Scientists find elephant memories may hold key to survival
Tuesday 12 August 2008
A recent study by the Wildlife Conservation Society and ZSL suggests that old female elephants — and perhaps their memories of distant, life-sustaining sources of food and water — may be the key to survival during the worst of times.
In particular, experienced elephant matriarchs seem to give their family groups an edge in the struggle for survival in periods of famine and drought, according to a recently published paper in ‘The Royal Society’s Biology Letters’.
Dr Nathalie Pettorelli, ZSL researcher and co-author, said, ‘Climate change is expected to lead to a higher occurrence of severe drought in Africa and our study suggests that such extreme climatic events may act as a selection force on animal populations.
'As animals battle to cope certain individuals, such as these grand dames of the elephant kingdom, might become increasingly important.’
‘Understanding how elephants and other animal populations react to droughts will be a central component of wildlife management and conservation,’ commented Wildlife Conservation Society researcher Dr. Charles Foley, lead author of the study.
‘Our findings seem to support the hypothesis that older females with knowledge of distant resources become crucial to the survival of herds during periods of extreme climatic events.’
The study examines patterns of calf mortality during the drought of 1993 in Tanzania’s Tarangire National Park, the most severe drought in that region in the past 35 years. During a nine-month period of that year, sixteen out of 81 elephant calves in the three groups studied died, a mortality rate of 20 percent. The normal mortality rate of calves during non-drought years is a mere two percent.
When compared with other data, researchers noted correlations in calf survivorship with the movements of the groups and, in particular, the ages of the female members within those groups.