Gunnison Sage-grouse Conservation
Conservation of Gunnison Sage-grouse
The International Union for the Conservation of Nature (IUCN) recognizes the Gunnison sage-grouse as a red-listed, or globally endangered, species (Storch 2007). In 2006, the Audubon Society listed the Gunnison sage-grouse as one of the 10 most endangered birds in North America. In January 2013, the USFWS proposed listing the species as an Endangered Species. In addition, they proposed 1.7 million acres of critical habitat for the species. On Nov. 12, 2014 the agency listed the Gunnison sage-grouse as "threatened" instead of "endangered" which is a more flexible protection status. For more information, visit the USFWS Gunnison Sage-grouse website.
Historic and Current Range
Gunnison sage-grouse current occupied range and historic range. Map provided by the U.S. Fish and Wildlife Service.
Historically, there has been a 90 percent or more loss in Gunnison sage-grouse habitat leading to the current distribution today, (Schroeder et al. 2004, GUSG Range-wide Conservation Plan 2005). The Gunnison Sage-grouse Range-wide Steering Committee estimates the historic range was 21,276 square miles and the current range is estimated to 1,822 square miles, which is 8.5 percent of the historic range, (Schroeder et al. 2004). Currently, Gunnison sage-grouse occur in six Colorado counties out of 22 that they historically occupied, (Braun et al. 2014). The estimated population sizes within each of the extant populations is a matter of significant concern. Only one population, the Gunnison Basin population, is estimated to have more than 500 individuals during the breeding season and that population contains more than 80 percent of all remaining individuals in the species. The remaining seven populations are isolated and small, with high male counts ranging from five to 42 males in recent years. Several populations have disappeared since 1980, (Braun 1995, Young et al. 2000).
The historic abundance prior to 1950 is unknown, but, based on historical documents and interviews, was likely orders of magnitude larger than present. Even during the past decades, lek areas in the Gunnison Basin have seen over 500 displaying males present. Currently, most leks in the Gunnison Basin have fewer than 50 males displaying and many have fewer than 20 males. Approximately 40 percent of the leks in the Gunnison Basin are classified as inactive and no longer have birds displaying on them. In other areas in the range, males have not attended leks for several years nor have new leks been discovered in adjacent areas.
Population Trends and Estimates
2001 - 2014 Lek Counts
Recent high male counts of males attending breeding grounds are provided courtesy of Colorado Parks and Wildlife (CPW). Current counts do not reflect the loss of birds from the 90 percent habitat loss calculated in the Gunnison Sage-grouse Range-wide Conservation Plan, nor the inactive or extirpated leks in any population area. As the Gunnison Sage-grouse Range-wide Conservation Plan points out, lek data is most useful to determine long-term trends rather than population estimates. Sage-grouse populations and lek counts routinely vary from year to year. Comparing particular counts or lek areas can be useful to understand potential and percent decline in local areas. For example, in 1953, one lek area in the Gunnison Basin had over 500 birds attending it on a single day. A recent high count of that Ohio Creek area indicated an over 40 percent decline according to the Range-wide Conservation Plan. In other areas of the range, Gunnison sage-grouse have experienced greater than 90 percent declines on lek areas. Recent counts have highlighted concerns that population numbers in seven of the eight populations are becoming less sustainable and more vulnerable given low counts of males at leks. As mentioned above, there are also significant genetic diversity concerns associated with these small populations.
The counts displayed in the table above represent the high male counts (HMC) of males attending leks in the spring. Salmon colored cells indicate the lowest recorded HMC for that population, and green colored cells indicate the highest recorded HMC for that population. Note that, for the satellite populations, most of the lowest recorded counts occurred from 2009 to 2014 and most of the highest counts were recorded from 2001 to 2006. None of the populations has had its highest count since 2006. Lek count procedures were standardized in 1997, so prior count data was not included. There are two methods that have been used to estimate population sizes based on high male counts. The first estimate, found in most local conservation plans and used for the majority of greater sage-grouse populations, results in an overall spring estimate for the 2014 global Gunnison sage-grouse population of 3,852; the second method, found in the Gunnison Sage-grouse Range-wide Conservation Plan, results in an estimate of 4,724.
Wildlife agencies in the United States now recognize that Gunnison sage-grouse are indicator species for shrub-steppe habitat. An indicator species is one which, because of its unique life history and strong reliance to certain ecosystems, provides biologists with an indication of ecosystem health. These grouse are an ideal indicator species for uplands dominated by sagebrush (Young 1994). For example, they require a variety of habitats such as large expanses of sagebrush with a diversity of grasses and forbs and healthy riparian ecosystems. Their habitat requirements differ during most of the year and differ for sex and age classes. Therefore, the presence of each habitat type in healthy condition in close proximity to winter, lek, nest and brood-rearing habitat is essential. A large percent of each seasonal habitat must be in the later seral stages of ecological succession to meet the requirements of the grouse. If the sagebrush ecosystem is healthy (for example: the soil is stable with little accelerated soil erosion; ecological functioning is maintained with several trophic levels of nutrient cycling; and plant and animal communities are diverse and productive), then grouse populations and productivity will indicate the success of land use management. Surveying trends in land productivity and populations of grouse can be a useful management tool for assessing the sagebrush steppe-ecosystem health.
