Friday, August 21, 2015

The unique ecology of human predators

Date:
August 20, 2015
Source:
University of Victoria
Summary:
Research reveals new insight behind widespread wildlife extinctions, shrinking fish sizes, and disruptions to global food chains. 'Our wickedly efficient killing technology, global economic systems and resource management that prioritize short-term benefits to humanity have given rise to the human super predator,' says an expert.

A coastal wolf is hunting salmon in British Columbia, Canada.
Credit: Photo by Guillaume Mazille
 
Are humans unsustainable 'super predators'? Want to see what science now calls the world's "super predator"? Look in the mirror.

Research published today in the journal Science by a team led by Dr. Chris Darimont, the Hakai-Raincoast professor of geography at the University of Victoria, reveals new insight behind widespread wildlife extinctions, shrinking fish sizes and disruptions to global food chains.

"These are extreme outcomes that non-human predators seldom impose," Darimont's team writes in the article titled "The Unique Ecology of Human Predators."

"Our wickedly efficient killing technology, global economic systems and resource management that prioritize short-term benefits to humanity have given rise to the human super predator," says Darimont, also science director for the Raincoast Conservation Foundation. "Our impacts are as extreme as our behaviour and the planet bears the burden of our predatory dominance."

The team's global analysis indicates that humans typically exploit adult fish populations at 14 times the rate of marine predators. Humans hunt and kill large land carnivores such as bears, wolves and lions at 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.

Story Source:
The above post is reprinted from materials provided by University of Victoria. Note: Materials may be edited for content and length.

Journal Reference:
  1. C. T. Darimont, C. H. Fox, H. M. Bryan, T. E. Reimchen. The unique ecology of human predators. Science, 2015; 349 (6250): 858 DOI: 10.1126/science.aac4249


University of Victoria. "The unique ecology of human predators." ScienceDaily. ScienceDaily, 20 August 2015. <www.sciencedaily.com/releases/2015/08/150820144837.htm>.