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Building better bomas

National Geographic Big Cats Initiative (BCI) scientist Stuart Pimm ventures into East Africa to study bomas, the traditional shelters constructed to corral livestock. He visits two BCI grantees working with local herders to fortify bomas with wire and spiny plants in so-called ”living fences.” The hope is that if farm animals can be protected their owners will have...

National Geographic Big Cats Initiative (BCI) scientist Stuart Pimm ventures into East Africa to study bomas, the traditional shelters constructed to corral livestock. He visits two BCI grantees working with local herders to fortify bomas with wire and spiny plants in so-called ”living fences.” The hope is that if farm animals can be protected their owners will have no incentive to poison or otherwise persecute lions and leopards that prowl through cattle ranches near wildlife preserves at night.

This is only one way that the National Geographic Big Cats Initiative is trying to reduce the growing conflict between humans and big cats in Africa.

By Stuart Pimm

East of Tarangire National Park, Tanzania–Anne Kent Taylor is unmistakeable. It’s not the hat, the red blouse and scarf, and Maasai jewellery, but the way she greets everyone in the Mara. First comes a vigorous wave and then enthusiastic Swahili. To me, she talks in English with an accent that identifies her heritage (her father was a colonel in the British Army)–and upbringing (she was born in Ethiopia, grew up in Kenya).

Anne is a new National Geographic grantee. [Read her recent field reports from the Maasai Mara about how she is using her National Geographic Big Cats Initiative grant.] She received her money from the BCI a few weeks ago, so I’m in the Mara, in southwestern Kenya, to learn from her.


Photo of Anne Kent Taylor with an unidentified assistant (left) by Stuart Pimm

Anne protests: “I’m not a scientist. I have no training…” I interrupt these protestations–and continue to do so with ever more vigor over our next few days together. Scientific credentials be damned, Anne is a very effective conservation professional with a deep and effective understanding of what it takes to save nature. When I write my conservation textbook, she’ll be in it.


Photo of wire fencing delivery by Stuart Pimm


Photo of a better boma by Stuart Pimm 

Anne’s solution is to build a better boma. A boma? The Oxford English Dictionary attributes the first English use of the word to Henry Stanley–he of “Dr. Livingstone, I presume,” fame. One gathers thorny bushes to create a circle around one’s camp. That way the lions don’t eat you. In this part of Africa, that is a distinct possibility if you sleep out at night.

(Tents seem to work, too. But listening to heavy breathing a few feet away on the other side of flimsy nylon fabric always has me worried. One night, a lion with a high IQ may change the balance of terror forever.)

Certainly, lions are not stupid. One strategy is to terrify the cattle inside a boma until they stampede out of it–to where your sister lions are waiting for an easy snack. Well, at least until the males come along and push them off the kill.


Photo by Stuart Pimm

For the Maasai, cattle are wealth and they don’t like the idea of losing it. Cattle are an essential requirement for getting a bride. So if I had just lost most of my wealth and any chance of marrying, I’d probably take it out on the lions too.

Spears will do the trick, if you have sufficient pluck, but given the carcass of a dead cow and readily available and very deadly insecticides, sprinkling lethal powder on the remains will also do the job.

And it will kill anything else that comes to the kill too.

Stopping the misuse of very nasty poisons in East Africa is what Big Cats grantee Paula Kahumbu is trying to do. But that’s a story I will tell later.

Anne’s point is simple: “If there are no dead cattle, there’s nothing onto which to put poison.” Anne wants to make sure that lions, leopards, hyenas, and other predators can’t get into the bomas.

So with her team, Anne buys and delivers chain link fence. She charges the boma owners for half the fencing and they have to install it.

Click on the image to find out more about the Big Cats Intiative. Photo compilation courtesy of Beverly and Dereck Joubert

Three hundred and fifty kilometres (225 miles) to the southeast, Dr. Laly Lichtenfeld is also building better bomas. She, too, is a new Big Cats Initiative grantee. She’s trying a different technology, but the basic ideas are very similar.

