Picture a northern Pacific archipelago: forested islets and sandstone beaches, blue-gray water lapping against a rocky shore. A wave crashes, a gull caws, a raccoon ambles around in the intertidal zone, clambering over slick rocks in search of something to eat.
Now inject terror into the scene: the sound of a hungry dog barking. Suddenly, the landscape is transformed.
This is what Justin Suraci, an ecologist at the University of Victoria, found after spending several years on the Gulf Islands in British Columbia, trying to terrorize some small mammals. It was a silly-sounding project — and Suraci will admit he looked pretty silly doing it — with a sobering result.
Terror turned out to play a critical role in balancing the ecosystem, Suraci said in a study published Wednesday in the journal Nature Communications. It’s the driving force of an emotional drama that plays out on the Gulf Islands and every other landscape in the world without humans ever noticing.
Fear of large predators — not just the predators themselves but the larger, all-encompassing dread of their presence — keeps smaller “mesopredators” in check. It means that those animals spend less time eating and more time worrying about getting eaten. This in turn allows their even smaller prey to flourish, maintaining an ecological harmony that has been honed for millennia. Read more...