Elephant population trends in Kenya: 1977–1981

Abstract

Summary Population estimates and distributions of the African elephant (Loxodonta africana) in the entire Kenya rangelands was obtained using light aircraft during the period 1977–1981. The population of elephants for the whole of Kenya was 75,300 ± 5000 in 1977, 55,300 ± 5000 in 1978 and 51,200 ± 5000 in 1980–1981. The ratio of live to dead elephants decreased from 4‐0: 1 in 1977 to 2‐0:1 in 1978 and 1.27: 1 in 1980–1981; an indication of rapid rise in elephant mortality. All except 7500 ± 2500 of these elephants were on the rangelands (500,000 km2), especially in the Hola, Ijara, Tsavo, Mtito Andei, Jipe and Lamu eco‐units. Their numbers were also relatively high in Meru, Laikipia and Mara eco‐units. The 7500 ± 2500 elephants occurring outside the rangelands were mainly found in the Aberdare and the Mt Kenya National Parks, Mt Elgon and the Mau Forest. Although the rapid downward trend in elephant numbers slowed down between 1978 and 1980–1981, there is still an urgent need for stringent conservation measures to be instituted. RÉSUMEÉ Des estimations de population et les distributions de l'éléphant africain (Loxodonta africana) sur l'entièreté du territoire du Kenya furent obtenues par l'utilisation d'un avion léger durant la période 1977–1981. La population d'éléphants pour le Kenya entier était de 75,300 ± 5000 en 1977, 55,300 ± 5000 en 1978 et 51,200 ± 5000 en 1980–1981. Le rapport éléphants vivants/éléphants morts décroǐt de 4.0:1 en 1977 à 2.0:1 en 1978 et àl.27:l en 1980–1981, ce qui indique une augmentation rapide de la mortalitè. A part 7500 ± 2500 éléphants, tous étaient dans les rangelands (500,000 km2), spécialement dans les régions de Hola, Ijara, Tsavo, Mtito Andei, Jipe et Lamu. Leur nombre était aussi relativement élevé dans les unités écologiques de Meru, Laikipia et Mara. Les 7500 ± 2500 éléphants présents en dehors des rangelands furent observés principalement dans les Pares Nationaux d'Aberdare et du Mt Kenya, sur le Mont Elgon et dans la Forét de Mau. Malgré que la tendance dégressive rapide du nombre d'éléphants se soit ralentie entre 1978 et 1980–1981, il y a toujours un besoin urgent d'instituer des mesures de conservation drastiques.

An assessment of long‐term food habits of Tsavo elephants based on stable carbon and nitrogen isotope ratios of bone collagen

“…More recent density estimates (Ottichilo, et al, 1987), show a striking decline for Kenya from approximately 75,000 in 1977 to 51,000 in 1981, suggesting either high mortality or reduced recruitment. The reduction was probably due to drought from 1974 to 1976 and to intense poaching from 1976 to 1978 (Ottichilo, 1987). The reduction was probably due to drought from 1974 to 1976 and to intense poaching from 1976 to 1978 (Ottichilo, 1987).…”

“…The distributions, migratory patterns and densities of elephants are less clear (Tyrrell, 1985), although historical reconstructions suggest that resident populations existed in the area which is now the Tsavo National Park perhaps since the late 1800s. More recent density estimates (Ottichilo, et al, 1987), show a striking decline for Kenya from approximately 75,000 in 1977 to 51,000 in 1981, suggesting either high mortality or reduced recruitment. In Tsavo itself, a severe drought in 1970-1971 led to 6000 deaths; and Ottichilo (1986) showed a reduction from 35,000 in 1974 to about 14,000 in 1980.…”

Illegal tusk harvest and the decline of tusk size in the African elephant

“…Illegal ivory harvesting caused unprecedented decline in elephant populations across the continent in the late 1970s and early 1980s; some protected areas in East Africa lost as much as 50–90% of their elephant numbers (Eltringham and Malpas ; Douglas‐Hamilton ; Ottichilo et al. ; Barnes and Kapela ; Prins et al. ).…”

“…Efforts to determine the consequences of illegal harvesting on African elephants have focused on its effects on their population sizes and life history (Barnes and Kapela 1991;Prins et al 1994;Gobush et al 2008;Bouche et al 2011). Illegal ivory harvesting caused unprecedented decline in elephant populations across the continent in the late 1970s and early 1980s; some protected areas in East Africa lost as much as 50-90% of their elephant numbers (Eltringham and Malpas 1980;Douglas-Hamilton 1987;Ottichilo et al 1987;Barnes and Kapela 1991;Prins et al 1994). Illegal ivory harvesting caused changes in age and sex structure leading to reduction or elimination of older animals; an effect more severe in males compared to females (e.g., Poole 1989;Poole and Thomsen 1989;Barnes and Kapela 1991).…”

Evaluating support for rangeland‐restoration practices by rural Somalis: an unlikely win‐win for local livelihoods and hirola antelope?

“…Currently, and although elephant populations in eastern Kenya seem to be recovering, they are far below the ca. 5000 individuals that inhabited this region in the 1970s (Ottichilo, Kufwafwa & Stelfox, 1987;Butynski, 2000;Thouless et al, 2016). Indeed, in a recent study on hirola movement and habitat selection, tree encroachment was the ultimate driver of hirola habitat availability, more so than access to water or proximity to people (Ali et al, 2017).…”