Park staff believe action is needed soon because the mountain goat population in the park is currently at a size where complete removal is achievable in a short timeframe. The estimated growth rate of the population of goats in the park suggests that complete removal in the near future may become unattainable after about three years.
The public comment period for the Mountain Goat Management Plan and Environmental Assessment has been extended through February 15. The plan is available for review and comment at parkplanning.nps.gov/mountaingoat.
The website was taken offline during the government shutdown, which prevented the public from providing comments on the plan. Public access to the website was restored today. The comment period for this plan has been extended through February 15 to ensure that the public has 30 days to review and provide comment. Any written comments received or comments entered into the website prior to the shutdown will be considered.
The National Park Service is encouraging public comment on a proposal to remove nonnative mountain goats from Grand Teton National Park and John D. Rockefeller, Jr. Memorial Parkway. This proposal is to aid in the conservation of a native population of bighorn sheep and protect other park resources and values from the rapidly growing nonnative mountain goat population.
Currently the nonnative mountain goat population within the park is estimated at approximately 100 animals. Resident mountain goats within the park are likely from a population that was introduced outside the park southwest of the Teton Range in the late 1960s and early 1970s. First observed in the Teton Range in 1979, they have now established a breeding population that is growing rapidly.
The Teton Range within the park is also home to a small herd of approximately 80 native bighorn sheep. Prior to 2015, the population was estimated to be approximately 100-125 sheep. This herd is one of the smallest and most isolated in Wyoming, and has never been extirpated or augmented. The Teton Range herd of native bighorn sheep is of high conservation value to the park, adjacent land and wildlife managers, and visitors.
Research indicates that the potential for resource competition and disease transmission between mountain goats and bighorn sheep is evident, and expected to increase. Bighorn sheep are highly susceptible to pathogens and disease transmission. Without active management, the mountain goat population is expected to continue to grow and expand its distribution within the park, threatening the existence of the native Teton Range bighorn sheep herd.
The National Park Service has a responsibility to maintain the ecological role of native species and reduce the potential for local extinction of a species. Management policies call for managing, when feasible, nonnative or “exotic” species that could have a substantial impact on park resources.
Three alternatives to respond to the situation have been identified in the environmental assessment; 1) no action, 2) lethal and nonlethal removal of nonnative mountain goats, and 3) lethal removal of nonnative mountain goats.
The preferred alternative at this time is to use a combination of capture and translocation, and lethal removal methods to remove the mountain goat population in the park. The goal would be to remove the mountain goat population as quickly as possible to minimize impacts to native species, ecological communities and visitors. Goats could be translocated to suitable locations where they are native, or to accredited zoos, or lethally removed. Based on current estimates of mountain goat numbers, significantly reducing or eliminating the population is achievable in the next few years.