The Reintroduction of the Gray Wolf into Yellowstone

A Presentation by:

Alexander Chidester

Amanda Gauker

Christopher Glime

Erik Shilts

Background Information

• 1914: Grey wolves in Yellowstone National Park are viewed as a nuisance and killed off by government paid bounty hunters sent to help farmers and ranchers exterminate them.

• 1996: The Wolf Recovery is started and 35 gray wolves from Canada are reintroduced to Yellowstone

Background Information

Background Information

• By 2002, 14 new wolf packs are sighted within the park, in addition to several other wolf packs outside the park

• There are approximately 271 wolves within Yellowstone National Park today.

• The gray wolf still faces opposition from farmers and ranchers.

• Wolves are tracked accurately using radio collars.

Why are wolves important in Yellowstone?

• The gray wolf was the only known missing animal from a national park. The restoration of the wolf into the national park system is a landmark in ecological restoration.

• Wolves fill a very important role at the top of the food chain that was left vacant with their absence.

• With continued success, the gray wolf will be removed from the endangered species list.

The Debate:

• Should the wolves have been reintroduced?• Public perception of the wolf has changed

over the years, but the wolf still faces much opposition from farmers and ranchers near the park.

• Studies have shown the reintroduction program to very successful in restoring the ecosystem of the park.

The Debate:

• After an absence of wolves for more than 60 years, it became evident to researchers that something was wrong with the ecosystem in Yellowstone. It was determined that it could not function properly until the wolves were returned.

• The reintroduction program faced much opposition and was the cause of many debates, but its success has been clear.

• Wolves helped restore Yellowstone's ecosystem to a stable condition that resembles the way it used to function.

Supporting Evidence

• The presence or absence of wolves in an area has affects on many biological factors.

• Yellowstone National Park is one of the last ecosystems with a full compliment of pre-European settlement species.

• Killing off the dominant predator species destroys the ecosystem integrity.

• This affect was studied by Estes (1996) and McLaren (1994) by documenting ecosystem changes in Isle Royal, Michigan.

• The declining wolf population allowed moose to grow in population size, putting extra strain on balsam fir, a main component of a moose's diet.

• The balsam fir declined from 46% of the over-story in Isle Royal in 1848 to less than 5% in 1994.

• Similar studies in Yellowstone showed a connection between gray wolves, elk and aspen trees.

• Replacement of aspen trees in the over-story ceased in the same years that the wolves were eliminated from Yellowstone.

Supporting Evidence

• Ecosystem: An ecological community together with its environment, functioning as a unit.

• No one species may be removed without hurting the entire ecosystem.

• The gray wolves play an especially vital part of the Yellowstone ecosystem by regulating the populations of the large herbivores.

• It is essential that the public be educated on these issues of ecosystem interdependence.

• Hunters and ranchers must be stopped from killing gray wolves and the wolf must be allowed to grow to its population size of old.

Conclusion