With limited space and a delicate balance of predator-to-prey and plant life, population control is an essential aspect of conservation in a game reserve. Lalibela Game Reserve in the Eastern Cape has implemented an effective contraceptive strategy for its lions and elephants, adding to its many conservation and community endeavours.
‘Our conservation efforts aim to meet the biological needs of the reserve while caring for the longevity and wellbeing of its animals,’ says Lalibela Conservation Manager Courtney Hicks.
Image: Supplied/Lalibela.
The implications of allowing animal populations to grow beyond their viable numbers are not to be taken lightly. ‘Overpopulation quickly leads to the depletion of prey species and the degradation of the habitat. When the numbers are no longer at a sustainable level, we have no choice but to reduce the pressure placed on the environment and other species within the reserve. Contraception allows us to maintain stability, focusing on prevention without disrupting the genetic diversity or social structures of the animals,’ says Hicks.
Elephants are particularly dependent on complex family systems that determine their behaviour and support their wellbeing. When non-lethal methods are applied to control their numbers, these social dynamics remain intact while maintaining an appropriate food resource and allowing the herd enough space to roam. Because of its size, Lalibela can support a maximum of 12 elephants, and pregnancy prevention is the perfect solution to keep the herd at this optimal number.
Image: Supplied/Lalibela.
A contraceptive vaccine is administered to fertile female elephants in the field through a non-invasive dart dispensed from a helicopter to ensure the safety of the rangers. Once received, the vaccine stimulates the growth of antibodies that bind to sperm receptors on the ova to prevent fertilisation. After a year, a booster shot is administered to maintain infertility. It is reversible and if an elephant no longer receives the vaccine, she can regain her fertility.
Lionesses reach fertility at two years old and continue to reproduce throughout most of their lifespan. When a reserve is overpopulated with lions, its ecological equilibrium is gravely affected. Prey species begin to deplete too fast and as a result the landscape begins to suffer. Maintaining a manageable number of lions is crucial to the stability of the ecosystem. By curbing lioness fertility, the small population at Lalibela is also prevented from reproducing too closely within its gene pool.
Deslorelin is a gonadotropin-releasing hormone implanted into lionesses. The hormone is gradually released over a period of months or years depending on the particular dosage and the population’s needs. Through continuous stimulation of the pituitary gland, deslorelin causes an initial surge in reproductive hormones, followed by a suppression phase where the animal’s reproductive system becomes inactive, leading to reversible short-term infertility.
Because conservation is at the heart of Lalibela, the team is committed to using scientifically-backed methods in the short-term to maintain a healthy ecosystem where animals and the environment can thrive and visitors can bear witness. The long-term goal, however, is to increase the reserve’s hectarage and take down the fences that separate it from neighbouring reserves that hold similar goals of environmental and animal conservation.
When this happens, the need for intervention through contraceptives will fall away. The animals will have increased land to roam and more resources to sustain their growing numbers. Until then, contraceptives provide a non-invasive and humane management tool to protect Lalibela’s landscape and its animals.
The reserve is known for its outstanding conservation initiatives supported by tourism, and dedicates 100% of its surplus revenue to the community. Six safari lodges blend seamlessly into five different habitats, providing a luxurious experience for its guests without causing disturbance to the fauna and flora. There are no public roads in the reserve, and animals roam freely throughout the grassland savannah. Lalibela is a fully protected, self-sustaining landscape and this island reserve is one of the jewels of the Eastern Cape.
Visit this link to learn more about Lalibela’s conservation, research, and land management efforts: https://lalibela.net/conservation-at-lalibela/.