BLANTYRE, Malawi ― In 2012, African Parks, a conservation nonprofit, brought three lions to Malawi’s Majete Wildlife Reserve, ending the big cats’ 30-year absence from the protected area.

Since then, according to park officials, the number of lions has increased to about 80-100 today, raising the risk of prey depletion and conflict between humans and wildlife as the animals flee from the top predators.

To minimize these risks and ensure balance in the ecosystem, African Parks has been administering contraceptives since 2022 to reduce the productivity of some lionesses and control the population in the 700-square-kilometer (270-square-mile) wildlife reserve, and that has led to a reduction in cub births.

“The management strategy focuses on maintaining ecological balance, ensuring that predator and prey populations remain sustainable,” says Craig Thomas, conservation manager at the reserve.

Established in 1951, Majete Wildlife Reserve in southern Malawi suffered decades of rampant charcoal production and poaching that wiped out all rhinos by the 1980s, all large carnivores by the 1990s and all elephants by 1992 when the last one was poached, according to the wildlife reserve’s conservation history.

In 2003, African Parks signed an agreement with the Malawi government and assumed management of the reserve, the first of the 23 protected areas currently under African Parks’ responsibility in 13 African countries including Benin, Central African Republic, Chad, the Republic of Congo, the Democratic Republic of Congo, Ethiopia, Mozambique, Rwanda, South Sudan, Sudan, Zambia and Zimbabwe.

Among the restoration initiatives was the introduction in July 2012 of three lions from South Africa. The aim was to “boost Majete’s attraction as a wildlife destination” and as “the final step in the transformation of this once depleted park into a thriving ‘Big Five’ reserve,” according to a statement issued Aug. 17, 2012, about the translocation.

The arrival of the lions crowned earlier reintroduction of elephants, African buffalo, leopards and rhinos in the Big Five species as well as smaller animals such as African wild dogs.

The reserve is now home to more than 12,000 large mammals and other species, which ensures prey availability for the lions. As one recent study shows, high herbivore prey availability leads to high productiveness in the predators.

The rising lion population is posing risks as the park reports more than 3,000 animals falling prey annually and some breaking out into neighboring villages as they flee from the lions.

African Parks introduced a lion contraceptive program in 2022, using deslorelin synthetic hormonal implants to suppress reproductive cycles in female lions, preventing them from becoming pregnant for approximately two years, according to Thomas.

“Only specific lions were selected for contraception. The primary candidates were adult females of breeding age, and the treatment was applied to about 80% of the population,” Thomas tells Mongabay.

In selecting candidates for the birth control application, African Parks considered females that had already had litters, ensuring they had contributed to the gene pool and the need to space out the births at more natural intervals to replicate a system closer to what would occur without intervention.

“This approach also mitigates issues such as infanticide, increased immigration and uncontrolled population growth, all of which can have broader ecological implications,” Thomas says.

As a result, in 2024, no births occurred, and only three cubs were born in 2023, compared with the previous 8-10 cubs per year.

According to Thomas, controlling the lion population reduces human-wildlife conflict as large lion numbers put pressure on other animals that might then break out of the park.

“We also have a reduced prey depletion rate and, therefore, prey populations are staying at a more sustainable number. Lions are apex predators, meaning they don’t have natural predators themselves; therefore, their populations need to be managed,” he says.

Thomas notes that the method disrupts the natural growth of the population, but the park has not recorded negative behavior or psychological impacts on the lions.

“The effectiveness of this method is also demonstrated in other parks managed by African Parks, where similar programs have successfully controlled lion populations without negatively impacting pride dynamics.

“Furthermore, this strategy aligns with the broader concept of metapopulation management, which connects fragmented populations across large landscapes to enhance genetic diversity and long-term species survival,” Thomas says.

He adds that the approach enables lions to fulfill their natural ecological role in regulating prey populations, preventing overpopulation and associated habitat degradation.

Susan Miller, a scientist in the Department of Biological Sciences at the FitzPatrick Institute of African Ornithology at the University of Cape Town in South Africa with an interest in leveraging scientific methods to address conservation issues, particularly in the realm of genetics, says contraception can slow birth rates in African lions by increasing the age of first reproduction or the intervals between births.

“The goal of lion management in smaller fenced areas where some of the natural systems have broken down should be to mimic those natural processes. With lionesses, their interbirth intervals, age of first reproduction and cub survival rates are all altered from that of open systems, [which] leads to higher growth rates,” she tells Mongabay.

In a 2019 study, Miller and 14 other researchers assessed the effectiveness of two methods of contraceptives for reducing cub births in managed wild African lions: deslorelin implants and a unilateral hysterectomy in which surgery is undertaken to remove some reproductive organs.

Among the key findings was that deslorelin implants increase first reproduction age, lengthen inter-birth intervals, decrease litter size and increase weight gain in lionesses, with side effects increasing with successive implants.

With the surgery approach, the study found a “not statistically significant” decrease in litter size but no behavioral or physiological side effects.

“Deslorelin treatment was more effective in reducing the reproductive output of managed wild lionesses than unilateral hysterectomy surgery. While more side-effects were associated with deslorelin implants than unilateral hysterectomies, a single deslorelin treatment is currently a good option for fecundity reduction,” the study says.

Brighton Kumchedwa, director of Malawi’s Department of National Parks and Wildlife, says controlling the growth of the lion population shows that Majete Wildlife Reserve has now transformed from being a depleted habitat to a favorable environment for lions and other species.

“We know that this contraception method does not mean that the lions will never give birth. If more population is needed, these lions can be called upon,” Kumchedwa says.

“In addition, this is a humane way, as it does not lead to loss of life of the lions. They will keep enriching our biodiversity and contributing to tourism. As a department, our goal is to see the restoration of lion population in the areas where they once existed,” he says.

Return of the lions: Large protected areas in Africa attract apex predator

Citations:

Creel, S., Becker, M. S., Goodheart, B., Kusler, A., Banda, K., Banda, K., … Reid, C. (2024). Changes in African lion demography and population growth with increased protection in a large, prey‐depleted ecosystem. Conservation Science and Practice, 7(1). doi:10.1111/csp2.13256

McEvoy, O. K., Miller, S. M., Beets, W., Bodasing, T., Borrego, N., Burger, A., … Parker, D. M. (2019). The use of contraceptive techniques in managed wild African lion (Panthera Leo) populations to mimic open system cub recruitment. Wildlife Research, 46(5), 398. doi:10.1071/wr18079