Top Predators Impact Entire Ecosystems
Declines at the top of the food chain over the last several thousand years have been well documented. Now researchers have found that these declines in predators and large herbivores may have profound impacts on ecosystem function, resilience, and health throughout the world.
In a paper published in the July 15 issue of the journal Science, an international team of 24 researchers presented evidence highlighting the reverberating — and often unexpected — effects caused by the loss of these “apex consumers,” not only on immediate prey species, but also on the dynamics of fire, disease, vegetation growth, and soil and water quality.
For example, research by ESPM associate professor Justin Brashares linked the decline of apex predators such as lions to the increase in baboon populations in sub-Saharan Africa. As baboon numbers swelled, there was an increase of intestinal parasite transmission from baboons to humans.
“This is the first paper to bring together studies that present strong empirical evidence of what naturalists and ecologists have long suspected,” said Brashares, who with Mary Power, UC Berkeley professor of integrative biology, worked closely on the study with lead author James Estes, adjunct professor of ecology and evolutionary biology at UC Santa Cruz.
Based on their findings, the researchers recommend that the health of apex predators should be taken into account in conservation and management decisions.