Laly, husband Charles Trout, and the rest of her team also use chain link fence. Like Anne, they work closely with local communities, driving around working out where to deliver more chain link.

Laly has added a traditional twist. Commiphora africana–and I know no common name for it –has impressive thorns. In the dry season, when it looks simply like a dead twig, Laly’s team cuts them and sticks them in the ground in neat rows around the boma.

She’s the first to admit they look really silly. A line of thin dead sticks wouldn’t keep anything out. Although they look dead, when it rains, they spring to life. Trellised into the chain link fence, there will soon be a living wall of very spiny bush to make an impenetrable boma.

There’s something in all this that makes me pause. Why is important to protect lions outside of national parks? One answer is that lions move around a lot.

Each lion takes up an average of about ten square kilometres, so a pride of two males, four females, and their cubs, may occupy ten times that–about 40 square miles. That’s a rough guess, based on average densities in South Africa, but it gives a good idea of how much space a pride needs.

Lions wander and, when they do, they can get into trouble.

The more complicated answer is that Africa’s national parks may be large, but they aren’t large enough. Were it not for Anne and Laly’s efforts to save lions outside of protected areas, the lion populations inside might be too small to survive.

Video of Laly Lichtenfeld and Anne Kent Taylor in the field by Stuart Pimm 

What Anne and Laly are both doing is to make up for the inadequate design of parks that were designed to the surrounding areas in order to be ecologically viable. That’s a tall order. Their success–so dependent on support from the National Geographic Big Cats Initiative–is why this work is so very important to conserving lions and, very generally, how to manage biodiversity.

And that point will be the subject of my next blog, for Anne and Laly do very much more than build bomas. Why they do so much–and why it’s important for conservation, needs more words than I have here.

Incidentally, Anne and Laly have never met. I promised them both that I’ll help set up the first meeting of the Better Boma Builders.

Stuart Pimm.jpg

Professor Stuart L. Pimm is a conservation biologist at Duke University, North Carolina. A former member of the National Geographic Committee for Research and Exploration, Pimm is the author of dozens of books and research papers, including the book “The World According to Pimm: A Scientist Audits the Earth.”


 Earlier blog posts by Stuart Pimm>>



Anne Kent Taylor’s July/August 2010 field report:

NGS In the Field.jpg

Part One: Saving Africa’s last wild lions by fencing them out (July 23, 2010)

Part Two: Fences make predators more tolerable to Kenya farmers (July 25, 2010)

Part Three: Good fences make good neighbors of Kenya’s lions and herders (August 16, 2010)


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Meet the Author

Stuart Pimm
Stuart Pimm is the Doris Duke Chair of Conservation Ecology at the Nicholas School of the Environment at Duke University. He is a world leader in the study of present day extinctions and what we can do to prevent them. Pimm received his BSc degree from Oxford University in 1971 and his Ph.D from New Mexico State University in 1974. Pimm is the author of nearly 300 scientific papers and four books. He is one of the most highly cited environmental scientists. Pimm wrote the highly acclaimed assessment of the human impact to the planet: The World According to Pimm: a Scientist Audits the Earth in 2001. His commitment to the interface between science and policy has led to his testimony to both House and Senate Committees on the re-authorization of the Endangered Species Act. He has served on National Geographic’s Committee for Research and Exploration and currently works with their Big Cats Initiative. In addition to his studies in Africa, Pimm has worked in the wet forests of Colombia, Ecuador and Brazil for decades and is a long-term collaborator of the forest fragmentation project north of Manaus, Brazil. Pimm directs SavingSpecies, a 501c3 non-profit that uses funds for carbon emissions offsets to fund local conservation groups to restore degraded lands in areas of exceptional tropical biodiversity. His international honours include the Tyler Prize for Environmental Achievement (2010), the Dr. A.H. Heineken Prize for Environmental Sciences from the Royal Netherlands Academy of Arts and Sciences (2006).