No Room to Grow

200 too many elephants? Says who? Understanding the dangers and devastation elephants pose to their own habitats when populations grow out of control.

August 13, 2018

9:22 am

Global concern for the welfare of elephants is often appropriately focused on both poaching and their depressingly dwindling numbers in the wild. Usually overlooked, though, is what happens when elephants live in areas that are adequately protected from poaching.

The good news is that we know elephants can thrive and repopulate when they're not endangered by people killing them for their tusks. The bad news is that, when unchallenged in their growth, elephants can reach capacity and overwhelm a habitat. Given their size and not always knowing their own strength, having too many elephants can be a devastating problem.

Maputo Special Reserve welcomed back 46 oribi and 21 eland. This is the first time that eland have been present in the park in more than 30 years.

The sable and oribi were translocated as part of a larger rewilding effort that saw 388 animals moved from Gorongosa National Park, Mozambique.

The eland were sourced from South Africa.

The rewilding season also saw the translocation of various other species to augment existing populations, that include elephant, giraffe, zebra and buffalo.

“Just as there are consequences for bad conservation management, there are also consequences for good conservation management,”

Kester Vickery, co-founder of Conservation Solutions.  

In this case, the consequence is that, if elephants multiply unchecked, they will ultimately destroy the ecosystems that house them, making reserves and protected areas not just uninhabitable for the elephants, but for all the other animals and plants with which they share their space.

This is particularly true in South Africa, one of a handful of countries in Africa with a thriving elephant population. One reason for South Africa’s elevated elephant numbers is that it is one of the only countries on the continent to allow private ownership of game and game parks. Another reason is that South Africa is one of the only African countries to use fences around its parks. In combination, these two factors have helped curb poaching -- but they’ve also hindered elephants’ natural migration patterns. So whereas under normal circumstances, elephants would spread out to wherever water and food was available, in South African parks, they can quickly grow to capacity.

As then-South African environmental minister Martinus van Schalwyk told The Guardian in 2008, “The elephant has been a victim of its own success.”

So how do conservationists save these elephants from themselves?

The first step is: do the math.

All parks, whether confined by fences or not, have a “carrying capacity,” which determines the numbers of a given species that that park can sustain. How does one determine carrying capacity? “Know what they eat,” says Dr. Corne Anderson, Ecology Manager at De Beers Group, which owns a half-dozen nature reserves in South Africa, including Venetia Limpopo. “Know what they eat and then look at the viability of the soil.” Of course, there are X factors that can change a carrying capacity rather unexpectedly, like drought, but according to Dr. Anderson, it’s not difficult to see evidence of overpopulation.

“You look for the destruction of trees, the emaciation of other species. It’s not hard to find. Elephants make themselves known.”

Dr. Corne Anderson, Ecology manager at De Beers Group

Up until recently, when there was a need to reduce elephant numbers to maintain capacity, the main solution was culling.

Parks like Kruger National Park in South Africa had active culling policies up until a decade ago. While a handful of conservationists maintain that culling is the most thoughtful solution for elephant sustainability, most others vehemently insist that culling can negatively impact elephant populations for decades to come, effectively traumatizing the survivors of a culling and changing their behavior patterns.

The international community generally agrees with most conservation groups in coming down firmly against culling. That helped take culling off the table as a viable option for most parks or reserves -- especially ones that cared about their relationship with the public.

Another option to keeping elephant numbers in line with capacity is birth control.

Not so much a solution to elephant population increase as a stop gap, elephant birth control is seen as a population-management tool. Administered by dart guns via helicopter and only to female elephants over 10 years of age, birth control has helped to stymie the rate of elephant reproduction. However, it does not altogether curb population growth. Nor is it without its consequences. Elephant herd structure revolves around newborn calves, and having fewer calves can result in altering herd behavior. Despite this, many conservation managers continue to rely on it to manage their populations.

Now, assisted migration is considered by many to be the socially responsible choice.

Animal translocation -- also called assisted migration -- is the process of removing animals from a place where they are overpopulated and moving them to a place where they are underpopulated. It is also used to relocate problem elephants and to move elephants that are in danger of coming into conflict with humans. The difference between animal translocation and species introduction is that, with translocation, animals are being relocated to areas where scientists know that they have already naturally occurred. Certain conservationists fear the unintended consequences that might come with assisted migration but, aside from killing the elephants, it often remains the only real option.

With climate change threatening animal habitats, assisted migration may be the only choice to stop extinction. The effects of climate change almost ensure that without human interventions, we will see the extinction of many species. As temperature changes make certain places inhabitable, translocation can make new, alternative homes palatable. The only available choice for saving animals from human-made impact is human intervention.