Umbrella species are 'species with large area requirements, which if given sufficient protected habitat area, will bring many other species under protection'. Historically, umbrella species were employed to delineate specific reserve boundaries but are now used in two senses: (1) as aids to identifying areas of species richness at a large geographic scale; (2) as a means of encompassing populations of co-occuring species at a local scale. In the second sense, there is a dilemma as to whether to maximize the number or viability of background populations; the umbrella population itself needs to be viable as well. Determining population viability is sufficiently onerous that it could damage the use of umbrella species as a conservation shortcut. The effectiveness of using the umbrella-species concept at a local scale was investigated in the real world by examining reserves in East Africa that were gazetted some 50 years ago using large mammals as umbrella species. Populations of these species are still numerous in most protected areas although a few have declined. Populations of other, background species have in general been well protected inside reserves; for those populations that have declined, the causes are unlikely to have been averted if reserves had been set up using other conservation tools. Outside one reserve, Katavi National Park in Tanzania, background populations of edible ungulates and small carnivores are lower than inside the reserve but small rodent and insectivore abundance is higher. While we cannot compare East African reserves to others not gazetted using umbrella species, the historical record in this region suggests that umbrella species have been an effective conservation shortcut perhaps because most reserves were initially large and could encompass substantial populations of background species. It is therefore premature to discard the local-scale umbrella-species concept despite its conceptual difficulties.

Data are presented on the demography and reproductive success of cheetahs (Acinonyx jubatus) living on the Serengeti Plains, Tanzania over a 25-year period. Average age at independence was 17.1 months, females gave birth to their ®rst litter at approximately 2.4 years old, interbirth interval was 20.1 months, and average litter size at independence was 2.1 cubs. Females who survived to independence lived on average 6.2 years while minimum male average longevity was 2.8 years for those born in the study area and 5.3 years for immigrants, with a large proportion of males dispersing out of the Plains population. Females produced on average only 1.7 cubs to independence in their entire lifetime and their average reproductive rates were 0.36 cubs per year or 0.17 litters per year to independence. Variance in lifetime reproductive success in the cheetah is similar to that of other mammals.No signi®cant negative correlations were found between adult cheetah population size and numbers of cubs reaching independence, implying that the Plains population had not reached carrying capacity. Annual numbers of adult female cheetahs only were correlated with rainfall. Adult female cheetah numbers were not correlated with adult female lion numbers on the Plains, however, reproductive rates of cheetahs were negatively correlated with the presence of lions while cheetahs had cubs. Moreover, cheetah reproductive success was lower during the period of high lion abundance (1980±1994) than during the earlier period of relatively few lions (1969±1979). Litter size at independence dropped from 2.5 to 2.0, lifetime reproductive success declined from 2.1 to 1.6 cubs reared to independence, and the reproductive rate (cubs/year) decreased from 0.42 to 0.36 from the earlier to the later period.Cheetah reproductive success showed little association with the presence of Thomson's gazelle at sightings except for a negative correlation between large numbers of gazelle (200±500) and reproductive success possibly because hunting success decreases with increasing prey herd size, or because cheetahs always lose in direct competition with other predators which are attracted to large congregations of prey. In addition, cheetah reproductive success was negatively correlated with the presence of Grant's gazelles (11 or more) perhaps because Grant's gazelles were more likely to occur consistently in dry areas.

Summary 0[ In Africa the majority of conservation areas sanction some sort of human activities within their borders but few of them are part of community!based conservation schemes[ The e}ectiveness of these state!owned\ partially protected areas in conserving mammalian fauna is largely unknown[ 1[ Large and medium!sized mammal densities in three di}erent sorts of partially protected area were compared to mammal densities in an adjacent national park in western Tanzania by driving 1842 km of strip transects over a 03!month period[ 2[ In a Game Controlled Area that permitted temporary settlement\ cattle grazing and tourist big game hunting\ mammal diversity and mammal densities were relatively high[ In a Forest Reserve that permitted limited hardwood extraction and resident hunting\ most large species were absent[ In a third\ Open Area that allowed settlement\ cattle grazing\ _rewood collection and beekeeping activities\ mammal diversity and densities were again low but some large ungulates still used the area seasonally[ 3[ The chief factors responsible for lowered mammal densities outside the Park were illegal hunting\ especially in close proximity to town\ and to a lesser extent\ resident hunting quotas that were too high[ 4[ These data suggest that state!owned conservation areas permitting human activities within their borders cannot be relied upon as a means of conserving large and middle! sized mammals in Africa[ 5[ Two methods are being employed to ameliorate this problem in Africa] excluding people from conservation areas while upgrading ground protection e}ort\ and initiation of community!based conservation schemes[ As yet\ however\ very few quan! titative data are available to evaluate the e.cacy of these methods in enhancing mammal populations[ Key!words] human impact\ mammal densities\ miombo woodland\ multiple!use areas\ national park[ Journal of Applied Ecology "0888# 25\ 194Ð106

Patterns of territory ownership in male cheetahs inhabiting the Serengeti Plains are described, and factors affecting territorial behaviour are examined. Body size and age were factors influencing whether males became territorial, and single males usually had to join up with others in order to oust residents. Both size of male coalition and body size of its members were associated with length of tenure on territories. Limited data suggest that territory owners were probably no more likely to encounter females than were non‐territorial males but there was a suggestion that they suffered lower survivorship costs than non‐territorial males.