Summary1. The resolution of direct con¯ict between humans and elephants in Africa has become a serious local political issue in recent years, and a continental conservation problem.`Problem elephants' damage crops, food stores and water sources, and sometimes threaten human life. 2. Eighty per cent of the African elephant's range lies outside formally protected areas, and inadequate management of human±elephant con¯ict is frequently a precursor to further decline in the numbers and distribution of elephants. Con¯ict appears to be increasing in an assortment of African ecosystems as the agricultural interface with elephant range expands. 3. The present study recorded incidents by problem elephants in small subdivisions of a 15 000 km 2 elephant range. The level of problem elephant activity over 3 years showed huge variation and could not be explained by elephant density, proximity of a protected area, area of human settlement, human density or local rainfall. 4. It is proposed that the irregular and unpredictable nature of human±elephant con¯ict incidents in the study area mainly depended upon the behavioural ecology of individual elephant bulls. 5. This study proposes a statistic to quantify problem elephant activity in Africa which can be used to compare the intensity of problem incidents between dierent ecosystems at dierent times:`elephant incidents per square kilometre of human settlement area per year'. Spatial analyses of appropriate data at the human±ele-phant interface may yield a more predictive understanding of the con¯ict process.

The decline in the range and numbers of elephants as a result of expanding human activity in Africa is recognized as one of the continent’s more serious conservation problems. Understanding the relationship between human settlement patterns and elephant abundance is fundamental to predicting the viability of elephant populations. The prevailing model of human‐elephant interaction predicts a negative linear relationship between rising human density and declining elephant density at a coarse (national or subcontinental) scale. Using observed elephant densities and human population data, we tested this prediction in a study area of 15,000 km2 in northwestern Zimbabwe. The results did not fit a linear model. Elephant and human coexistence occurs at various levels of human density, up to a threshold of human density beyond which elephant populations disappear. This threshold seems to be related to a particular stage in the process of agriculturally transformed land becoming spatially dominant over the natural woodland that constitutes elephant habitat. Within the contexts of conservation and sustainable development in African savannas, investigating spatial relationships between elephant and human abundance should be a priority topic for future research.

Summary 1.Knowledge of infection reservoir dynamics is critical for effective disease control, but identifying reservoirs of multi-host pathogens is challenging. Here, we synthesize several lines of evidence to investigate rabies reservoirs in complex carnivore communities of the Serengeti ecological region in northwest Tanzania, where the disease has been confirmed in 12 carnivore species. 2. Long-term monitoring data suggest that rabies persists in high-density domestic dog Canis familiaris populations (> 11 dogs km -2 ) and occurs less frequently in lower-density (< 5 dogs km -2 ) populations and only sporadically in wild carnivores. 3. Genetic data show that a single rabies virus variant belonging to the group of southern Africa canid-associated viruses (Africa 1b) circulates among a range of species, with no evidence of species-specific virus-host associations. 4. Within-species transmission was more frequently inferred from high-resolution epidemiological data than between-species transmission. Incidence patterns indicate that spill-over of rabies from domestic dog populations sometimes initiates short-lived chains of transmission in other carnivores. 5. Synthesis and applications . The balance of evidence suggests that the reservoir of rabies in the Serengeti ecosystem is a complex multi-host community where domestic dogs are the only population essential for persistence, although other carnivores contribute to the reservoir as non-maintenance populations. Control programmes that target domestic dog populations should therefore have the greatest impact on reducing the risk of infection in all other species including humans, livestock and endangered wildlife populations, but transmission in other species may increase the level of vaccination coverage in domestic dog populations necessary to eliminate rabies.

Morbilliviruses cause many diseases of medical and veterinary importance, and although some (e.g., measles and rinderpest) have been controlled successfully, others, such as canine distemper virus (CDV), are a growing concern. A propensity for host-switching has resulted in CDV emergence in new species, including endangered wildlife, posing challenges for controlling disease in multispecies communities. CDV is typically associated with domestic dogs, but little is known about its maintenance and transmission in speciesrich areas or about the potential role of domestic dog vaccination as a means of reducing disease threats to wildlife. We address these questions by analyzing a long-term serological dataset of CDV in lions and domestic dogs from Tanzania's Serengeti ecosystem. Using a Bayesian state-space model, we show that dynamics of CDV have changed considerably over the past three decades. Initially, peaks of CDV infection in dogs preceded those in lions, suggesting that spill-over from dogs was the main driver of infection in wildlife. However, despite dog-to-lion transmission dominating cross-species transmission models, infection peaks in lions became more frequent and asynchronous from those in dogs, suggesting that other wildlife species may play a role in a potentially complex maintenance community. Widespread mass vaccination of domestic dogs reduced the probability of infection in dogs and the size of outbreaks but did not prevent transmission to or peaks of infection in lions. This study demonstrates the complexity of CDV dynamics in natural ecosystems and the value of long-term, large-scale datasets for investigating transmission patterns and evaluating disease control strategies.cross-species transmission | multihost pathogens | reservoirs | state-space models | serology T he genus Morbillivirus includes highly contagious, and often fatal, RNA viruses that cause diseases of great public health, economic, and conservation concern, such as measles, rinderpest, and canine distemper. Canine distemper virus (CDV) is distributed worldwide and affects an expanding range of host species, including domestic and wild canids (1, 2), marine mammals (3), felids (2, 4, 5), procyonids and ursids (6), and nonhuman primates (7-9). The propensity of CDV for host-switching has raised concerns about both potential risks for humans (10) and extinction threats to endangered wildlife (11-13).Although previously thought to be nonpathogenic in cats, outbreaks among large captive felids in the 1990s drew attention to CDV as a potential conservation threat to felids (2). The beststudied example of CDV infection in free-ranging felids comes from Tanzania's Serengeti ecosystem (Fig. 1A), where a CDV epidemic in 1994 killed ∼30% of lions (Panthera leo) and affected several Significance Morbilliviruses are a growing concern because of their ability to infect multiple species. The spill-over of canine distemper virus (CDV) from domestic dogs has been associated with severe declines in wild carnivores worldwide, and therefore mass...

Summary1. Anthrax is endemic throughout Africa, causing considerable livestock and wildlife losses and severe, sometimes fatal, infection in humans. Predicting the risk of infection is therefore important for public health, wildlife conservation and livestock economies. However, because of the intermittent and variable nature of anthrax outbreaks, associated environmental and climatic conditions, and diversity of species affected, the ecology of this multihost pathogen is poorly understood. 2. We explored records of anthrax from the Serengeti ecosystem in north-west Tanzania where the disease has been documented in humans, domestic animals and a range of wildlife. Using spatial and temporal case-detection and seroprevalence data from wild and domestic animals, we investigated spatial, environmental, climatic and species-specific associations in exposure and disease. 3. Anthrax was detected annually in numerous species, but large outbreaks were spatially localized, mostly affecting a few focal herbivores. 4. Soil alkalinity and cumulative weather extremes were identified as useful spatial and temporal predictors of exposure and infection risk, and for triggering the onset of large outbreaks. 5. Interacting ecological and behavioural factors, specifically functional groups and spatiotemporal overlap, helped to explain the variable patterns of infection and exposure among species. 6. Synthesis and applications. Our results shed light on ecological drivers of anthrax infection and suggest that soil alkalinity and prolonged droughts or rains are useful predictors of disease occurrence that could guide risk-based surveillance. These insights should inform strategies for managing anthrax including prophylactic livestock vaccination, timing of public health warnings and antibiotic provision in high-risk areas. However, this research highlights the need for greater surveillance (environmental, serological and case-detection-orientated) to determine the mechanisms underlying anthrax dynamics.