Brian K. Reilly

Management of hybridization in an endemic species: decision making in the face of imperfect information in the case of the black wildebeest—Connochaetes gnou

Hybridization between introduced and endemic ungulates, resulting from anthropogenic actions, has been reported for several species. Several studies of such events contain the common themes of extralimital movements, problematic phenotypic and genetic detection, and imperfect management. In southern Africa, the endemic black wildebeest (Connochaetes gnou) currently faces a serious threat of hybridization and introgression. This species survived near extinction and consequent genetic bottlenecks in the late 1800s and in the 1930s. Initiatives by private farmers followed by conservation authorities led to a dramatic recovery in numbers of this species. However, in an ironic twist, the very same advances in conservation and commercial utilisation which led to the recovery of numbers are now themselves threatening the species. Injudicious translocation has brought the species into contact with its congener, the blue wildebeest (Connochaetes taurinus), and in recent times, hybridization between the species has occurred at numerous localities in South Africa. Consequently, a significant proportion of the national black wildebeest population potentially carries a proportion of introgressed blue wildebeest genetic material. We discuss completed and ongoing attempts to find molecular markers to detect hybrids and highlight the difficulty of detecting advanced backcrosses. Additional avenues of research, such as work on morphology (cranial and postcranial elements), estimating of the probability of introgression and modelling of diffusion rates are also introduced. In addition to the difficulty in detecting hybrid animals or herds, the lack of consensus on the fate of hybrid herds is discussed. Finally, in an environment of imperfect information, we caution against implementation of management responses that will potentially induce a new genetic bottleneck in C. gnou.

Dams and Large Scale Irrigation on the Senegal River. Impacts on Man and the Environment

In the construction of the Diama and Manantali Dams, Senegal, constraints to large scale irrigation were not adequately taken into account, while to date planned artificial floods to assure the continuation of traditional production systems (e.g. recession agriculture, freshwater fish production, estuarine/marine fishery nursery grounds and dry season forage) have been inadequate in both magnitude and duration.

Politicization of land reform in Zimbabwe: impacts on wildlife, food production and the economy

Land reform is a major Southern Africa issue. Land reform, to rectify its inequitable distribution between white and black Zimbabweans, became radicalized by President Robert Mugabe and his political party ZANU‐PF as a means to stay in power. This has had adverse impacts on food production, conservation, use of wildlife, and both national and regional economies. Ill‐considered internal and regional policies that result in economic ruin and uncontrollable immigration by the poor, hopeless disenfranchised masses could end any hope for an African Renaissance. This would harm South Africa, and prevent it from providing the benefits of development to Africa’s people.

Wildlife road traffic accidents: a standardized protocol for counting flattened fauna

Previous assessments of wildlife road mortality have not used directly comparable methods and, at present, there is no standardized protocol for the collection of such data. Consequently, there are no internationally comparative statistics documenting roadkill rates. In this study, we used a combination of experimental trials and road transects to design a standardized protocol to assess roadkill rates on both paved and unpaved roads. Simulated roadkill were positioned over a 1 km distance, and trials were conducted at eight different speeds (20–100 km·h−1). The recommended protocol was then tested on a 100-km transect, driven daily over a 40-day period. This recorded 413 vertebrate roadkill, comprising 106 species. We recommend the protocol be adopted for future road ecology studies to enable robust statistical comparisons between studies.

A comparison between tick species collected in a controlled and control free area on a game ranch in South Africa

Despite the large number of collection records, there are no recent collections of ixodid ticks of this magnitude in the Waterberg area, Limpopo Province, South Africa. Free-living ticks on a commercial game farm were obtained by a total of 432 drag-samples in eight sample sites from September 2003 to August 2008. The ticks were collected to establish the difference between tick species and densities associated with acaricide-controlled (semi-intensive) and control-free areas on a game farm in the Thabazimbi District, Limpopo Province, South Africa. A total of eight tick species were collected, namely Amblyomma hebraeum, Rhipicephalus (Boophilus) decoloratus, Haemaphysalis elliptica, Hyalomma rufipes, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus zambeziensis and Rhipicephalus spp. The most abundant tick species collected was Rhipicephalus (Boophilus) decoloratus. The difference in species and numbers reflects the effectiveness of acaricide treatment against ticks and its relevance to tick numbers on a game farm.

