Monday, March 31, 2014

Wuerthner: apex predators critical to healthy ecosystems




Surprise! The Anthropocene has triggered a trophic cascade. Here's yet another reason young Democrats need to vote in midterm elections:
George Wuerthner, a prolific author, ecologist and longtime critic of grazing on public lands, came to Steamboat Springs in the midst of Agriculture Week on Tuesday to talk about the role of predators, particularly wolves, in healthy natural ecosystems. The theory behind that much talked-about phenomenon, Wuerthner explained, is that when animals like wolves and cougars are removed from the top of a food chain, the numbers and behaviors of prey species are significantly altered. Wolves have, however, aggressively reduced the number of surviving coyote pups by 30 to 40 percent in Glacier and Yellowstone national parks, Wuerthner said. Coyotes are rivals of wolves when it comes to hunting. Mature male cougars tend to dominate large territories that overlap the smaller territories of the three or four females they breed with. When a hunter kills a trophy lion, the removal of that dominant individual allows younger, less effective hunters to occupy the territory. It’s most often these younger lions that interact with human society on the edge of cities like Boulder, Wuerthner said. [Tom Ross, Steamboat Today]

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