As human development and activity increasingly encroach on wild habitats, one of the most challenging parts of protecting wild animals from suffering is figuring out solutions for coexistence. In this shrinking wild world, elephants have a particularly hard time—in part because their ranges are so large. This is why we created a unique program to prevent killing elephants and to keep inherently tight-knit elephant families together.

Dr. Audrey Delsink, wildlife director for Humane Society International/Africa, recently returned from the field where she was delivering a special kind of fertility control agent to wild female elephants to help manage their populations and prevent cruelty, suffering and culling. Here’s her story:

Recently, I was in a helicopter hovering over herds of elephants in South Africa. Even though I’ve seen elephants many times, the vision always inspires sheer awe.

African elephants are the largest land mammals on earth. They can range many thousands of miles in the wild, depending on the season and terrain. While African elephant populations are declining across the continent, in South Africa they face a different challenge: Here, they are being squeezed into smaller and smaller pockets of their former home ranges due to habitat loss and conflicts with humans. Fenced into protected reserves, elephants now live in disconnected islands and can’t follow their natural movement patterns, such as seasonal migration. Within these enclosed reserves, elephants can quickly reproduce—their numbers can double every 10 to 15 years. So, some form of population control is necessary.

Measuring the number of elephants a certain natural area can accommodate is a much contested and complex issue. These megaherbivores are referred to as ‘ecosystem engineers’ because of their role in modifying and changing the landscape. These changes can be compounded by several factors, such as drought, poor management practices, skewed sex and age ratios leading to a preponderance of bulls. This may lead to elephants, mainly young bulls, breaking through the fences to roam. Elephant bulls naturally disperse from their natal herds when they are about 10 to 15 years old, and increased competition and suboptimal conditions may be driving factors. They often wander onto farmland or neighboring reserves where they are unwelcome—and in danger. Traditionally, the “solution” to these conflicts is to kill elephants.

Traditional population control methods have included culling and translocation. Killing elephants is obviously cruel, and it is also stressful for those animals who escape the cull. Culling is neither an ethical nor sustainable solution. Translocation is extremely costly and there are few conservation areas that qualify as suitable. To help save South Africa’s elephants from these fates, HSI/Africa, with funding from the Humane Society of the United States, runs an innovative program in which trained experts dart free-ranging elephants with what’s called an immunocontraceptive vaccine as a long-term, proactive management solution.

This non-hormonal contraceptive works by causing an immune response in the female elephant’s body which prevents them from becoming pregnant. We select breeding females based on their estimated age and size, and we only consider darting those individuals who have already given birth to their first calf. Since the program’s inception in 1996, the vaccine, which is locally produced at the University of Pretoria’s Veterinary Population Management Laboratory, has proven itself to be a viable, non-lethal elephant population management tool in South Africa.

In October of this year, HSI/Africa and its partner organization, Global Supplies, visited the beautiful Thula Thula Private Game Reserve in Zululand to administer the vaccine to their small population. In the field, the vaccination process is swift and easy. Before boarding the helicopter (provided by our aviation partner Heligistix) to fly over the reserve and locate the herd, I helped prepare the immunocontraception vaccinations with our project implementation specialist and partner, JJ van Altena of Global Supplies.

To help save South Africa’s elephants from being culled, HSI/Africa helps control elephant populations there by darting free-ranging female elephants with an immunocontraceptive vaccine. Here, Dr. Delsink helps prepare the immunocontraceptive vaccine.
Kim Mcleod for HSI/Africa

From the air, we darted the selected females with a dart that contains both the immunocontraceptive vaccine and a purple substance that temporarily marks the elephant’s skin so that it’s easy to tell who has received the vaccine. The dart itself falls out almost immediately, which means there is no need to anesthetize or immobilize the elephants for treatment, and the whole process is successfully completed in minutes. In this instance, we completed the entire vaccination administration within 40 minutes. Eleven free-roaming female elephants of breeding age received the contraceptive vaccine. After this first vaccination, and a follow-up booster dose a few weeks later, these elephants will only need a single booster once a year to maintain the contraceptive effect. When the vaccinations are stopped, the elephant returns to fertility.

From the air, female elephants are darted with the immunocontraceptive vaccine, which contains a purple substance that temporarily marks their skin so that it’s easy to tell who has received the vaccine. The dart falls out almost immediately, which means there is no need to anesthetize or immobilize the elephants for treatment.
Michelle Riley/The HSUS

Thula Thula is the 46th wildlife reserve to take part in our program. In total, we’ve administered the immunocontraceptive vaccine to 1,530 elephants in South Africa. Our first vaccinations to test population control were administered at the Greater Makalali Game Reserve in 2000. Twenty-two years later, this elephant herd continues to thrive as the benchmark population. We are proud to continue to monitor and support this population. Our immunocontraception program is now officially legislated by South Africa’s government, and nearly 50 elephant reserves have adopted this population control method over culling.

Our program is actively changing the way in which this species is being managed across South Africa, sparing these highly sentient and amazing creatures suffering and distress common with other population control methods. We work across a range of small to very large private, community, provincial and national parks, and considering that every breeding female can produce eight to 10 calves in her lifetime, the exponential effect is remarkable. Based on our current treatment numbers, that’s 12,000 to 15,000 elephant calves who won’t be at risk of suffering cruel treatment or culling in only one generation.

Our efforts are reducing or stabilizing growth rates, which is important in curbing increasing population pressure and incidents of elephant conflict. Rather than seeing members of this iconic species being killed off through culling programs, which have massive, reverberating consequences for elephant genetics and social behaviors, our program is preventing suffering and keeping elephant families together.

Over the course of a quarter century since its launch, our immunocontraception initiative has transformed elephant management in South Africa. Immunocontraception represents an elegant and sophisticated solution to human-wildlife conflict, one that promises to take even deeper root in the future.