Size Matters: Elephant contraception

Welgevonden is a magnificent game reserve in South Africa’s Limpopo Province. Its surface area is larger than the land mass of Malta, Grenada and eight other United Nations member states. The reserve’s colossal 375 km² footprint sounds like ample space for all species to thrive without the need for human meddling. But it’s not. I shared some phenomenal wildlife sightings with my parents whilst at Welgevonden last month, but we saw no calves ambling among the elephant herds. As we discovered, Welgevonden’s female elephants have been on contraceptives for the last eight years. Despite its impressive size, in elephant terms Welgevonden is still too small to allow them to breed freely. The same applies with most South African reserves which elephants call home.

The elephant problem

It’s often said that South Africa has an elephant problem. There are so many of them that we’re running out of space. At first glance, it doesn’t seem like a bad problem to have. But when elephant populations grow beyond healthy ecological limits, the impact they have on trees in their environment through uprooting and debarking can become so extensive that other species and the ecosystem as a whole suffers considerable and unsustainable damage.

The most frequently discussed approaches to counter an excess of elephant are translocation, culling and contraception.

Elephants from the darting helicopter (note the dye on the closest elephant's rump - marking that she's been darted). Credit:André Burger


Elephant translocation is a ferociously expensive undertaking, although funding can be found for it. That said, when Welgevonden translocated elephants in the past the reserve “basically had to pay to get rid of them” so Welgevonden’s Conservation Manager, André Burger, told me. André also explained that the far bigger issue is the almost complete lack of demand for free-roaming elephants. There’s nowhere for them to go and this is why translocation is so rarely an option. Contraception is therefore currently the only non-lethal alternative to culling.

Elephant immunocontraception: family planning

In 1994, fifty elephants were reintroduced at Welgevonden. It was the first time since the 1920s that the giant pachyderms had wandered Welgevonden’s undulating veld. Those pioneer elephants thrived, but as their number proliferated, so too did their collective impact on the reserve’s flora. If elephant numbers had been allowed to grow naturally, the consequences for biodiversity would have been devastating. In just a few years numbers “quickly went up to around 100, so we had to start thinking about contraception” André explained.

In 2005 Welgevonden started a program known an immunocontraception. This is a method of birth control involving injecting elephant cows with a vaccine triggering an immune system response. It prevents sperm from fertilising eggs. The vaccine, PZP, is administered by darting elephant cows from a helicopter, with an annual booster needed in following years.

André told me that elephant immunocontraception begins “with 13 year olds, but we had a calf born by an 11 year old.” Unwanted youth pregnancies are not exclusively a human issue. In future, Welgevonden will be starting PZP at an earlier age.

Should Welgevonden be enlarged, or the elephant population fall naturally, elephants will use fewer resources. Since immunocontraception is reversible, by not darting elephant cows with the annual booster, planned pregnancies can be allowed when resources allow. This is also important for the maintenance of elephant social structure, which, of course, requires the presence of calves.

Conservationists do not want to dart elephants with PZP. But in the absence of additional land being made available for conservation, contraception is the only realistic non-lethal option.

Immunocontraception is far more widespread than most people realise. Early trials took place in Kruger National Park and today PZP is used at famous South African conservation areas including Tembe, Thornybush, Phinda, Greater Makalali, Amakhala, and Mabula. Research has shown that after ten years of use, the vaccine has close to a 100% success rate of preventing unwanted pregnancies.


The human problem

Sure, it’s the elephants who are uprooting the trees. But blaming the animals knocking down the trees and not looking at the root causes ignores the human impacts.

In the 1890s, a catastrophic outbreak of the infectious disease, rinderpest, devastated South African cattle and wild herbivore numbers. Scientists believe this exotic disease was probably introduced to South Africa via Abyssinia (in current day Ethiopia) where the Italian army, some believe intentionally, imported infected Indian cattle. The collapse in herbivores almost certainly allowed an unnatural quantity of tress to survive to maturity.

At the same time widespread hunting and poaching helped to obliterate elephant numbers. Just over a century ago only 100 or so elephants remained in the whole of South Africa, fewer than are protected at Welgevonden today. The increase in herbivores and the return to less frighteningly low elephant numbers, South Africa has around 20,000 today, has occurred within our lifetimes. It’s quite possible that we have a distorted view of what savannah would look like in a pristine state.

Even if we accept elephants are the tree destroyers, we should question why that’s so. With the exception of the elephants in national parks with unfenced international borders, every other South African elephant is entirely surrounded by fences. Historically, elephants have migrated over vast distances. Today, fencing corrals elephants within the little remaining land that is not developed for agriculture or other human land uses. Being trapped year-round in the same areas means there is no periodic relief for the veld to recover from the undeniable impact that these elephants have on their surroundings.

In addition, artificial water holes are almost invariably provided in reserves and national parks. This guarantees constant water provision, which is not typical of savannah habitats. In true savannah, periodic drought regularly leads to the death of some elephant calves. It certainly wouldn’t be ethical to periodically remove water holes from the existing reserves to simulate this natural pattern, but human land use again prevents elephants from living the way that they have evolved.

The so called elephant problem should be framed differently. Rather than saying South Africa has too many elephants, the truth is that there are too many of us humans using too great a share of the land. The quantity and quality of land we are prepared to allow elephants to use is simply too small and too fragmented for them to live unmanaged. With elephants, size matters. They need tracts of land immeasurably larger than current human population and consumption demands tolerates. It’s because of us that elephant cows need contraception.

With my parents out in the veld at Welgevonden

Too many?

Conservationists like André can teach people outside their field a great deal. They understand that Welgevonden, like all other parts of the world, has finite resources. They also know that when the number of any one particular species grows beyond certain limits that the environment for all others can be devastated. The parallels between elephants and mankind are easy to make.

In the long run, the only way for the elephants of Welgevonden and elsewhere to be taken off contraception on a permanent basis is for the vast majority of land not to be used exclusively for human use, as it is today. But given South Africa’s growing human population and the increasing domestic and international demand for the resources our rich landscapes hold, this is not going to happen any time soon.

Elephants are unwitting participants in family planning efforts. But these efforts demonstrate an important point rather well. Elephant numbers are kept at a level which doesn’t negatively affect all the other species with whom they share their habitat. Their environmental impact is kept at a sustainable level. If only the human herd could apply the same principles to themselves.