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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

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Wednesday, October 15, 2014

U. of South Dakota ecologist Carol Johnston has been studying how Beavers have impacted Vogageurs National Park in Minnesota..................This keystone species has left a positive influence on the natural system of Voyageurs even when they abandon a historical dam site by leaving many water pockets that provide valuable habitat. for a myriad of other creatures including Moose(moose need this beaver created habitat that is wet and cool to minimize winter tick infestations) ............The mass of fallen logs, brushy uplands and helter/skelter horizontal vegetation becomes a mecca of life once Beavers move on to develop a new lodge downstream or in a different watershed............After having been largely trapped out of the 218,000 acre park by 1940, a steady resurgence of "natures engineers" took place up until 1990 when as much as 13% of Voyageurs harbored Beaver activity.............Since the early 90's, the Beaver population has again trailed off, seemingly due to a decline in their preferred Aspen tree foodstuff and perhaps increased pressure from Wolves..............However, with increased hunting pressure on lobos(wolf population of 3000 in 2007 now down to 2200-2400 animals in 2014), it will be interesting to see if predation is really the cause of the Beaver decline or if it in fact is a decline in their Aspen preferred habitat.

How beavers have affected ecosystem at Voyageurs National Park

October 9, 2014
South Dakota State University

Felling trees, building dams and creating ponds -- beavers
 have a unique ability to alter the landscape in ways that are 
beneficial to other organisms, according to South Dakota 
State University professor Carol Johnston of the natural 
resource management department. That's why they are 
known as a "keystone species."
The ecologist received a two-year National Science Foundation
 grant for more than $143,000 to compile a book based on her 
previous NSF-funded research on how beavers have affected
 the ecosystem at Voyageurs National Park near International 
Falls, Minnesota.

"Beavers influence the environment at a rate far beyond what 
would be expected given their abundance," said Johnston, who 
has been doing beaver research since the 1980s and authored 
or co-authored 28 of the 37 articles in the compilation.

Beavers create patchiness because they cut down big trees and
 make dams that flood the landscape creating wet meadows and
 marshy vegetation, Johnston explained. However, historical and 
aerial photos from 1927 and 1940 showed solid forests, meaning 
little evidence of beaver activity.

From the 1940s through the 1980s, the beaver population in the 
nearly 218,000-acre park increased steadily, according to
 Johnston. By 1986, 13 percent of the landscape was impounded
 by beavers.

"We saw lots of ponds where before there were none," she said.
 In addition to duck and amphibians, moose and upland mammals
 use this habitat extensively. "Having beaver on the landscape 
creates a lot of biodiversity."

Since 1991, the number of beavers has begun to decrease, 
Johnston pointed out. However, thanks to National Park Service 
officials mapping the active beaver lodges, she can now relate the 
population data to changes in the landscape.
"It's unusual to have both those types of data for such a large area,
" she said. That will allow her to track what happens to the 
landscape when beaver numbers are reduced.
Both predation and depleted food supply may account for the
 beavers' decline.

"Aspen is the preferred food," she said, noting beavers don't
 hibernate and must rely on having a large supply of edible f
ood in their underwater cache to survive the winter.
Beavers forage up to 110 yards from the pond edge, creating 
what Johnston calls a "bathtub ring of conifers" when most of
 the aspen and deciduous trees have been harvested. 
Venturing beyond that comfort zone makes them susceptible 
to predators, she pointed out. "Beavers are a preferred prey f
or wolves."

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