Medical Research Council - London Institute of Medical Sciences

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Rodentation Risk
10 May 2014

Rodentation Risk

Scientists have found that the loss of big mammals, like elephants, giraffe and zebra, can lead to an increase in risk of human disease. Hmm… how does that work? It’s because declines in large wildlife mean that rodent populations explode, along with their frisky free riders – fleas (pictured). Genetic analyses of the rodents’ fleas revealed that they were carrying a legion of the particularly harmful Bartonella bacteria, which can cause heart infection, liver damage and memory loss. When large animals were excluded, using powerful electric fences, from study plots in East Africa the number of both rodents and Bartonella-carrying fleas in these zones doubled. This proliferation of rodents triggered by the loss of larger animals, known as rodentation, has been observed around the world. And presumably makes for a very disappointing safari – as a large, red sun sinks behind the African savannah, a herd of the majestic elephant shrew emerge…

Written by Nick Kennedy

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