Humans are super predators and Earth is bearing the burden of our dominance
Humans have evolved into super predators and our planet is bearing the burden of our predatory dominance, researchers have suggested in a new study that examines the unique ecology of human predators.
Published in journal Science, the study is an attempt to look at widespread wildlife extinctions, shrinking fish sizes and disruptions to global food chains from a new angle and humans as super predators are at the center of all this.
A team led by Dr. Chris Darimont, the Hakai-Raincoast professor of geography at the University of Victoria, peg humans as efficient killers and this ability combined with our global economic systems and resource management that give priority to short-term benefits have evolved humans into super predators that is impacting the planet to a great extent.
Some other factors including geographic expansion, exploitation of naïve prey, symbioses with dogs, and rapid population growth, have also helped humans leave a profound impacts on the planet including widespread extinction and restructuring of food webs and ecosystems—in terrestrial and marine systems.
According to an estimate put forward by the team, there is a huge variation in exploitation rates between hunters and terrestrial predators. Humans exploit adult fish populations at a rate that is 14 times that of other marine predators. Further, our kill rate of large land carnivores such as bears, wolves and lions is nine times the rate that these predatory animals kill each other in the wild.
Humanity also departs fundamentally from predation in nature by targeting adult quarry. “Whereas predators primarily target the juveniles or ‘reproductive interest’ of populations, humans draw down the ‘reproductive capital’ by exploiting adult prey,” says co-author Dr. Tom Reimchen, biology professor at UVic. Reimchen originally formulated these ideas during long-term research on freshwater fish and their predators at a remote lake on Haida Gwaii, an archipelago on the northern coast of British Columbia.
The data set includes wildlife, tropical meat and fisheries systems from every continent and ocean, except Antarctica. The authors conclude with an urgent call to reconsider the concept of “sustainable exploitation” in wildlife and fisheries management. A truly sustainable model, they argue, would mean cultivating cultural, economic and institutional change that places limits on human activities to more closely follow the behaviour of natural predators.
You can read the full text here.