Captive Pterocles namaqua and P. bicinctus showed behavioural adaptations for thermoregulation and water conservation. Reduction of environmental and metabolic heat loads by day, and conservation of metabolic heat at night, were achieved by altering activity levels and by exploiting or creating appropriate microclimatic conditions.
The diurnal gecko genus Rhoptropus is typical to the northern Namib Desert and adjacent inland areas. Three species extend southwards into the Namib-Naukluft Park. A detailed survey of the distribution shows very diverging patterns for each of these species south of the Swakop River and this situation is discussed with reference to habitat preference related to stratigraphy, substratum and possible effect of competition with sympatric lizard species.
This paper documents the temporal and spatial incidence of veldfire in the Etosha National Park from 1970-1979. The data analysed indicate that most veld-fim are caused by lightning and occur chiefly from October-December. There were three times as many naturally caused fires in 1975- 1979 as in the preceding five-year period. Virtually all vegetated areas of the park burned at least once during the period 1970-1979. These and other findings are discussed in relation to climate and management practices.
Hyaena brunnea are found mainly along the coast while Crocuta crocuta range further inland being associated with Oryx gazeIIo and freshwater. Differences in latrines are descriptionbed and the scats or H. brunnea are significantly lighter than those of Crocuta (45,8 cf. 160,9; P<0,001). Analysis of identifiable prey remains showed that in H. brunnea scats Arctocephalus pussilus hair predominated (75%) cf. Crocuta scats in which Oryx gazelle hair (94,5%) predominated. Reasons for the geographical separation of the species are discussed.
Investigations between 1975-78 established that a combination of disease, namely anthrax, and excessive numbers of predators, especially Lion, were responsible for the sharp decline in wildebeest numbers. On average, 62 % of all wildebeest carcases tested positive for anthrax, while predators were not susceptible to anthrax. The levels of other disease and parasites were low.
Following a decline in the wildebeest population From 25 000 to 2 500 between 1954-78 it was established that the calving percentage was normal (22% of total population) but that disproportionate mortality, favouring the cows, resulted in 48% of recorded deaths between 3-6 years of age. By 10 years of age 91% of all adults had died. Disease, namely anthrax and abnormal predation levels caused this high death rate.