The large number of mature and experienced African elephants being killed illegally for their ivory is exposing younger surviving elephants to a higher risk of mortality from predation and other risks, wildlife conservationists said today.
Close monitoring of a thousand elephants in Samburu, northern Kenya, over the last 14 years has provided solid evidence of disruption of the social dynamics within families, according to Save the Elephants (STE), a Kenya-based conservation organization that conducted the research. “Over the last four years demand for their tusks has disrupted their close-knit society,” STE said in a news release about the study published today in the science journal PLOS One.
The STE research gives the first detailed analysis of the impacts of illegal killing on a well-studied population.
“Unfortunately, illegal killing and related population decline is increasingly common across Africa, therefore the results from this study are directly relevant to understanding the conservation status of this species,” writes George Wittemyer of Colorado State University and STE, who led the study.
“An unprecedented opportunity to investigate the effects of the killing by comparing times of stability with times of strife.”
“Elephants roam far beyond the safety of the reserves and into danger zones where ivory poachers are active,” Save the Elephants writes in a news summary about the project. “At the start of the research the population was increasing, but in 2009 the poaching of these individually-known elephants began to take its toll. This change gave researchers an unprecedented opportunity to investigate the effects of the killing by comparing times of stability with times of strife.”
Older Animals Killed in Larger Number
The proportion of elephants that were illegally killed doubled in the last three years of the study. “Older animals—usually those with larger tusks—fared particularly badly. In 2000 there were 38 known males over 30 years old. By 2011 this number had dropped to 12, of whom 7 had grown into the older age class. Almost half of the known females over 30 years old were lost between 2006 and 2011, their number dropping from 59 to 32. While some of this mortality was due to a severe drought that hit the area in 2009-10, at least half is thought to be due to illegal killing,” the researchers write.
The wave of killing altered the age structure and age-related social organization. In 1998 42 percent of the population was male, but by 2011 the bulls—which carry more ivory—made up only 32 percent, STE explained. “Ten of the fifty elephant groups were effectively wiped out, with no known breeding females left, while thirteen had no breeding female over the age of 25.”
Elephant Memory Banks Destroyed
“This represents the destruction of elephant memory banks, and when these are destroyed, the survival of those remaining is lowered,” writes Iain Douglas-Hamilton, founder of Save the Elephants, and co-author of the PLOS One paper. “With the loss of numerous well known and stable family groups came increased numbers of orphans. Those who were under the age of two when they lost their mother all died. Older survivors adopted a number of different strategies, either remaining solitary, teaming up with other orphans, or joining another group.”
At first, the elephants of Samburu responded to the poaching pressure by increasing their reproductive efforts and producing more babies, according to the study. But now the soaring price of ivory is overwhelming any strategy to compensate for the killing.
So what will it mean for Africa’s last wild elephants if so many of the older animals are removed? What exactly do elephants know and what will happen if they forget the lessons handed down across countless generations?
A Voice for Elephants interviewed Iain Douglas-Hamilton about the research:
David Braun: How long have you been studying elephants in Africa, and how did you come to research the paper you published today?
Iain Douglas-Hamilton: I’ve been studying elephants for 43 years. I started in December 1965. The elephant population we used for this research has been studied for 14 years, since 1997. Most of the work was done by George Wittemyer, the Colorado State University professor who is the lead author on this paper. We have a great team going, with local people and people from world-class universities who come and work on this project.
What are your key findings?
It’s really about the intimate population dynamics—birth, death, movements—and how that’s changed over time. And in particular how that’s changed in relation to this recent ivory surge.
This population was one of the most sensitive barometers to social change, and it registered change before most of the other groups did. This was not because these elephants have been more heavily poached than others, but because this group is very sensitively observed. The method we use is individual recognition of a known sample of elephants, and so we pick up on absolute numbers of deaths and births.
We found that everything started tipping from 2008. Before that we had a steady increase in population. These elephants had already been through a severe killing spree in the 1970s and 80s, and they were recovering. Our studies started 14 years ago, and we noticed a gentle increase in elephant population year after year right up until 2008, and then there was a switch. It was triggered by a one-off drought, in 2009, accompanied by record levels of illegal killing in 2010 and 2011.
The interesting thing is that we warned over a year ago, in the early part of 2011, that if this could happen to a well-monitored relatively well-protected elephant population, it could be what was going to happen elsewhere in Africa. And that prediction was quite well borne out.
