Scientists who analysed the causes of death in elephant populations across Africa have found that rates of illegal killing reached up to 7% between 2010 to 2012.
And there was more poaching when the price of ivory increased following confiscation by police of hauls of illegal ivory.
The covert nature of illegal elephant killings makes it difficult to quantify the contribution of poaching to elephant population declines.
To develop repeatable, data-based estimates of local and continental elephant poaching rates, George Wittemyer at Colorado State University and colleagues examined demographic data and analysed cause of death for elephant populations across Africa.
“Illegal harvest for commercial trade in ivory has recently surged, coinciding with increases in illegal ivory seizures and black market ivory prices,” the researchers write
“As a result, the species declined over the past four years, during which tens of thousands of elephants have been killed annually across the continent.”
The authors began by investigating elephant poaching rates at a local scale, surveying elephant carcasses in Kenya’s Samburu National Reserve to distinguish between illegal and natural
causes of mortality.
Locally, poaching rates increased with increases in the local market price for ivory and seizures of illegally harvested ivory throughout Kenya and the world.
To estimate poaching at a continental scale, the authors extended their initial analysis by combining demographic data for the species with carcass survey data covering African elephant populations at 45 sites across Africa.
At the continental scale, African elephant populations suffered illegal killing rates of approximately 7% each year from 2010 to 2012, and preliminary data from 2013 indicated a killing rate higher than 5%.
Illegal killings drive declines in elephant populations that endanger the species’ survival, and the accurate estimate of population dynamics driven by poaching may help inform conservation measures and management actions.
The finds of the study are published in the journal PNAS.
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