Home range sizes and space use of African elephants (loxodonta enyaor) in the Southern Kenya and Northern Tanzania borderland landscape

Abstract

The African elephant (Loxodonta africana) require vast areas to meet their survival needs such as food, mates, water, resting sites, and look up positions; the area referred to as home range. We collared 9 bull and 3 female elephants using satellite-linked Geographic Positioning System (GPS) collars in February 2013. Their movements were monitored up to April 2016 in the wider Amboseli landscape. We estimated their home ranges using 100% minimum convex polygon (MCP) and 95% Fixed Kernel Density Estimator (KDE) methods. A total of 48,852 GPS points were used representing 77% of the expected GPS points. This study revealed that bulls had a larger total home range size (MCP = 32,110km²; KDE = 3,170km² compared to females (MCP = 10,515km²; KDE= 3,070km²). The 95% confidence interval of the monthly range (95% KDE) for all elephants was 6,130to 7,025km²with the minimum and maximum range being 5,200and 7,790km²respectively. Females had smaller home ranges during the dry and wet season (MCP: dry = 2,974km²; wet = 1,828km²; KDE: dry = 2,810km²; wet = 3,070km²) than bulls (MCP: dry = 3,312km²; wet =13,288km²; KDE: dry = 2,960km²; wet = 3,720km²). The variations of the elephant home range could have been influenced by an interaction of factors including rainfall, human disturbances and land use(e.g., farms, settlements, road network, and fences),water availability, bush cover, food availability,and tracking period. The most important areas that had key habitats for elephants were scattered throughout the Kenya/Tanzania borderland. The Amboseli-Tsavo-Magadi-Natron-West Kilimanjaro elephant population roams within specific areas of the landscape. Trans-boundary efforts should be enhanced to ensure sound management of the elephant-habitat-people interface for continued well-being of the elephant population.