Measurement and Recognition of Wildlife in the Financial Statements of Public Sector Entities: A South African Perspective

Wildlife is an environmental asset. However, the concept of financial accounting for wildlife in financial statements is questioned and various arguments are used to not account for it. For example, fauna moves from place to place which complicates counting, the cost of counting wildlife is expensive, monitoring, measuring, and managing of accounting values does not add value, and parks manage wildlife for conservation purposes not to generate profits.

Burrow structure and microhabitat characteristics of Nesiergus insulanus (Araneae : Theraphosidae) from Fregate Island, Seychelles

Abstract The burrow structure and microhabitat variables of the little known theraphosid Nesiergus insulanus Simon 1903 were determined on Frégate Island, Seychelles. The species constructed burrows in fossorial substrates, including rocks, leaf litter and bare soil as well as on the trunks of decaying trees, both recumbent and standing. The majority of burrows were predominantly found in sandy loam soil with partial protection from the sun. The density of burrows was determined to be weakly positively correlated to soil and substrate type and strongly negatively correlated to degree of exposure to the sun. The pH of the soil in which burrows are found was not significantly related to burrow sites, and variability in burrow structure was revealed. Burrow aggregations vary from single burrows to aggregations exceeding 100, distributed randomly.

The Distribution and Population Status of Nesiergus insulanus Araneae: Theraphosidae: Ischnocolinae) on Frégate Island, Seychelles

Summary The theraphosid Nesiergus insulanus is a member of a genus endemic to the Seychelles archipelago. Very little is known about the finer-scale distribution, density, and total population size of the species, knowledge of which is essential for conservation purposes. We used transect sampling to estimate these variables on Frégate Island. We show that the species is widely distributed, but geographically restricted as a result of fragmentation due to human activity. Where found, densities can be very high (>100 m-2). The total population on the island was estimated to be well over 100,000, although limitations to dispersal ability may be of conservation concern.

An Inventory of Vertebrate Roadkill in the Greater Mapungubwe Transfrontier Conservation Area, South Africa

Using a standard protocol, we conducted vertebrate roadkill surveys in the Greater Mapungubwe Transfrontier Conservation Area (GMTFCA), South Africa, which is a World Heritage Site. A total of 991 roadkill were recorded on the paved roads and 36 roadkill on the unpaved roads. Identifiable roadkill comprised 162 species from 24 orders and 65 families. Ninety-three roadkill could not be identified to species level. Roadkill counts were strongly influenced by road type and season. More roadkill was recorded on the paved than the unpaved roads. Irrespective of road type, the proportion of roadkill was greatest in the hot/wet season (4.3 paved roadkill/km/day paved and 1.3 roadkill/km/day unpaved) and lowest in the cold/dry season (2.0 roadkill/km/day paved and 0.1 roadkill/km/day unpaved). The high numbers of vertebrates identified as roadkill suggests that road traffic has the potential to directly and negatively affect biodiversity conservation in this part of South Africa. We recommend continued roadkill data collection across South Africa to assist with creating an inventory of species most likely to be at risk from roads. This will, in turn, better inform the implementation of potential mitigation measures.

Eco-Politics of Dams on the Gambia River

In the 1980s, USAID (US Agency for International Development) funded an environmental assessment of dams on the Gambia River, which determined that construction of the Balingho anti-salinity barrage would result in adverse unmitigative environmental and social consequences. Attempts by host country politicians, USAID and UNDP (United Nations Development Programme) to discredit this process made it necessary to take the matter to the Natural Resource Defense Council. A case study of the events surrounding these dams and their potential construction illustrates the ‘big dam’ paradigm and its potential harm to people, their livelihoods and the environment in Sub-Saharan Africa.