More than 500 black bears have returned to parts of their historic range in the Great Basin of Nevada, where the species disappeared 80 years ago, scientists say.
A new study says genetic testing confirms that bears are making their way east of the sierra stretching north and south of Lake Tahoe along the California line.
In some cases, recent generations moved hundreds of miles to sites near the Utah line, representing a rare example of large mammals recolonizing areas where "The recovery of large carnivores is relatively rare worldwide", said Jon Beckmann, a conservation scientist at the Wildlife Conservation Society in Bozeman, Montana, who co-authored the new study.
It concludes that the bear populations that originate in the mountain ranges of western Nevada have the genetic diversity necessary to sustain the new subpopulations.
The findings are the result of an badociation between wildlife management and geneticists based on bear hair and blood samples taken for 20 years, said Jason Malaney, an environmental scientist at the University of Nevada, Reno. , who directed the study.
He wrote that the study represents "one of the few empirical examples of genetic consequences of natural recolonization in large mammals."
Carl Lackey, a biologist from the state of Nevada, and Marjorie Matocq, UNR scientist, co-author of the study.
The data provide ammunition for defenders of increased wildlife protection corridors for several species in the basin: a large expanse of desert mountains and the mountain that covers most of Nevada, half of Utah and parts from Idaho, Wyoming, Oregon and California.
The study says that the results are timely and relevant due to the projected climate change and the effects of human population growth.
"As the human footprint expands over time in the region, this level of genetic connection between several mountain ranges may not last without conservation." Black bears prevailed in most of Nevada during the 1800s , but had been devastated in the Great Basin in the early 1900s, mainly due to unregulated hunting, conflicts with ranchers, logging and (19659002) "Over time, bears have benefited from a reduction in felling, combined with better land management practices and an emphasis on conservation, "said the study.
"While barriers such as roads often reduce the gene flow in other large mammals with bodies, black bears in the Great Western Basin occasionally seem to cross these obstacles," the report said.
Beckmann said that the bears have moved to central Nevada, around Tonopah and Austin.
"We are beginning to see them clear in places like Ely" near Highway 50 about 40 kilometers from the Utah line. "
Future steps to help the bears could include the construction of structures Wildlife crossing on highways.
"They are expensive, but in one or two decades they pay for themselves in terms of wildlife connectivity and public safety," Beckmann said.
A series of tunnels and bridges they have been built in eastern Nevada on Highway 93 North of Wells, and there is a large pbadage on Interstate 80 west of Wendover, Utah.
Wyoming has them and one is planned in Southeast Idaho. They use them in Banff National Park in the Canadian Rockies.
"It may take several years, but once they are comfortable with them, they are used regularly," said Beckmann, author of a book on the subject. 19659022]