Habitat Loss and Fragmentation
The key to maintenance of any species is providing sufficient habitat. Some causes of habitat loss and fragmentation for Gunnison sage-grouse in the Gunnison Basin include: recreation, increased road density, the formation of Blue Mesa Reservoir, housing and urban developments, Uranium Mill Tailings Remedial Action, power lines and reduction of riparian areas. USFWS considers development and associated habitat fragmentation from roads, power lines and fencing to be the greatest threat Gunnison sage-grouse face. A second problem is the quality of existing habitat present. Some impacts which cause a decline in habitat quality are: excessive livestock grazing, drought, land treatments, increased elk and deer populations reducing shrub vigor and distribution, and herbicides. Increasingly, oil and gas exploration in the southwestern portion of the species range-wide is threatening habitat for breeding, nesting, and brood-rearing.
An example of the importance of good habitat can be seen in the photos above. Female Gunnison sage-grouse are more likely to have a successful nest when vegetative cover is present. Loss of forbs and grasses can lead to increased risk of predation and decreased chances of success for young broods as they emerge from their nests.
Case study with the Gunnison Climate Working Group: Climate Adaption Demonstration Project
The Nature Conservancy is working with the Gunnison Climate Working Group to reduce the impacts of climate change on nature and people in the Gunnison Basin. The multi-agency collaborative group recently completed the first year of a climate adaptation project to build resilience in riparian and wetland habitats across the Basin. Since 2012, a proactive and energetic collaboration including restoration expert Bill Zeedyk, Colorado Parks and Wildlife, Bureau of Land Management, USDA Forest Service, The Nature Conservancy, Western Colorado University, along with landowners, partners and volunteers, built several hundred rock structures, called one rock dams, zuni bowls and media lunas along ephemeral streams on private and public lands. This collaborative project will help improve and restore Gunnison sage-grouse brood rearing habitat at a previously incised drainage. To view a video about the project created by Claudia Strijek, visit StrijekDesign.com (note: you need QuickTime to view the video) or see the video on YouTube.
Trap and Transplant Program
Colorado Parks and Wildlife began a trap and transplant program in 2009 to augment the satellite populations. Because the satellite populations have been declining for several years and are of significant conservation concern, the program began as a way to add birds to the struggling populations. It is also a way of increasing genetic diversity between the populations and preventing inbreeding. A sustainable number of birds are moved from the Gunnison Basin population to satellite populations every spring and fall. Augmented satellite populations include Crawford, Dry Creek, Dove Creek, Poncha Pass and Pinyon Mesa.
The Gunnison Sage-grouse Range-wide Conservation Plan, published in 2005, can be obtained from the Colorado Parks and Wildlife website. Biologists from the following agencies contributed to the plan: Bureau of Land Management, Colorado Parks and Wildlife, National Park Service, Natural Resources Conservation Service, USDA Forest Service, U.S. Fish and Wildlife Service and the Utah Division of Wildlife Resources.
In the Gunnison Basin, Gunnison County has formed the Gunnison Basin Sage-grouse Strategic Committee which is a county sponsored board with diverse representation from federal and state natural resources agencies, the development, recreational, and environmental communities, the local stock growers, and Gunnison County. The group meets monthly and has worked on issues such as spring road closures, research projects, regulatory mechanisms to reduce impacts to sage-grouse, and development of CCAAs for private landowners and CCAs for public lands. They have also speared headed an 11 county coalition to increase proactive participation by county governments in Gunnison sage-grouse conservation efforts.
The local Gunnison Basin Sage-grouse Conservation Plan was published in 1997. Within the plan, specific conservation goals and objectives are proposed to restore habitat and population numbers of the Gunnison sage-grouse to the Gunnison Basin. In addition, over 50 conservation actions are proposed. Organizations involved with creating the plan include the Black Canyon Audubon Society, Bureau of Land Management, Colorado Parks and Wildlife, Gunnison County Stock Growers Association, Gunnison County, High Country Citizens Alliance, National Park Service, Natural Resource Conservation Service, USDA Forest Service, U.S. Fish and Wildlife Service, and Western Colorado University.
Each local working group (except Cerro-Cimarron-Sims) has created their own local conservation plan: