Status and trends of the elephant population in the Tsavo-Mkomazi ecosystem

This paper updates the data on the population status of elephants in the Tsavo-Mkomazi ecosystem. Data were acquired through aerial census of elephants in the ecosystem, from 7 to 12 February 2011. The census covered an area approximately 48,319 km(2), which was divided into 44 counting blocks. Each block was assigned to a specific aircraft; the crew consisted of a pilot, front-seat observer and two rear-seat observers for the four-seater light aircraft, and a pilot and an observer for a two-seater light aircraft. The census lasted five days and involved nine light aircraft and about 252 hours of actual counting time, representing a mean search rate of about 191 km(2)/hr. A total of 12,573 elephants were counted, indicating a modest increase of 2% after the 2008 census and a 96% increase after the 1988 census (n = 6,399). Most elephants (69%, n = 8,614 individuals) were counted inside the protected areas; about 31% (n = 3,859 individuals) were outside protected areas. About 50% of the elephants (n = 6,214) were in Tsavo East National Park, 22% (n = 2,751) in the Taita ranches and 17% (n = 2,142) in Tsavo West National Park. A programme of providing water to elephants in the northern parts of Tsavo is recommended as well as electric fencing and establishment of administration and security structures at South Kitui National Reserve. This will create more space for the increasing population of elephants as well as improve their security.