André F. Boshoff

Options for the conservation of large and medium-sized mammals in the Cape Floristic Region hotspot, South Africa

We assessed options for conserving the large- and medium-sized mammals indigenous to the Cape Floristic Region, South Africa, using systematic conservation planning, the first such attempt for an entire ecoregion. The potential distributions and abundances of the 41 extant species for the entire region prior to anthropogenic transformation of habitats were estimated. This was particularly useful as it obviated any reliance on records of occurrence for conservation planning. Areas that had not been transformed through agriculture or other developments were considered available for conservation. The fragments of untransformed habitat were identified as being large enough to support communities at least 25 individuals of the smallest herbivore species. Smaller fragments were not considered suitable for mammal conservation. Transformation and fragmentation had significant impacts on potential populations, and this was asymmetrical across species, being higher for lowland than montane species. The existing reserve system was estimated to effectively conserve only half the mammal species, using the criteria applied here. Two conservation goals were compared; first, either conserving only CFR endemics and threatened species; and second, conserving all the mammals (with some exceptions for marginally occurring species). Options for protected area systems were assessed using C-Plan, a decision support system designed for systematic conservation planning. The irreplaceability of the planning units varied only slightly under the two goals, and the more inclusive goal was used to develop a proposed reserve network in which targets for all the species were achieved. The CFR endemics and threatened species effectively function as umbrella species for the remaining mammals. This study demonstrates that the incorporation into systematic conservation plans of conservation targets adequate for the persistence of populations comprising communities across entire ecoregions is feasible

Modelling survival rates in the Cape Griffon Gyps coprotheres, with emphasis on the effects of supplementary feeding

Survival rates are crucial demographic parameters for modelling the population dynamics of the Cape Griffon vulture. Previous survival estimates based on ring recoveries are seriously flawed and have been heavily criticized. To provide better estimates, 97 nestlings were individually colour-ringed in the winterrainfall region of South Africa from 1979 to 1987 and an intensive resighting campaign was mounted for 17.5 years (1980 to mid-1997). Although survival rate is known to vary with age, particularly in the first few years of life, this study indicates that it is also a function of calendar year. Supplementary food was provided for the study population from 1984 onwards and there was a concomitant increase in the survival rate of first-year birds. Eighty generalized linear models were built to estimate survival rate as a function of age, calendar year, cohort and supplementary feeding. First-year survival rate was estimated as 42.3% per annum (95% limits: 29–56%), increasing to 68.9% (54–81%) after the...

The impact of power line-related mortality on the Cape Vulture Gyps coprotheres in a part of its range, with an emphasis on electrocution

The global population of the Cape Vulture Gyps coprotheres , a threatened southern African endemic, is known to be impacted by electrocutions and collisions on power line infrastructure, but to date this impact has not been estimated or quantified. Using data in a national database from the period prior to our study, conducted in the Eastern Cape Province of South Africa, we estimated a mean annual mortality rate from power line-related mortality of around 14 vultures per year. After applying an adjusted rate based on the results of a landowner survey, this estimate increased to around 80 vultures per year (i.e. a 5.7 fold increase). For a number of reasons, the estimated mean annual mortality rate is considered to under-represent the true situation, and must therefore be considered a minimum value. A simple model was constructed and run to investigate the potential impact of the mortality rate from electrocution on the study population. It distinguishes between vulture subpopulations in areas of high and low electrocution threat, and a migratory subpopulation that moves between these two areas. The model, simulated over 50 years and applying a constant theoretical maximum annual growth rate of 2%, indicates positive growth of the population in those areas where the electrocution threat from power lines is low, whereas the population in those areas where this threat is high is predicted to crash to extinction, from electrocution mortality alone, within a 20–35 year period. The regional population is predicted to show positive growth over the 50 year period. However, for a number of reasons that relate to the nature of certain parameters used in the model, the simulations must be considered to be conservative, at best. In addition, other unnatural mortality factors (notably inadvertent poisoning, drowning in high-walled farm reservoirs, harvesting for the traditional medicine trade, local food shortage), which are additive to power line-related mortality have not been taken into account. Management recommendations aimed at obtaining an improved estimate of the mean annual mortality rate from power lines, and at ameliorating the impact of electrocutions on the regional Cape Vulture population, are briefly mentioned. These address the former by documenting ways to improve the quantity and quality of the field data, and the latter by identifying areas where urgnt action needs to be taken to reduce or avoid the electrocution of vultures, by mitigating extant ‘unsafe’ power line infrastructure, and by ensuring that that only ‘safe’ infrastructure is used for new power lines.

