Editing Greater Yellowstone Ecosystem (section)

====Gray Wolf reintroduction====
{{main|History of wolves in Yellowstone}}
The park is a commonly cited example of [[apex predator]]s affecting an ecosystem through a [[trophic cascade]].<ref>{{Cite news |last=Weston |first=Phoebe |date=2022-06-23 |title='People may be overselling the myth': should we bring back the wolf? |url=https://www.theguardian.com/environment/2022/jun/23/rebalancing-act-bringing-back-wolf-fix-broken-ecosystem-aoe |access-date=2022-06-24 |work=The Guardian |language=en}}</ref> After the reintroduction of the [[gray wolf]] in 1995, researchers noticed drastic changes occurring. [[Elk]], the primary prey of the gray wolf, became less abundant and changed their behavior, freeing riparian zones from constant grazing. The respite allowed willows and aspens to grow, creating habitat for [[North American beaver|beaver]],<ref name=LOE032015>{{cite news|title=Beyond the Headlines|url=http://loe.org/shows/segments.html?programID=15-P13-00012&segmentID=5|access-date=March 22, 2015|work=Living on Earth|date=March 20, 2015}}</ref> [[moose]], and scores of other species. In addition to the effects on prey species, the gray wolf's presence also affected the park's [[grizzly bear]] population. The bears, emerging from hibernation, chose to scavenge off wolf kills to gain needed energy and fatten up after fasting for months. Dozens of other species have been documented scavenging from wolf kills.<ref>{{Cite journal|last1=Smith|first1=Douglas W.|last2=Peterson|first2=Rolf O.|last3=Houston|first3=Douglas B.|date=2003-04-01|title=Yellowstone after Wolves|url=https://doi.org/10.1641/0006-3568(2003)053[0330:YAW]2.0.CO;2|journal=BioScience|volume=53|issue=4|pages=330–340|doi=10.1641/0006-3568(2003)053[0330:YAW]2.0.CO;2|s2cid=56277360 |issn=0006-3568|url-access=subscription}}</ref>