CORVALLIS, Ore. As wolf populations grow in parts of the West, most of the focus has been on their value in aiding broader ecosystem recovery but a new study from Oregon State University also points out that they could play an important role in helping to save other threatened species.
In research published today in Wildlife Society Bulletin, scientists suggest that a key factor in the Canada lynx being listed as threatened under the Endangered Species Act is the major decline of snowshoe hares. The loss of hares, the primary food of the lynx, in turn may be caused by coyote populations that have surged in the absence of wolves. Scientists call this a "trophic cascade" of impacts.
The increase in these secondary "mesopredators" has caused significant ecosystem disruption and, in this case, possibly contributed to the decline of a threatened species, the scientists say.
"The increase in mesopredators such as coyotes is a serious issue; their populations are now much higher than they used to be when wolves were common in most areas of the United States," said William Ripple, a professor in the Department of Forest Ecosystems and Society at OSU.
"Before they were largely extirpated, wolves used to kill coyotes and also disrupt their behavior through what we call the 'ecology of fear,'" Ripple said. "Coyotes have a flexible, wide-ranging diet, but they really prefer rabbits and hares, and they may also be killing lynx directly."
Between the decline of their central food supply and a possible increase in attacks from coyotes, the Canada lynx has been in serious decline for decades and in 2000 was listed as a threatened species. It also faces pressure from habitat alteration, the scientists said, and perhaps climate change as lower snow packs further reduce the areas in which this mountain species can find refuge.
In numerous studies in recent years, researchers have documented how the presence of wolves and oth
|Contact: William Ripple|
Oregon State University