Geospatial Patterns and Behavioural Responses of Elephants to Cattle and Mortality Risk in a Pastoralist Maasai Mara Landscape, Kenya

Abstract

The unprecedented pace and scale of anthropogenic changes to environments and direct species harvesting are causing substantial wildlife species declines globally. For many species, behavioural plasticity forms the first line of response to exploitation and environments altered by humans. Although behavioural plasticity can enhance survival in altered environments, maladaptive behavioral scenarios or “evolutionary traps” can threaten the persistence of some species from anthropogenic alteration. In elephants, poaching bias towards older individuals. Altered social structures and habitats may impact decision making of elephant social groups in anthropogenic landscapes creating maladaptive responses that can amplify conflict. In this study, we examined geospatial patterns of elephant mortality risk, cattle distribution, Normalized Difference Vegetation Index (NDVI) and habitat protection status on elephant distribution and group-sizes at the Maasai Mara National Reserve (MMNR), Community Wildlife Conservancies (CWC) and surrounding Community Grazing Lands (CGL) in the Maasai Mara ecosystem. We also investigated how social group type, group-size, age of the oldest individual in a group and habitat openness influence elephant response to experimental cowbells. Using kernel density analyses from ten years of georeferenced clinical reports pertaining to elephant injuries and elephant mortality due to poaching, we show that elephant injuries and mortalities were highest in CWC and CGL compared to MMNR. Our study showed a positive relationship between elephant group-size with NDVI, and the risk of elephant mortality or injury. Concealed cowbells played to elephants revealed that elephant aggression towards cowbells was not influenced by matriarch age, group-size, habitat type or status of habitat protection. However, defensive bunching was positively related to the matriarch’s age, group-size and social group type. These results suggest sensitivity of older matriarchs to poaching risk and that elephants use group defense or avoidance behavioural strategies irrespective of vegetation cover.