In addition to the black and white rhino, the Ol Pejeta Conservancy is home to a number of endangered species including the locally threatened Jackson’s hartebeest and Grevy’s zebra.
Grevy’s zebra (Equus grevyi): Grevy’s zebra are categorized as endangered on the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species and listed on Appendix I of the Convention on International Trade in Endangered Species (CITES). Current global population estimates are between 1,964 and 2,445. In Kenya alone, the population estimates are between 1,838 and 2,319. The Laikipia-Samburu ecosystem remains a vital area in the conservation of this species in Kenya. The Ol Pejeta Conservancy introduced 13 Grevy’s zebras to the fully fenced game reserve in the early 1990’s, of which only three remained. Later, 10 Grevy’s zebras immigrated from neighbouring ranches, and inhabited the western sector of the Conservancy. Three main threats face the Grevy's zebra population on the Ol Pejeta Conservancy: (i) excessive predation by lions; (ii) low population density; and (iii) skewed sex ratio. Studies of Ol Pejeta’s Grevy’s zebra population within the former enclosed Sweetwaters Game Reserve have shown that the survival rate of foals is 8.2%. Given this level of predation pressure in the Conservancy, coupled with a small population size, the Conservancy’s Grevy’s zebra population was considered nonviable and unlikely to increase. The small population was scattered widely over 300 sq km.
Further, there are more males than females. Mating opportunities are thus few and far between. The skewed sex ratio is one potential cause for the occurrence of Grevy's zebra/common zebra (Equus burchelli) hybrids. At least 22 hybrids have been individually identified. The Ol Pejeta Conservancy set aside a predator-free area of approximately 7,400 acres for the breeding of endangered species, especially Grevy’s zebras. Supported by the Kenya Wildlife Service, Ol Pejeta’s Wildlife Management Department between 3-10 March 2011, moved eight Grevy’s zebras from the wider conservation area into the endangered species enclosure in order to consolidate the population and increase chances of breeding. By separating the Grevy's zebra population from common zebra, the problem of hybridization will be eliminated.
To address the low population density problem and increase chances of Grevy's zebra breeding, Ol Pejeta, in collaboration with Lewa Wildlife Conservancy and Kenya Wildlfe Service, translocated eight female Grevy's zebra from Lewa to Ol Pejeta on 17th September, 2012. The Grevy’s zebras were released into the endangered species enclosure, bringing the total number in the boma to 15 (12 adult females and 3 foals). In future, females and their offspring can be translocated out of the endangered species boma into the wider conservation area to boost other small populations.
Jackson’s Hartebeest (Alcelaphus buselaphus lelwel): Jackson’s hartebeest are classified as Lower Risk: Conservation Dependent on the International Union for the Conservation of Nature (IUCN) Red List. They have small and mostly declining populations. The total population of Jackson’s hartebeest is unknown but in Laikipia their numbers are estimated at between 700-1000 individuals of which the Ol Pejeta Conservancy contains an estimated 188 individuals (27%). Predation by lions and spotted hyenas is thought to be the biggest factor causing the decline of the Ol Pejeta hartebeest population. The Ol Pejeta Conservancy aims to monitor the population to establish the predation pressure on hartebeest, and to enhance their breeding performance through establishment of a viable population within the same a predator-free enclosure as the Grevy’s zebras.
Cheetahs (Acinonyx jubatus): Cheetahs are listed as endangered and are on Appendix I of the Convention on International Trade in Endangered Species (CITES). Global estimates indicate that cheetah numbers have decreased from 100,000 in 1900 to as low as 12,000 to 15,000 in 1995, representing a decline of nearly 90% over the century. Cheetah numbers are declining due to loss and fragmentation of habitat, and a declining prey base. Predation of cheetahs by both lion and hyenas in protected game reserves is forcing larger numbers of cheetahs to live outside protected areas and therefore coming into conflict with humans. Other threats facing cheetahs include diseases and low genetic diversity. The cheetah population in Kenya is not well-known but is approximately 1,000 individuals. Currently, Ol Pejeta has a confirmed cheetah population of 28 individuals which are continuously monitored. Individuals are identified by their tail rings which are distinctive to each individual. This monitoring will help the management to better understand the population status of this species.
Spotted Hyenas (Crocuta crocuta): Spotted hyenas are classified as Lower Risk: Conservation Dependent on the International Union for the Conservation of Nature (IUCN) Red List. The world population of spotted hyenas is estimated at between 27,000 and 47,000. Despite these figures, the rapid decline of populations outside conservation areas due to persecution, disease (especially rabies) and habitat loss makes the species increasingly dependent on the continued existence of conservation areas. The spotted hyena plays an important role in the population regulation of prey species. However, this does depends on the area and many other factors. Spotted hyenas compete for prey with other species that are of special concern to the Conservancy such as lions, cheetahs, and leopards. On Ol Pejeta, spotted hyena numbers are estimated at 99 individuals currently.
Lions (Panthera leo): The conservation status of lions is considered vulnerable according to the International Union for the Conservation of Nature (IUCN) Red List. A population reduction of 30-50% is suspected to have occurred over the last 20 years mainly due to hunting, poisoning and habitat loss. The estimated number of lions in Africa is 23,000-39,000 with Kenya’s lion population being estimated at 2280. The Laikipia-Samburu ecosystem’s population is approximately 350 and is described as viable and stable. Ol Pejeta has a current population of 69 lions. Increased lion numbers means increased lion sightings by tourists. However, increased lion numbers are likely to have a negative impact on both cattle and herbivore populations. Ol Pejeta has to prevent the populations of major prey species from falling below sustainable levels as this would reduce the biodiversity of the Conservancy. Similarly, if prey abundance reduces to levels that can not sustain the lion population, there is a high risk of rhino calves being immediate targets for lion predation. The lion population therefore needs to be monitored so that appropriate preventative interventions can be taken to maintain a desirable equilibrium.
For more information on the Ol Pejeta Conservancy Endangered Species Programme, please contact firstname.lastname@example.org.