculative, although pollution and destruction of habitat are usually blamed for the declines. It not only the Eurasian otter that has declined, but many of the World's 12 other otter species.

Notes on the effects of sub-lethal doses of lindane and aldicarb on the reproduction of common quail : short communication

Abstract: Lindane and aldicarb were dissolved in the drinking water of captive common quail Cotumix cotumix at doses of 1, 3 and 9 ppm and 1.5, 2.25 and 3 ppm, respectively, for seven days. Eggshell thickness, egg volume, egg mass, incubation time, hatchability and embryo development were recorded prior to, during and after the treatment. Egg production was not affected by exposure to either lindane or aldicarb. Egg mass was reduced significantly and egg volume increased slightly at 3 ppm lindane. There was no significant eggshell thinning as a result of exposure to lindane. Fertility and hatchability were lower at 3 and 9 ppm of lindane. Furthermore, incubation period was slightly reduced and overall fecundity decreased as a result of lindane ingestion. At higher concentrations, egg mass increased significantly post aldicarb treatment. Aldicarb exposure did not significantly change shell thickness. However, fertility was slightly reduced during treatment. For fertile eggs, hatchability was also reduced. The reduced hatchability can be partly attributed to a high rate of embryo mortality. However, hatchability remained high during all phases of the study.

Lack of allozyme heterogeneity at eight loci studied in a roan antelope Hippotragus equinus population from the Percy Fyfe Nature Reserve : short communication

Abstract: Protein gel-electrophoresis was used to assess genetic diversity in an isolated roan antelope Hippotragus equinus population. No allelic polymorphism was detected at loci previously identified as polymorphic in this species and in other species of the subfamily Hippotraginae. The possible contribution of recent management record and historic events to the present lack of heterogeneity are discussed.

Improved training in wildlife utilisation of veterinarians in Uganda

Abstract: Training of veterinarians in animal resource management in Uganda have so far over-depended on traditional professional profiles based on conventional utilisation patterns. Critical analysis of existing resource-flows and innovative design of more appropriate and integrated utilisation models will be required to meet future increased quantitative and qualitative demands from resources and veterinary resource personnel. Ecological epidemiological and socio-economic approaches to integrated and sustainable utilisation must be given priority and have to be supplemented by conventional veterinary intervention. Examples of more appropriate demand-driven intervention approaches are provided. Practical field training supported by experts is crucial to realise utilisation opportunities.

Simulated protein requirements and seasonal breeding in impala Aepyceros melampus

Abstract: The protein requirements of an impala female were modelled for maintenance, pregnancy and lactation. The required dry matter intake to supply this protein demand were compared to modelled dry matter intake for different conception dates. The results support the hypothesis that the period of high nutritional demand, late pregnancy and lactation, is synchronized with the availability of good quality forage. However, this model suggests that breeding may take place between March and July, without affecting the protein balance, providing circumstantial evidence that predation further restricts the breeding season.