Profiles, views and observations of visitors to the Addo Elephant National Park, Eastern Cape, South Africa

The views of visitors to national parks provide an important source of information to guide park planners and managers. A visitor questionnaire study was conducted in 2004 and 2005 in the Addo Elephant National Park, South Africa. A profile of the respondents, as well as records of their views on a number of park-related conservation and management issues, and of their observations of large and charismatic species (the ‘Big Five’) was compiled. The study clearly showed that national parks are important destinations for an African wildlife experience, along with other natural attractions that they have to offer. It also highlighted the scope for further visitor education, specifically aimed at improving the quality of their visits to the park. The relationship between elephant (Loxodonta africana) density and level of viewing success by visitors requires further investigation. Since the reintroduction of large predators, especially lion (Panthera leo), in the early 2000s, the daytime sighting rate of buffalo (Syncerus caffer) by visitors has increased markedly. Ongoing surveys, to monitor and expand on some of the aspects addressed in this study, are considered necessary in order to assist park staff to achieve conservation and management goals.

Preliminary observations on the diet of leopards (Panthera pardus) from a conservation area and adjacent rangelands in the Baviaanskloof region, South Africa

ABSTRACT Pastoralists on rangelands adjacent to the Baviaanskloof Provincial Nature Reserve, Eastern Cape, report stock losses through predation by leopards (Panthera pardus). This leads, in certain cases, to persecution of the leopards. This study attempted to quantify livestock depredation by leopards by comparing leopard diet within and outside the reserve. Leopard scats from both areas were analysed for prey items. A total of 18 prey taxa was identified, including small to medium-sized ungulates, rodents, birds and a felid. The mountain reedbuck was the most frequently utilized prey, followed by vlei rat, bushbuck, rock hyrax and grysbok. Baboons, although abundant throughout the study area, were not utilized by these leopards. There was a significant difference in the frequency of prey items between the reserve and the rangeland samples in terms of the relative contribution of the prey taxa. Medium-sized and small ungulates were heavily utilized in the reserve, whilst the diet in rangelands was composed largely of small mammals (including small ungulates). Only two scats contained the remains of domestic animals, indicating that <5% of the diet comprised this prey category, and suggesting that leopards in the study area do not preferentially prey on livestock.

Filling the gaps on the maps: historical distribution patterns of some larger mammals in part of southern Africa

Distribution data form the basis of the study of zoo-geography, which has applications in, inter alia, ecology and conservation. Written records were used to estimate the distribution patterns of some of the medium- to large-sized terrestrial mammals in central, southern and western South Africa, and neighbouring Lesotho, during the early historical period (late 1400 s to the 1920s). The sources of these records comprise mainly published or unpublished letters, journals, diaries or books written by literate pioneers – notably various missionaries, explorers, travellers, naturalists, military personnel, big game hunters and agro-pastoralists. The classification (according to record type) of the written records in key publications was standardised, and records overlooked by them are taken into account. Interpretation of the spatial patterns provided by the written records was aided by reference to supporting information, in the form of qualifying palaeontological, zoo-archaeological and museum records. Written records of acceptable quality are shown, together with supporting records (where applicable), on a series of species occurrence maps, which also depict the biomes that are represented in the study area. The information on these maps is interpreted, together with relevant information in the source texts and a map of the bioregions that constitute the biomes in question, to estimate distribution patterns that prevailed during the period under study. Data are presented for 27 genera, 36 species and 2 subspecies, comprising 7 carnivores and 30 herbivores. Despite the limitations associated with the use of written records, the information provided is considered to offer a realistic distribution pattern for most of the taxa covered. The use of supporting records is justified, since the majority of these corroborate the ranges derived from the written records. The present study enhances our knowledge of distribution patterns for these larger mammal species in a large part of the southern African sub-region during the early historical period. It also provides a first attempt to describe the sub-regional scale, historical, distribution patterns within the context of the broad biogeographical characteristics of the area in question. There is a need to extend the coverage achieved by this study to include the remaining approx. 30% of “South Africa”, i.e. the region incorporating South Africa, Lesotho and Swaziland, and also the area incorporated by the countries of Namibia, Botswana, Zimbabwe and Mozambique. This level of coverage will permit enhanced definition of historical distribution patterns for some larger mammals in the southern African sub-region. There is also a need to better understand the drivers, as well as the implications, of the observed changes in the distribution of the larger mammals since the start of the historical period.

