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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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Thursday, March 13, 2014

Just about every peer reviewed research I come across discussing the density of roadways per square kilometer that is optimum for the sustainability of Bears, Wolves and Pumas ranges somewhere between 0.5 to 0.9 kilometers of roadway per square kilometere of high quality habitat......The outside range of roads to sustainability of carnivores is usually determined to be 1.2 square km per sq. mile of quality habitat..............Of course, human population density and prey density(deer, elk, bison, moose, etc) are the other two carnivore variables that biologists factor into their equations of what remaining habitat in North America can sustain populations of wolves,pumas, bears et al....................Interesting that in Europe, Wolves are making a living in more densely populated regions than originally thought possible to foster their existance

Research finds roads reduce grizzly 

bear survival rates

Research finds roads reduce grizzly bear survival rates

Roads through bear country are leading to more grizzly deaths. Photo courtesy Parks Canada/Alex Taylor

Photograph by: Credit: Parks Canada/Alex Taylor

Canmore — Roads and trails criss-crossing grizzly bear habitat
 in Alberta are leading to higher death rates — particularly for
 mama bears and their cubs, new research confirms.Experts
at the Foothills Research Institute have analyzed data collected
 over the past decade by age and sex class to determine the
 affect roads have on survival rates for grizzly bears.

“The strongest relationship to roads and possibility of death
 is for females with cubs,” Gordon Stenhouse, research
scientist and program leader at the institute’s grizzly bear
 program, told a Canmore audience during a speaker series
 event by Bow Valley WildSmart, a conservation program
 aimed at reducing negative human-wildlife interactions.
Similarly, he said young bears are also more likely to get
killed near roadways than older bears.

The research, which is currently undergoing review for
 publication, provides scientific support for a key
 recommendation in the province’s grizzly bear recovery
 strategy — a plan that’s being rewritten this year.
Carrie Sancartier, a spokeswoman for Alberta
 Environment, said Stenhouse’s work is being reviewed
 by the province.
“This information will be considered as part of the grizzly
bear recovery planning process,” she said in an emailed
Grizzly bears were listed as threatened in Alberta in 2010
 after it was estimated there were only about 700 bears
 left in the province.
The population numbers, which will also be updated by
Stenhouse this year, led to the recovery strategy aimed
 at reducing conflicts between bears and people, improving
 knowledge about the animals and decreasing human
-caused mortality.

It suggested roads have a direct impact on mortality and
 outlined recommendations for limiting access.According
 to the strategy, only 0.6 kilometres of roadway should
be permitted for every square kilometre of high-quality
habitat and a threshold of 1.2 kilometres should be set
 in all remaining grizzly bear range.

It suggests lower densities should reduce rates of
human-bear interactions and ultimately reduce human-
caused mortality.
Stenhouse said the new research directly shows a road
 density of 0.85 kilometres per square kilometre directly
 affects grizzly bears.
“We see a decline in population levels,” he said. “So 0.85
 kilometres per square kilometres gives a declining grizzly
 bear population.”
Similarly, they found that bears are less likely to den
 around roads — a finding that suggests building more
 roads in grizzly bear habitat could also reduce their
chance of survival.

Stenhouse said the province’s updated strategy will need
 to continue addressing human-caused mortalities by
 looking at roads. It will also need to consider the fact that
 road densities have increased since the initial strategy
 was released.“I’d say keep at 0.6 or below,” he said.
 “The lower you can get it, the better for bears at the
end of the day. Remember, this isn’t just about grizzly

“It’s about people using the roads and attitude toward
 bears and whether they have firearms.”Indeed, dozens
 of bears continue to die because of humans each year
.A total of 31 grizzly bears died in Alberta in 2013, with
at least 26 being killed by poachers, motorists and
 landowners. It was the highest number of deaths
 since the province suspended the hunt in 2006.


Bruce Jensen said...

Every new road in any good or marginal habitat should be constructed with underpasses for animals. No new road should be built through anything but poor habitat if possible.

Rick Meril said... agree..........just drove from Naples, Florida across the state to Miami,,,,,,,,,Big Cyprus reserve is bisected by a major highway and there are underpasses for animals every mile or so..........In fact, the entire highway is chain linked fenceed to keeep animals from getting killed crossing the road........with these underpasses as their conduit to the other side

Mark LaRoux said...

Another solution is to just have a raised highway. I65 intersects Wheeler Wildlife Refuge on the Tennessee river with little interference due to it being raised the whole length of the crossing (several miles). Admittedly more expensive, it keeps wildlife and cars totally seperated while preventing most negative outcomes from pulloffs (poaching, illegal fishing, etc.).

Rick Meril said...

Mark,,,,,,,,,a great solution if the funds exist