It’s ironic that the elephants in Samburu are peaceful and trusting. They’re one of the best spectacles of elephants anywhere in Africa. You can still approach them; they don’t run away from you, they don’t run away from the car. The reason is because inside the protected area of Samburu they’re completely safe. Samburu has a very, very low level of illegal killing. But they go outside into danger zones, and that’s where the poachers are waiting for them for their ivory. They leave the safety of the park. They get wounded if they are not killed, and they run back into the park. So it’s the very nature of the elephant to quest outside for good food that gets them into trouble.
Actually, the reserve as it is could never support the number of elephants if you put a fence around it. So the wonderful spectacle of elephants that you see when you come to Samburu is reliant on a much wider dispersal area. And that’s where they get into trouble.
We’ve had huge success in getting local communities on side in most of the areas. But there is one area that has become a bad killing zone, and that is an area which is also disputed between human beings as to who should be the dominant group in charge. You have a certain amount of ethnic conflict there, and it’s into this maelstrom that the elephants wander.
The Samburu study gives chapter and verse of what it means to be poached, which is usually lacking in all the other places where there is poaching that you have been reading about. We just don’t have the same detail for Tsavo or central Africa or any of the other sites where poaching is now at high levels.
You have found a steep decline in the number of older individuals?
Absolutely. There has been a decline in the big mature bulls and a higher rate of mortality. Higher mortality does not necessarily mean an overall decline in population, but in the case of the really large elephants, yes, there has been a decline in numbers. There has been a relative decline over all 14 years of our study, as the big males were selectively targeted, but it didn’t have an effect on the overall population size; it just had an effect on that population class.
You talk about loss of memory banks. What exactly do elephants know and how do they transmit their knowledge?
It’s mainly the female memory. Females are much better studied than the males because they’re the leaders in a family. They give a signal of when and where to move, or where to avoid, which is equally important.
Studies elsewhere in Africa show that families which lose large numbers of matriarchs do much less successfully in later life. They have a low survival rate. In the time of drought, for example, the really smart and experienced matriarchs may take their families to a completely different place, only because they’re experienced. Maybe they remember their mothers took them to a place like that when they were young. That means sometimes that they have to take a counterintuitive decision. Like maybe in a really drought-stricken area you’d have to go deeper into the worst area to get through to the other side. That happened in Tarangire, as reported in a study which showed that the really old matriarchs knew what to do. Young elephants tend to have a higher rate of survival if they have good leadership.
Another factor in elephant survival is their relationships with people. An old matriarch will have a lot of experience with people and know when and where to avoid people and when to be calm with people. We see it all the time in Samburu because we have a safe haven in the core of the reserve, and in that area the matriarchs will decide how long to stay, when to move out, and where it is safe to move out.
You can see very clearly that there are some families that are much better survivors than others. That’s something that George Wittemyer noticed. He noticed some really interesting new stuff like the size of an elephant’s range and the positioning of the range is very much related to the dominance between families. So if you’re a dominant family that means you’ve got really big old leaders who can compete with other families. It means that they can go to the best areas, stay there the longest, and that they have to walk less distance to get what they need out of life. That again is all a subtle interplay with memory and leadership and dominance.
With the loss of memory banks, what are the breakdown effects on the young survivors? What can’t they do when there are no wise elders to teach them?
If you lose your mother, if you’re under five years old, you’ve got a very high percentage chance of dying. That’s simply because she’s not there to look after you. We’re doing a study right now on the broader breakdown effect on elephant society. We’ve had this excessive mortality of large females. There are families which have lost all the breeding females. They are left with young orphans. We know that the orphans have much lower prospects of survival because they’re more vulnerable to predation, being lost, and taking the wrong decisions. There are a host of things that will have an effect on how well they feed, how well they choose safe places.
Is there also a breakdown in how elephants relate to humans, specifically with regard to increasing the prospects of them coming into lethal conflict with people outside safe areas?
Samburu is an area surrounded by pastoral people, so there is relatively little direct crop-raiding going on there. By and large the pastoralists have been remarkably tolerant of wildlife. Samburu and Maasai, because of their culture, have been able to live alongside wildlife, and wildlife has been able to thrive. If you think of it, Serengeti, Tarangire, Amboselli, Maasai Mara, Samburu are all beautiful wildlife areas inhabited by Maa-speaking people, and those people have evolved and adapted their cultures so that they are now playing an important role in the ecotourism industry. I think that this is the great hope, that basically their culture which has at least tolerated wildlife, can now begin to favor wildlife. There are some absolutely outstanding wildlife guides, rangers, wardens, and I’m hoping there are going to be scientists who come from that background. One of the things that encourages me about Kenya is that there is a huge increase in educated people in the wildlife field whom you can rely upon to do their best.