On the distribution and breeding status of the Cape Griffon Gyps coprotheres in the Eastern Cape province, South Africa

The Cape Griffon Gyps coprotheres, a southern African endemic, is considered to have undergone an overall decrease in range and numbers. To track the species’ status, and to evaluate the impacts of conservation actions, it is periodically necessary to determine spatial and temporal patterns and trends in its population. Such information is provided for its Eastern Cape province, South Africa, population for the 2000–2007 period. Its range in this region is similar to that in the 1987–1992 period. The historical and current status of 143 roost sites and breeding colonies was established from the literature, anecdotal evidence or fieldwork. The western part of the province was, and still is, predominantly a foraging area. All currently active colonies are in the eastern part and within or close to communal farming areas. Of the historical sites in the western part, 76% are now inactive and most of the active sites are but seasonal/occasional roosts. Nearly half of former roosts are now inactive and 39% of former colonies have become inactive, or roost sites. The majority of colonies are small (<21 active nests). A minimum of 630 breeding pairs exists. The theoretical circumstances of the main findings are briefly discussed. The future existence of the species in the province is considered to be precarious.

Lost Herds of the Highveld: Evidence from the Written, Historical Record

Establishing historical baselines is important for informing present-day conservation and management actions. The historical literature was searched for information on the composition, abundance and distribution of the large ungulate fauna in the grassland-dominated Highveld region of north-central South Africa during the 19th century and early 20th century. The existence of large aggregations (herds comprising one or more taxa) is inferred from the written record, for the early historical period. These aggregations comprised one or more species of eight grazers or mixed feeders. There is weaker evidence of seasonal migratory, or partially migratory, behaviour by some of them. This synthesis highlights the existence of a major, but hitherto unrecognized and unheralded, grazergrassland system in the region, at least during the early period of colonial expansion. In global terms, this system may have rivalled similar extant migratory systems elsewhere in Africa and globally, if not in the numbers of animals involved then almost certainly in terms of the diversity of ungulates that were present. No records of large ungulate aggregations, or migrations, could be located for the post-1870s period, thus revealing the time of the collapse of this system, mainly as a result of overhunting and loss of habitat. By the end of the 19th century the once widespread and abundant larger ungulate fauna of the Highveld had, barring a few individuals and small and scattered herds, of a few species, been virtually exterminated. Some ecological consequences of this collapse are briefly discussed.

Evidence of partial migratory behaviour by the Cape Griffon Gyps coprotheres

Migratory behaviour has been reported for several Old World vulture species, but not for the Cape Griffon (Cape Vulture) Gyps coprotheres. Analysis of opportunistically obtained Cape Griffon distributional data from the Eastern Cape province of South Africa showed that griffon location was dependent on time of year, corresponding to the breeding season (April–October) and the non-breeding season (November–March). This finding was corroborated by a survey of landowners/ managers in the so-called East Cape Midlands, wherein 59% of respondents who reported the occurrence of griffons had a level of interest and awareness that enabled them to note seasonal occurrences; all stated that the griffons were observed ‘only, or mainly, during the summer’, i.e. during the species’ non-breeding season. Further corroboration was provided by the results of systematic counts (over 12 consecutive months) at two roost sites in the Midlands area. At both sites, the griffons were absent during the autumn–winter period (breeding season) and present during the spring–summer period (non-breeding season). Since only a portion of the Eastern Cape population appears to migrate, the species is considered a partial migrant. The source of the griffons that migrate to the Midlands area is not known. The possible origins of the reported migratory behaviour are discussed.

Is diet adaptability a reason for the persistence of African Crowned Eagles Stephanoaetus coronatus in altered habitats

The dietary response of African Crowned Eagles Stephanoaetus coronatus to habitat transformation was investigated. Habitat alteration around nests in the Eastern Cape, South Africa, was mapped and nests were assigned to two habitat classes. Prey remains were collected from around nests and identified by comparison with reference specimens and images and descriptions from the literature. Prey proportions were compared between ‘intact’ (n = 6) and ‘altered’ habitat classes (n = 6), and the Shannon–Wiener diversity index was calculated for each. Notwithstanding bias associated with the use of prey remains to investigate diet, the aims of the study were achieved. Rock Hyrax Procavia capensis was the primary prey in both habitat classes. In ‘altered’ habitats, the eagles took a larger proportion of species that are associated with open (e.g. hares Lepus spp.) and altered habitats (e.g. Vervet Monkey Chlorocebus pygerythrus) and a lower proportion of forest specialist species (e.g. Blue Duiker Philantomba monticola). Diet diversity was significantly higher in ‘altered’ habitats. Our data suggest that persistence of the eagles in altered landscapes can be attributed to two main factors: continued availability of a principal prey species and the ability of the eagles to respond to changes in availability by prey switching.