P Lee

Recorded incidence of conflict between humans and elephants, in particular crop-raiding, is increasing in rural Africa and Asia, undermining efforts to conserve biological diversity. Gaining an understanding of the underlying determinants of human–elephant conflict is important for the development of appropriate management tools. This study analysed crop-raiding by African elephants (Loxodonta africana) in Laikipia District, covering 9700 km2 in north-central Kenya to identify spatial determinants of crop-raiding by elephants at different spatial extents. On average crop-raiding incidents occurred within 1.54 km of areas of natural habitat where elephants could hide by day undisturbed by human activities (‘daytime elephant refuges’). The occurrence of crop-raiding was predicted by settlement density, distance from daytime elephant refuges and percentage of cultivation. However the relationship between crop-raiding and six candidate variables varied with sampling extent, with some variables diminishing in importance at a finer spatial scale. This suggests a tiered approach to human-elephant conflict management, with different interventions to address factors important at different spatial scales. Our results show that small-scale farms are particularly vulnerable to crop-raiding at settlement densities below approximately 20 dwellings per km2, above which crop-raiding declines. Land-use planning is therefore critical in preventing settlement patterns that leave farms vulnerable to crop-raiding by elephants. Where human–elephant conflict exists, efforts should focus on identifying and managing elephant refuges, through the use of electrified fences where resources are sufficient to construct, maintain and enforce them. This approach has been adopted for mitigating human–elephant conflict in Laikipia and with a major investment in resources and human capital it has been successful. Where such resources and human capital are not available then efforts should instead focus on the application of farm-based deterrents among vulnerable farms.

Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by h...