The real problem is that however good things are, when you reach a certain point when the incentive, particularly for rhinos and elephants, is so high, it’s difficult to see how you are going to cope with existing resources. You’re not going to cope. You can increase the boots and guns on the ground massively, you can train more people, you can move closer and closer to guerrilla warfare against the poachers, but unless you can reduce the incentive, which is the price of ivory, and that means reducing the demand at the ultimate consumer end, it’s very difficult to see how we are going to win.
Is there any hope that this situation can be resolved before elephants are extirpated in the wilderness?
I think our best strategy is sharing information with the consumers. They don’t know what they’re doing. That’s my belief, and it’s backed up with a lot of what we read in the papers. I want to go all out and share our awareness with the Far East, and invite some of them to come and work with us, and I want to promote bilateral understanding, talk to the fashion industry, and do whatever it takes to let them share our exaltation in the beauty of nature and also our dismay at the destruction of it.
It happened in Europe, America, and Japan—important places where the appetite for ivory decreased in the last 20 years. The only question is do we have 20 years to persuade the new affluent middle classes that are buying ivory. The answer is we don’t have that much time. We have to make this change happen a lot faster.
On the hopeful side, communications have improved so much. First of all, there are more eyes and ears on the ground, so poaching does get noticed. And it’s going to be relayed across the globe. That’s why I am happy that the “Blood Ivory/Ivory Worship” article came out in National Geographic. It was very well done.
What we are trying to do now is to create a coalition of scientists, institutions, and governments to take international action to lower the demand for ivory. Everyone can agree that demand exceeds supply, so demand should be reduced. Even if you are a hunter or someone who thinks we should allow legal trade in ivory, you can agree that demand exceeds supply. If we all agree that this is the case, then there is hope that we can make some progress to lower demand.
More from National Geographic:
Blood Ivory/Ivory Worship
Thousands of elephants die each year so that their tusks can be carved into religious objects. Can the slaughter be stopped? By Bryan Christy in National Geographic Magazine.
Family Ties: The Elephants of Samburu. By David Quammen in National Geographic Magazine.
Elephants of Samburu Video
Photographer Michael Nichols follows elephants as they eat, sleep, and play.
Africa’s Elephants: Can They Survive? By Oria Douglas-Hamilton in National Geographic Magazine.
Saluting Changila. By Oria Douglas-Hamilton in A Voice for Elephants.
Stop Stimulating the Ivory Trade; Just Stop Trade. By Mary Rice in A Voice for Elephants.
Comparative Demography of an At-Risk African Elephant Population (Plos One), by George Wittemyer, David Daballen, and Iain Douglas-Hamilton.
Abstract: Knowledge of population processes across various ecological and management settings offers important insights for species conservation and life history. In regard to its ecological role, charisma and threats from human impacts, African elephants are of high conservation concern and, as a result, are the focus of numerous studies across various contexts. Here, demographic data from an individually based study of 934 African elephants in Samburu, Kenya were summarized, providing detailed inspection of the population processes experienced by the population over a fourteen year period (including the repercussions of recent increases in illegal killing). These data were compared with those from populations inhabiting a spectrum of xeric to mesic ecosystems with variable human impacts. In relation to variability in climate and human impacts (causing up to 50% of recorded deaths among adults), annual mortality in Samburu fluctuated between 1 and 14% and, unrelatedly, natality between 2 and 14% driving annual population increases and decreases. Survivorship in Samburu was significantly lower than other populations with age-specific data even during periods of low illegal killing by humans, resulting in relatively low life expectancy of males (18.9 years) and females (21.8 years). Fecundity (primiparous age and inter-calf interval) were similar to those reported in other human impacted or recovering populations, and significantly greater than that of comparable stable populations. This suggests reproductive effort of African savanna elephants increases in relation to increased mortality (and resulting ecological ramifications) as predicted by life history theory. Further comparison across populations indicated that elongated inter-calf intervals and older ages of reproductive onset were related to age structure and density, and likely influenced by ecological conditions. This study provides detailed empirical data on elephant population dynamics strongly influenced by human impacts (laying the foundation for modeling approaches), supporting predictions of evolutionary theory regarding demographic responses to ecological processes.