2005 Sheep, Goats, Weeds, and Wildlife Workshop
The purpose of this workshop was to bring together all the diverse interests involved with sheep and goat grazing for weed control along with the wildlife specialists who have concerns about the possible impacts of this practice. The workshop was a success in establishing dialogue and mutual understanding among all interests. Hopefully, the communication started at this workshop will continue. We offer all the presentations from the workshop so that those interested in these issues can continue to refer to all the useful information presented during the workshop.
Grazing by domestic sheep and goats can be an effective tool for controlling noxious weeds on private and public lands; however, there are certain potential complications including impacts on native predators and the possibility of disease transmission. Sheep and goats are most commonly used to control leafy spurge (Euphorbia esula) and spotted knapweed (Centaurea maculosa) but have also been used to graze toadflax (Linaria vulgaris), hound’s-tongue (Cynoglossum officinale), and tansy (Tanacetum vulgare). Many other weed species can also be grazed. To be effective, grazing must be managed intensively, taking into account the length of time grazed, season, density of grazers, species of grazers, phenology, target species, and desired species. Clear objectives for success should be agreed upon before grazing begins and progress should be monitored closely. Revegetation may be necessary to rehabilitate/restore certain areas of heavy weed infestation if site availability, native seed availability, and/or species performance limit native plant establishment.
When livestock are used to graze weeds in the Intermountain West, they provide a prey source and potential attractant to predators such as coyotes, wolves, grizzly bears, black bears, and mountain lions. Wolves and bears are particularly likely to depredate sheep. This causes economic losses to the producer and biological losses to the ecosystem as the predators are generally either relocated or removed from the wild. There are many ways to limit these losses such as grazing during certain seasons, removing livestock carcasses, using a full-time herder, guard dogs, and portable electric fencing in bedding grounds.
Domestic sheep can also affect wildlife through disease transmission. Wild bighorn sheep are susceptible to several diseases carried by domestic sheep and goats and epidemics can decimate wild sheep populations. There are fewer options to limit this type of impact on wildlife populations but the general consensus among wildlife biologists and veterinarians is that grazing of domestic sheep and goats in wild sheep habitat should either be done in a very controlled manner (with a full-time herder to ensure no contact with wild sheep) or not at all.
Lastly, grazing by domestic livestock can affect wildlife habitat through direct competition for desired forbs and grasses. Conversely, grazing may enhance wildlife habitat through weed control. This type of detrimental competition is more easily controlled than other problems through clear identification of management objectives, wildlife species of interest, and livestock species used for grazing.
Overall, the use of domestic sheep and goats to control noxious weeds is a promising additional tool to restore ecosystem health through weed control. Care should always be taken to assure that the grazing does not have significant detrimental impacts. Sometimes, grazing may be the only tool necessary for weed control, but at other times, it might be beneficial to use other methods such as hand-pulling, herbicides, prescribed burns, etc. in conjunction with or in place of grazing. In the end, every weed infestation is site-specific and weed control must be integrated into a unified management strategy considering the biology and ecology of domestic animals and the maintenance of healthy native plants and animals in the target area.
Thanks to everyone who participated!
University of Montana
Speakers & Presentations
Speakers & Presentations
Speakers & Presentations
- Keith Aune - Managing for healthy bighorn sheep in Montana: Lessons from the past and plans for the future
- Liz Bradley - Wolves, Livestock and Weeds: an Ounce of Prevention Goes a Long Ways
- Pachy Burns - Jam to Lamb
- Ray Callaway - Centaurea and herbivory: integrating compensatory growth, root exudation, and competition
- Frances Cassirer - Bighorn sheep interaction with domestic sheep and goats: The Hells Canyon experience
- Mark Drew - Health concerns of grazing small ruminants in bighorn sheep habitat
- Tim Faller - The Effects of Multi-species Grazing on Leafy Spurge Infested Rangelands
- Bill Foreyt - Experimental Disease Transmission Studies with Bighorn Sheep, Domestic Sheep and Domestic Goats
- Kraig Glazier - Kraig.L.Glazier@usda.gov
- Kim Goodwin - Protecting prioritized rangelands from weed spread
- John Helle - Sheep Husbandry Practices
- Carla Hoopes - Landowner driven cooperative weed areas utilizing education and grazing as integrated control methods
- Jim Jacobs - Integrating management strategies: how does grazing fit in?
- Brian Jansen - Bighorn sheep, domestic goats, and a disease epizootic in southern Arizona
- Minette Johnson - Collaborating to prevent and address grizzly bear/livestock conflicts
- Rodney Kott - History of Grazing for Weed Control
- Karen Launchbaugh - Prescribed Grazing: A New Look at an Old Tool
- Fred Lindzey - Creating an attractive nuisance
- Craig Madsen - Have trailer will travel: The economics of natural vegetation management
- Jane Mangold - Restoring weed-infested range and wild lands
- Jane Mangold for Roger Sheley - Ecologically-based invasive plant management: an overview
- Dave Mannix - The need to balance grazing ecology with grazing economics
- Hank McNeel - Procedures to Consider When Using Domestic Animals as Part of an Integrated Weed Management Program
- Jeff Mosley - Sheep or Goat Grazing Effects on Wildlife Habitat: Complementary or Competitive?
- Carolyn Nistler - Wildlife abundance in response to leafy spurge control with sheep
- Bret Olson- Livestock grazing weeds
- Yvette Ortega - Ecological impacts of exotic plant invasions: a case study of knapweed and Chipping Sparrows
- Wayne Pearson - Relationship between insects and long term grazing on noxious weed management
- Steven Seefeldt - It was grazed, now what?
- Bret Taylor - Strategic grazing: taking advantage of differences
- Tom Toman - Noxious Weed Impacts on Elk Country
- John Walker - Using Grazing as a Biological Control Tool
- US Fish and Wildlife Service
- Idaho Coop Wildlife Research Unit, University of Idaho
- College of Forestry and Conservation, University of Montana
- Montana Department of Fish Wildlife and Parks
- Wyoming Game and Fish Department
- Idaho Fish and Game Department
- US Forest Service
- National Wildlife Federation
- USDA, Animal and Plant Health Inspection Services (APHIS)
- Rocky Mountain Elk Foundation
- USDA Sheep Experiment Station
- Montana Wool Growers Association
- The Sheep Institute, Montana State University
- Montana Chapter of the Foundation for North American Wild Sheep (FNAWS)
- Bureau of Land Management, States of Montana and North and South Dakota
- Defenders of Wildlife