Greater Yellowstone Ecosystem

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Map of the Greater Yellowstone Ecosystem. The boundaries are not defined uniformly
Wolf in Yellowstone National Park
Bison in the Yellowstone area
Elk in the Yellowstone area

As Greater Yellowstone Ecosystem ( English Greater Yellowstone Ecosystem ) is a natural area in the United States designated. It covers the northwest of the state of Wyoming and the adjacent parts of Montana and Idaho . It is the last large, almost intact ecosystem in the northern temperate zone of the earth and the leading natural laboratory in landscape ecology and geology . It is known worldwide as a recreational area. In addition to Yellowstone National Park , other state-run areas are part of the larger Yellowstone ecosystem: The Gallatin , Custer , Caribou-Targhee , Bridger-Teton and Shoshone National Forests , the National Elk Refuge and the Grand Teton National Park . In addition, it includes some privately owned parcels. In the national forests outside of Yellowstone National Park, ten different wilderness areas , the strictest class of nature reserves in the USA, have been established since 1996 in order to ensure better protection of the habitat. The management of the ecosystem is controversial.


Yellowstone National Park's boundaries were arbitrarily set in 1872 in the hope of encompassing all of the region's geothermal pools. The borders did not coincide with the habitat of the wild animals and plants. In the 1970s, the habitat of grizzly bears in and around the park was used as the minimal boundary of a theoretical Yellowstone ecosystem. The area covered 16,000 km². Since then, the defined area has been broadened. A study from 1994 named an area of ​​76,890 km².

In 1985, various subcommittees of the care the House to the greater Yellowstone ecosystem, those for public lands, national parks and recreation. The result was a report of the research service of the Congress ( Congressional Research Service ) that shortcomings in the coordination between the authorities outlined and stressed that the basic values of the area are under threat.

Conservation measures

Since the declaration of cooperation between all the bodies involved in the Greater Yellowstone Ecosystem, protection projects in the national parks and other federal protected areas have been coordinated and coordinated with state policy. Successful, but controversial, is the recovery of the bison population in Yellowstone National Park, with the result that the herds cross the boundaries of the reserve in winter and migrate to the lower areas used by private cattle breeders . In 2012, an agreement was reached in the state of Montana, according to which bison can continue to cross the park boundary to the north in winter. No grazing animals are kept in the affected area at this time.

The protection of the grizzly bears was a great success. Since the introduction of the Endangered Species Act in 1975 and thanks to the strict orientation of all federal measures in the area on the protection of the species, their numbers rose from 136 animals in 1975 to over 500 animals by the end of 2006. Because of this increase, the US wanted Fish and Wildlife service to protect the species pick up by the federal government in the Greater Yellowstone Ecosystem end of April 2007 and the Bears handed over to the regular protection of states. In 2009, a district court in Montana reversed this decision because the populations for such a step cannot be sufficiently delimited and the effects of global warming on the white-stemmed pine as an important food source for the grizzly were not taken into account. The judgment was confirmed by the appellate authority in November 2011. As a result, the number of bears continues to rise, in 2010 602 grizzlies were counted in the ecosystem.

Spread of the grizzly from 1990 to 2018

The wolf of the subspecies Mackenzie wolf, which became extinct and reintroduced in the 1930s, showed a similar development . Since the beginning of the reintroduction of wolves in 1995 in the national park, the population in the Greater Yellowstone Ecosystem has increased to more than 500 animals, of which reproduce stable for 100 females in the year continued. In March 2008, the Fish and Wildlife Service wanted to lift federal protection under the Endangered Species Act for this species as well and leave the species to the nature conservation authorities of the states. The project was stopped by a federal court in July 2008 after a coalition of nature conservation associations complained that the measures in Wyoming did not meet the level of protection prescribed by the federal government and that the preservation of the population was not guaranteed. In May 2011 the species was finally handed over to the jurisdiction of the states in Idaho and Montana, Wyoming first had to adapt the laws of the state to the requirements of the USFS, so that the state was not responsible for the further protection of the wolf until October 2012. According to the new rules, the wolf in Wyoming's share of the Greater Yellowstone ecosystem outside the national parks and other special protected areas is only hunted with individual shooting permits. In other parts of the state, however, he is considered a predator and can be shot by anyone at any time. For 2010, over 500 wolves were counted in the entire ecosystem, 97 of them in Yellowstone National Park. This is a continuous increase for the region, in 2003, 2004 and 2007 more than 170 animals were recorded in the park itself. The decline in wolves in the park is attributed to the migration that wolves follow their prey. In 2014, a court declared the lifting of the protection of wolves in Wyoming invalid because the agreements between the US Fish & Wildlife Service and the state of Wyoming regarding future wolf management were not binding.

Since the reintroduction of wolves, the elk population in the Yellowstone area has decreased from 17,000–19,000 to 4,635 animals (2011). One main reason is that elk due to the wolves move to higher areas with less food in winter. Further causes are a dry phase between 1998 and 2004, as well as the increase in the number of grizzlies, which appear less as predators and more as food competitors. This in turn has an impact on the vegetation of the area, in particular more willow bushes have been growing in the valley meadows since then .

In the south of the ecosystem there were conflicts over pronghorn and mule deer . All pronghorns and the vast majority of mule deer in the Grand Teton National Park and the surrounding mountain ranges migrate south over the Gros Ventre Range to the valley on the upper reaches of the Green River in winter . With up to 260 km, these are the most widely known migratory movements of the two species. The winter quarters there is threatened by a boom in the use of natural gas deposits that began at the turn of the millennium . In addition, there are the designation of building areas and new road developments. The development endangered the existence of the two animal species in the national park. In 2003, the Bureau of Land Management mistakenly issued two drilling licenses in a section of the valley known as the bottleneck of hiking trails through which almost all pronghorns and many mule deer have to pull. The award was withdrawn after protests. At the beginning of 2010, the nature conservation organization “The Conservation Fund” signed an agreement with landowners according to which the critical section of the hiking route will be permanently secured. In 2012, the US Forest Service also refrained from building fences and other obstacles on the train path; by May 2013 existing facilities were removed. This made the Path of the Pronghorn the first officially recognized migration route for migratory animal species by the federal government.

Grizzly bears, wolves and ravens on carrion


Critics of the larger ecosystem concept claim that it needs to be better tailored to individual animal and plant species. Half a century is not enough to really know how a wild population changes in an ecosystem. For example, ecologists know that the grizzly bears were native to the larger ecosystem before the arrival of Europeans. Unlike today, their population was not isolated then. However, researchers do not know whether the population then or now was larger. Even if the population is stable or even growing slightly today, it cannot be said with certainty that this will also be the case in the long term.

Biotope networking

The Greater Yellowstone Ecosystem is part of the Yellowstone to Yukon Initiative, which has been planned since 1993 , which will create a continuous corridor of protected natural areas from Yellowstone via the Crown of the Continent Ecosystem in the border area between the USA and Canada, the national parks in the center of the Canadian Rockies ( Banff National Park , Jasper National Park , Kootenay National Park , Yoho National Park ) up to the plains of the Yukon River wants to put it under nature protection. This is intended to enable large mammals in particular to migrate over great distances.


  1. ^ Montana Fish, Wildlife & Parks: Park County Bison IBMP Decision Notice , February 28, 2012
  2. ^ US Fish & Wildlife Service: Successful Recovery Efforts bring Yellowstone Grizzly Bears off the Endangered List
  3. Decision of the US District Court for the District of Montana Missoula Division (PDF file; 212 kB)
  4. United States Court of Appeals, Ninth Circuit .: Nos. 09-36100, 10-35043, 10-35052, 10-35053, 10-35054 , November 22, 2011
  5. a b c d National Park Service: Yellowstone National Park - Natural Resource Vital Signs, 2011 (PDF file; 3.41 MB) , page 12
  6. US Fish & Wildlife Service: Interior Department Removes Northern Rocky Mountain Wolves from Endangered Species List
  7. Idahostatesman: Wolves again have federal protection  ( page no longer available , search in web archivesInfo: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , July 19, 2008@1@ 2Template: Dead Link /  
  8. US Fish & Wildlife Service: Service Declares Wyoming Gray Wolf Recovered Under the Endangered Species Act and Returns Management Authority to the State ( Memento of the original from February 5, 2013 in the web archive ) Info: The @1@ 2Template: Webachiv / IABot / archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , Press release dated August 31, 2012
  9. US District Court for the District of Columbia: Judge's order of 23 Sep. 2014
  10. Scott Creel et al .: Glucocorticoid stress hormones and the effect of predation risk on elk reproduction . In: Proceedings of the National Academy of Sciences , 2009
  11. Hall Sawyer, Fred Lindzey, Doug McWhirter: Mule Deer and Pronghorn migration in Western Wyoming. In: Wildlife Society Bulletin , Vol. 33, No. 4 (Winter, 2005), ISSN  0091-7648 , pp. 1266-1273
  12. Denver Post: The haze over Wyoming , May 5, 2005
  13. Joel Berger, Steven L. Cain, K im Murray Berger: Connecting the dots: an invariant migration corridor links the Holocene to the present . In: Biology Letters , 2006 2, pp. 528-531. doi: 10.1098 / rsbl.2006.0508
  14. Casper Star Tribune: BLM withdraws Trapper's Point leases ( Memento of November 18, 2008 in the Internet Archive ) (PDF file; 67 kB), August 15, 2003
  15. The Conservation Fund: The Conservation Fund Protects Funnel Bottleneck on the Path of the Pronghorn  ( page no longer available , search in web archivesInfo: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , February 1, 2010@1@ 2Template: Dead Link /  
  16. Victory! Path of the Pronghorn Restored (WY) ( Memento of the original from February 1, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , May 2013 @1@ 2Template: Webachiv / IABot /
  17. ^ Yellowstone to Yukon Conservation Initiative , accessed October 25, 2010
  18. Ben Goldfarb: Safe Passage . Orion Magazine, December 2015

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