Population Survey

In Kenya, Tsavo Ecosystem comprises the largest contiguous protected area (Tsavo East and West and Chyulu National Parks and South Kitui National Reserve), measuring over 23,000km2. It adjoins important wildlife conservation regions, including the Taita, Galana, and Kulalu Ranches. The ecosystem hosts the largest elephant population in Kenya. Besides, a diverse array of other wildlife species, including numerous herbivores, carnivores and birds, are found in this region. However, the ecosystem is under pressure from anthropogenic influences as the human population grows, threatening sustainable biodiversity conservation of the region. As a result, the Kenya Wildlife Service (KWS) and other conservation partners have monitored wildlife numbers through aerial counts over a long period. During this year's total count, KWS and Wildlife Research and Training Institute (WRTI) and stakeholders joined efforts to count all large and medium-sized mammals within the ecosystem, including enumeration of human influences. The census lasted for seven days and covered 44,270 km2 using Fifteen aircraft (15) consisting of four-seaters (Cessna) and two-seater (husky) planes. Pilots flew transects at one (1) km and two (2) km spacing. The total count time was 280 hrs 44 minutes which translates to a search effort of 157.9 km2/hr. The crew spent an additional 136 hrs and 58 minutes transiting to and from the counting blocks. Nineteen (19) wildlife species were counted during the June 2021 census in the Tsavo Ecosystem, of which one (1) was avian and the rest herbivorous species. The most abundant species (>2,000 individuals) were the common zebra (17,964), elephant (14,879), buffalo (8,051), eland (4,635), giraffe (4,314), oryx (3,997), Hartebeest (2604), impala (2,660) and Grant's gazelle (2,172). A total of 74 and 55 critically endangered Hirola antelopes and Grevy’s zebra respectively were counted in the ecosystem, and all were confined to the Tsavo East-South region. Maasai ostrich the only avian species counted through the aerial census method recorded 510 individuals. A total of 468 dead elephants were recorded, representing a carcass ratio of 3.1% for the ecosystem. This report focuses on the species for which aerial censuses are suited thus, none of the carnivores, and avian except ostrich and aquatic species were included in the report. Human-related activities recorded during the census include livestock incursion, charcoal burning, logging, and mining that impact wildlife habitats negatively. A total of 156805 cattle, 128738 shoats (sheep and goats), and 22067 camels were estimated in the ecosystem. Livestock encroachment was noticed in the south of Tsavo West National Park and South Kitui National Reserve. Notably, no camels were recorded in the national parks; instead, they were concentrated in the ranches - Galana, Taita, and South Kitui National Reserve.