January 22, 2009

Elephant poaching: Long negative effects

A U.S. study shows the negative effects of African elephant poaching persist for decades after the killings.

Kathleen Gobush, a research ecologist at the National Oceanic and Atmospheric Administration who led the study, said African elephants rely heavily on matriarchs to lead groups and keep families together. Before the 1989 ban on ivory trade, nearly 75 percent of all elephants in Tanzania's Mikumi National Park were killed, many of them females with large tusks.

A lot of these females lost their sisters and mothers, and were left living a solitary existence, added Sam Wasser, director of the Center for Conservation Biology at the University of Washington. So the question became, what are the long-term impacts on the genetic relatedness of groups?

The scientists tracked more than 100 groups of elephants, assessing the effects of poaching on group size, relatedness and social bonding.

They found the elephants formed unusually small groups, with nearly a third of the females living alone. But some elephants forged new bonds with unrelated groups after their own kin had perished.

Elephants are "¦ extremely social, and there's a tremendous amount of group integrity and competitive ability, Wasser said. It's been nearly 20 years since the ivory ban and there are still incredibly persistent impacts of illegal culling on these populations.

The research appears in the online edition of the journal Molecular Ecology and will soon appear in print.