Of all conflicts between humans and large carnivores, the most challenging involves the African lion. Since no major wildlife African ecosystem is completely fenced, lions attack thousands of livestock throughout the continent each year and lions kill over a hundred people a year in southern Tanzania and northern Mozambique. Of the less than 50,000 lions still in Africa, about a quarter are found in four large well-protected ecosystems (Serengeti, Selous, Okavango/Chobe, Kruger); the rest are exposed to varying degrees of human contact and may not survive until the 22nd century without intensive management.
Recent studies of human-lion conflict in eastern and southern Africa have shown three consistent patterns:
- Humans directly retaliate against lions for killing livestock.
- Traditional practices of livestock husbandry reduce but do not eliminate the risk of lion attacks.
- Far fewer livestock are lost to lions than to disease or drought.
While these findings suggest that human-lion conflict might be managed to produce an acceptable level of risk to local communities, it is clearly urgent to identify effective low-cost mitigation strategies. Highly invasive responses such as erecting fences are neither feasible (e.g. the Selous is the size of Switzerland) nor ecologically acceptable (e.g. trapping migratory ungulates inside fenced reserves) and translocating people or problem lions would be politically unacceptable.
For the past five years, we have conducted intensive field research on the ecology of cattle-killing in two parts of Tanzania:
- The Tarangire/Manyara ecosystem is typical of many migratory systems where only a core dry season refuge was gazetted as a National Park, while the wet season dispersal area has become increasingly occupied by agriculturalists and pastoralist Maasai for more than 20 years.
- The Ngorongoro Conservation Area (NCA) was the world’s first multiple land-use area, where pastoralist Maasai were allowed to remain inside the equivalent of a national park, provided that they retained their traditional way of life. Livestock predation is a way of life in the NCA, and the Maasai rely entirely on traditional husbandry practices.
Bernard Kissui’s research in the greater Tarangire ecosystem has shown that lions, leopards and spotted hyenas are the three major predators on livestock, but the lion is most vulnerable to retaliatory killing. Lions are exceptionally vulnerable to retributive killing by pastoralists compared to hyenas and leopards for several reasons. First, lions are more likely to defend a livestock carcass against humans, exposing them to frequent confrontations which they inevitably lose. In contrast, hyenas are shy of people, moving well beyond the reach of humans after a livestock attack, whereas leopards can successfully hide themselves. Second, lions engender more human resentment by mostly killing cattle, which have more value to pastoralists than the sheep and goats typically attacked by hyenas and leopards. Third, in contrast to the nocturnal attacks of leopards and hyenas, most lion attacks occur during the day, when people are armed and prepared to defend their stock, and searching for predators is far easier during the day. Fourth, Maasai culture contributes to the vulnerability of lions through the practice of Ala-mayo where a young warrior can prove his courage by killing a lion (see below). Cattle-killing provides a legal opportunity to engage in a lion hunt.
Ngorongoro Conservation Area
Dennis Ikanda’s research in the NCA has revealed two factors that greatly increase the risk of lion attacks on Maasai grazing cattle (Figure 2). Lions can apparently distinguish warriors from children and monitor how well herds are tended, because attack rates were more than five times higher when cattle herds were tended solely by children rather than by warriors (Morani) and nearly four times higher when more than 150 cattle were tended by each herder. In contrast to Tarangire, the Maasai in the NCA do not strictly kill lions in retaliation for cattle depredation. Although there is a broad correlation across the major regions of the NCA in the number of lions killed vs. cattle killed by lions, far more lions were killed in one area (known locally as Angata Kiti) compared to cattle predations (Figure 3a). This is the same area that is most commonly visited by nomadic lions from the Serengeti following the annual wildebeest migration each wet season (Figure 3b), and most lions are killed during the wet season in Angata Kiti whereas there is no seasonal pattern to livestock depredation. Interviews with Maasai revealed that young Morani would come to Angata Kiti each year just for the opportunity to participate in an Ala-mayo, or ritual lion hunt.
Mitigation strategies for Maasai-lion conflict
Results from the NCA project suggest that the incidence of lion attacks on cattle could be greatly reduced by simply encouraging the Maasai to send their children to school (consistent with Tanzanian Government policy of attaining universal literacy) and to break their herds into smaller units so as to maintain a more favourable number of livestock per herder (also consistent with Tanzanian Government policy of reducing the environmental impact from overgrazing). Although lions are less likely to attack the bomas at night when compared to other predators, nocturnal lion attacks are sufficiently common to fuel widespread resentment by the Maasai. Bernard Kissui has found that many of the bomas around Tarangire are so flimsy that a nocturnal predator merely has to provoke a stampede to get the livestock to break out of their kraals, whereupon they can be easily caught. Kissui has successfully convinced 60 Maasai families to reinforce their bomas with chain-link fencing, which has so far prevented any nocturnal losses to predation. Most importantly, each family paid at least half the costs for the fencing themselves—in most cases by selling off a large cow and using the money to buy the fencing and a small calf—effectively maintaining a constant herd size. More and more families are expressing interest in the program, but it remains to be seen whether the strategy can be expanded to cover the 12,000 bomas in the Maasai Steppe.
Figure 1 Relationship between the number of lions, hyenas and leopards killed by pastoralists in each village and the associated number of attack events by each species. Dotted circles indicate two villages that reported frequent use of poison against hyenas.
Figure 2 Monthly risk of depredation on grazing herds of cattle in the NCA. (A) Herds tended solely by herd boys suffered higher rates of depredation than herds tended solely by Moranis (p = 0.05); vertical bars indicate standard errors. (B) Risk of attack increased with the average number of cattle tended per herdsman (p = 0.0006).
Figure 3 Spatial pattern of lion attacks and lion sightings in the NCA. (A) Percentage of livestock lost to lions (hatched bars) vs. lions killed per Maasai (black line) across four broad geographical areas in the NCA. (B) Lion sightings by the Serengeti lion project 1984-2004 inside Serengeti National Park (grey) and in the NCA (black), as well as of Ngorongoro Crater lions (also black; all of which were in/near the Crater) during the Wet and Dry seasons. The northern-most part of the NCA includes Angata Kiti.
- The ecology of man-eating lions in Tanzania
- Lion attacks on humans in Tanzania
- Livestock predation by lions, leopards, spotted hyenas, and their vulnerability to retaliatory killing in the Maasai steppe, Tanzania
- Nature & Faune Vol. 21, Edition 2 English
- Nature & Faune Vol. 21, Edition 2 Francais
- Persistence and local extinction of lion prides in the Ngorongoro Crater, Tanzania
- Rational fear
- Ritual vs. retaliatory killing of African lions in the Ngorongoro Conservation Area, Tanzania