Visitor Counter

hitwebcounter web counter
Visitors Since Blog Created in March 2010

Click Below to:

Add Blog to Favorites

Coyotes-Wolves-Cougars.blogspot.com

Grizzly bears, black bears, wolves, coyotes, cougars/ mountain lions,bobcats, wolverines, lynx, foxes, fishers and martens are the suite of carnivores that originally inhabited North America after the Pleistocene extinctions. This site invites research, commentary, point/counterpoint on that suite of native animals (predator and prey) that inhabited The Americas circa 1500-at the initial point of European exploration and subsequent colonization. Landscape ecology, journal accounts of explorers and frontiersmen, genetic evaluations of museum animals, peer reviewed 20th and 21st century research on various aspects of our "Wild America" as well as subjective commentary from expert and layman alike. All of the above being revealed and discussed with the underlying goal of one day seeing our Continent rewilded.....Where big enough swaths of open space exist with connective corridors to other large forest, meadow, mountain, valley, prairie, desert and chaparral wildlands.....Thereby enabling all of our historic fauna, including man, to live in a sustainable and healthy environment. - Blogger Rick

Subscribe via email to get updates

Enter your email address:

Receive New Posting Alerts

(A Maximum of One Alert Per Day)

Tuesday, August 30, 2011

Wolves as a stabalizing trophic predator: Keeping coyotes in check and therefore leaving more snowshoe hare on the ground for lynx............"Bill Ripple and John Laundre's "THE ECOLOGY OF FEAR" paradigm again and again plays out successfully when "all the cogs and wheels" are at play in natural systems............As we remove or greatly reduce top trophic carnivores from the system, waves of disruption all the way down the food chain take place

Wolves may aid recovery of Canada lynx, a 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 , 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 other large predators helps control populations of grazing ungulates including deer and elk, and also changes their behavior. Where wolves have become established, this is allowing the recovery of forest and stream ecosystems, to the benefit of multiple plant and animal species.

Lacking the presence of wolves or other main predators in both terrestrial and marine environments, populations of smaller predators have greatly increased. Other studies have documented mesopredator impacts on everything from birds to lizards, rodents, marsupials, rabbits, scallops and insects. This includes much higher levels of attacks by coyotes on some ranch animals such as sheep, and efforts attempting to control that problem have cost hundreds of millions of dollars.

Scientists have concluded that exploding mesopredator populations can be found in oceans, rivers, forests and grasslands around the world. "In the absence of wolves, coyote densities and distributions generally expanded in the U.S., into the Midwest, to the northeast as far as Newfoundland, and as far northwest as Alaska," the researchers wrote in their report.

Where wolves recovered, as in Yellowstone National Park, coyote populations were initially reduced by 50 percent, Ripple said. Although more sampling will be required, early evidence indicates that a snowshoe hare recovery may be taking place.

As these issues are factored into decisions about how to manage , the researchers said, it's also important to maintain what they call "ecologically effective" , the researchers wrote in their study. The full value of these top predators, and the numbers of them it takes to achieve a wide range of ecological goals, should be more thoroughly researched and better understood, they said.

No comments: