Office of External Affairs
Mountain-Prairie Region

NEWS RELEASE

U.S. Fish and Wildlife Service
Mountain-Prairie Region
134 Union Boulevard
Lakewood, Colorado 80228

February 1, 2008   

Contacts:  Al Pfister 970-243-2778 ext 29

                  Diane Katzenberger 303-236-4578

 

Gunnison’s Prairie Dog Populations in Portions of Colorado and New Mexico Warranted For Listing Under the Endangered Species Act

 

The U.S. Fish and Wildlife Service has determined that populations of the Gunnison’s prairie dog located in central and south-central Colorado and north-central New Mexico are warranted for protection under the Endangered Species Act.  However, listing these populations at this time is precluded by pending actions for other species with higher listing priorities.  The Service also determined that Gunnison’s prairie dog populations in Arizona, Utah, and elsewhere in Colorado and New Mexico are not warranted for listing.

 

This finding is expected to be published in the Federal Register within the next week.

 

Populations of Gunnison’s prairie dog can be considered to occur in two separate range portions – higher elevations referred to as montane populations and lower elevations referred to as prairie populations.

 

After determining that the Gunnison’s prairie dog does not meet the definition of threatened or endangered across all of its range, the Service evaluated whether any populations in any significant portion of its range met the criteria to be listed as threatened or endangered. The Service found that Gunnison’s prairie dog populations in the montane portion of the range meet the definition of threatened and are considered significant because they would contribute meaningfully to the ability to conserve the species.

 

The montane habitat found in the northeastern portion of the range (central and south-central Colorado and north-central New Mexico) consists primarily of higher elevation, cooler, and moister plateaus, benches, and intermountain valleys.  This habitat comprises 35-40 percent of the species’ total current range.  Gunnison’s prairie dogs occupy grass-shrub in low valleys and mountain meadows within this habitat

 

The prairie habitat in the southwestern portion of the range (southeastern Utah, southwestern Colorado, northwestern New Mexico, and northern Arizona) consists primarily of lower elevation, warmer, and drier plains and plateaus.  This habitat comprises approximately 60-65 percent of the total range of the species.  Gunnison’s prairie dogs occupy shortgrass and mid-grass prairies within this habitat.

 

In making this finding, the Service analyzed impacts to Gunnison’s prairie dog populations including agricultural land conversion, urban development, oil and gas development, recreational shooting, drought, climate change and determined that the magnitude of these impacts does not cause the species to be in danger of extinction throughout all of its range or likely to become in danger of extinction in the foreseeable future.

 

Of all the factors affecting Gunnison’s prairie dog populations, sylvatic plague is the most significant.  Flea-born plague occurs in regular outbreaks and causes population declines and extirpations.  Because the disease has only been present within the species’ range for approximately 70 years, there has been very little time for resistance to evolve.  It is believed that prairie dogs are highly susceptible to plague because of high population densities, abundant flea vectors, and uniformly low resistance.  Partial or complete recovery following population reductions due to plague have been reported for both white-tailed and black-tailed prairie dogs, but little to no recovery to previous levels has been noted in montane Gunnison’s prairie dog colony die-offs, even after long periods of time.

 

The landscape in the montane portion of the Gunnison’s prairie dog range is characterized by fewer, smaller, and more isolated colonies with minimal to no metapopulation structure.  These factors make the prairie dogs in this habitat highly susceptible to plague-related declines.  Gunnison’s prairie dogs also commonly forage outside of their home territory which may contribute to the communicability of plague. 

 

Gunnison’s prairie dog populations in the moister montane areas have been widely and severely affected by plague.  This may be due in part to higher levels of spring moisture which increases flea numbers, and in turn, plague outbreaks.  Although documented population declines due to plague also occur in the drier prairie portions of the Gunnison’s prairie dog range, evidence shows that many of these populations recover more rapidly from plague outbreaks probably due to the availability of nearby colonizers.

 

After assessing the best available science, the Service has concluded that the Gunnison’s prairie dog is not in danger of extinction or likely to become endangered throughout all of its range; however, within the montane habitat in central and south-central Colorado and north-central New Mexico, the species is likely to become threatened or endangered within the foreseeable future due to plague.  Based on the continued presence of plague and its effects and the average to maximum life span of Gunnison’s prairie dogs, the foreseeable future has been determined to be the year 2042.

 

Habitat type by state:

Arizona:  All habitat within Arizona is considered prairie. 

Colorado:  Montane habitat in Colorado includes the Gunnison, South Park, San Luis Valley, and Southeast population areas.  The La Plata/Archuleta and Southwest population areas are considered prairie habitat.  Montane habitat comprises 80 percent of all available habitat in the state and prairie habitat comprises 20 percent.

New Mexico:  Montane habitat is geographically connected to the Colorado montane portion.  The remaining habitat is considered prairieMontane habitat comprises 17 percent of available habitat in the state and prairie habitat comprises 83 percent.

Utah:  All habitat in Utah is considered prairie.

 

The Service asks the public to continue to submit any new information that becomes available concerning the status of or threats to the Gunnison’s prairie dog.  This information will help to monitor the status of the species and in the formulation of a future proposed listing rule.

 

Today’s finding is the result of a settlement agreement with Forest Guardians and others requiring the Service to submit a status review (also known as a 12-month finding) to the Federal Register by February 1, 2008.

 

The Gunnison’s prairie dog (Cynomys gunnisoni) is a member of the Sciruidae family which includes squirrels, chipmunks, marmots, and prairie dogs. Adult Gunnison’s prairie dogs vary in length from 12 to 15 inches and weigh 23 to 42 ounces, with males averaging slightly larger than females.  They are a yellowish buff color with blackish hairs intermixed.  The tops of their heads, sides of cheeks, and eyebrows are noticeably darker.  The species differs from black-tailed prairie dogs in having a much shorter and lighter colored tail and from other white-tailed species in having grayish-white hairs in the tip of the tail rather than pure white.  Gunnison’s prairie dogs are found on grasslands and semi-desert and montane shrublands at elevations from 6,000 to 12,000 feet.

 

The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals and commitment to public service. For more information on our work and the people who make it happen, visit www.fws.gov.

 

- FWS -

 

                                                                                                         

Questions and Answers

 

Regarding the 12-Month Finding Regarding Gunnison’s Prairie Dog

 

What is the Service’s finding regarding the status of the Gunnison’s prairie dog?

 

The U.S. Fish and Wildlife Service has determined that populations of the Gunnison’s prairie dog located in central and south-central Colorado and north-central New Mexico are warranted for protection under the Endangered Species Act (ESA).  However, listing these populations at this time is precluded by pending actions for other species with higher listing priorities.  The Service also determined that Gunnison’s prairie dog populations in Arizona, Utah, and elsewhere in Colorado and New Mexico are not warranted for listing.

 

Where is the range of the Gunnison’s prairie dog?

 

Populations of Gunnison’s prairie dog can be considered to occur in two separate range portions – higher elevations referred to as montane populations and lower elevations referred to as prairie populations.

 

The montane habitat found in the northeastern portion of the range (central and south-central Colorado and north-central New Mexico) consists primarily of higher elevation, cooler, and moister plateaus, benches, and intermountain valleys.  This habitat comprises 35-40 percent of the species’ total current range.  Gunnison’s prairie dogs occupy grass-shrub in low valleys and mountain meadows within this habitat

 

The prairie habitat in the southwestern portion of the range (southeastern Utah, southwestern Colorado, northwestern New Mexico, and northern Arizona) consists primarily of lower elevation, warmer, and drier plains and plateaus.  This habitat comprises approximately 60-65 percent of the total range of the species.  Gunnison’s prairie dogs occupy shortgrass and mid-grass prairies within this habitat.

 

Habitat type by state:

  • Arizona:  All habitat within Arizona is considered prairie.  (Arizona comprises 27 percent of current overall potential Gunnison’s prairie dog habitat.)
  • Colorado:  Montane habitat in Colorado includes the Gunnison, South Park, San Luis Valley, and Southeast population areas.  The La Plata/Archuleta and Southwest population areas are considered prairie habitat.  Montane habitat comprises 80 percent of all available habitat in the state and prairie habitat comprises 20 percent.   (Colorado comprises 25 percent of current overall potential Gunnison’s prairie dog habitat.)
  • New Mexico:  Montane habitat is geographically connected to the Colorado montane portion.  The remaining habitat is considered prairie.  Montane habitat comprises 17 percent of available habitat in the state and prairie habitat comprises 83 percent.  (New Mexico comprises 45 percent of current overall potential Gunnison’s prairie dog habitat).
  • Utah:  All habitat in Utah is considered prairie.  (Utah comprises 3 percent of current overall potential Gunnison’s prairie dog habitat.)
  • Approximately 43 percent of potential habitat occurs on private lands; 27 percent on State and Federal lands; and 30 percent on Tribal lands.  Tribal lands habitat occurs mostly in Arizona and New Mexico; a large amount is on Navajo lands.

 

What factors can affect the Gunnison’s prairie dog?

 

In analyzing impacts to Gunnison’s prairie dog populations, the Service found that agriculture, urbanization, roads, and oil and gas development each currently affect a small percentage of Gunnison’s prairie dog habitat.  Effects of grazing, while wide-spread, have not resulted in measurable population declines.  More information on the impacts of habitat fragmentation and population isolation is needed, and on the magnitude of the potential impacts posed by increasing oil and gas development.

 

Recreational shooting and pest control continue to be a threat to the Gunnison’s prairie dog throughout its range and contributes to the decline of the species when combined with the effects of disease.  However, these threats are being monitored and managed in all states.  Therefore, the magnitude of this threat does not cause the species to be in danger of extinction throughout all of its range or likely to become in danger of extinction in the foreseeable future.

 

Of all the factors affecting Gunnison’s prairie dog populations, sylvatic plague is the most significant.  Flea-born plague occurs in regular outbreaks and causes population declines and extirpations.  Because the disease has only been present within the species’ range for approximately 70 years, there has been very little time for resistance to evolve.  It is believed that prairie dogs are highly susceptible to plague because of high population densities, abundant flea vectors, and uniformly low resistance.  Partial or complete recovery following population reductions due to plague have been reported for both white-tailed and black-tailed prairie dogs, but little to no recovery to previous levels has been noted in montane Gunnison’s prairie dog colony die-offs, even after long periods of time.

 

The landscape in the montane portion of the Gunnison’s prairie dog range is characterized by fewer, smaller, and more isolated colonies with minimal to no metapopulation structure.  These factors make the prairie dogs in this habitat highly susceptible to plague-related declines.  Gunnison’s prairie dogs also commonly forage outside of their home territory which may contribute to the communicability of plague. 

 

Gunnison’s prairie dog populations in the moister montane areas have been widely and severely affected by plague.  This may be due in part to higher levels of spring moisture which increases flea numbers, and in turn, plague outbreaks.  Although documented population declines due to plague also occur in the drier prairie portions of the Gunnison’s prairie dog range, evidence shows that many of these populations recover more rapidly from plague outbreaks probably due to the availability of nearby colonizers.

 

After assessing the best available science, the Service has concluded that the Gunnison’s prairie dog is not in danger of extinction or likely to become endangered throughout all of its range; however, within the montane habitat in central and south-central Colorado and north-central New Mexico, the species is likely to become threatened or endangered within the foreseeable future due to plague.  Based on the continued presence of plague and its effects and the average to maximum life span of Gunnison’s prairie dogs, the foreseeable future has been determined to be the year 2042.

 

What is currently being done to conserve the Gunnison’s prairie dog?

 

All four states within the range of the Gunnison’s prairie dog assert in their Comprehensive Wildlife Conservation Strategies that the species is deserving of special management consideration.  These Strategies were developed by the states in response to Congressional funding and provide guidance for conservation efforts between federal, tribal, state, local and private entities. 

 

Additionally, the Western Association of Fish and Wildlife Agencies has completed a conservation assessment for the species that describes regulatory status, occupied habitat estimates, limiting factors, and conservation needs for the species.  Conservation planning efforts are underway among state and federal agencies.  All of the States with Gunnison’s prairie dog habitat are in the process of developing State Conservation Plans.  The four plans are in different phases of development but are scheduled for completion by March 2008.  The four States have agreed on a monitoring strategy to determine population trends of Gunnison’s prairie dog across their range.

 

What is the Gunnison’s prairie dog?

 

The Gunnison’s prairie dog (Cynomys gunnisoni) is a member of the Sciruidae family which includes squirrels, chipmunks, marmots, and prairie dogs.  Prairie dogs constitute the genus Cynomys.  Adult Gunnison’s prairie dogs vary in length from 12 to 15 inches and weigh 23 to 42 ounces, with males averaging slightly larger than females.  They are a yellowish buff color with blackish hairs intermixed.  The tops of their heads, sides of cheeks, and eyebrows are noticeably darker.  The species differs from black-tailed prairie dogs in having a much shorter and lighter colored tail and from other white-tailed species in having grayish-white hairs in the tip of the tail rather than pure white.  Gunnison’s prairie dogs are found on grasslands and semi-desert and montane shrublands at elevations from 6,000 to 12,000 feet.

 

How does a “warranted-but-precluded” finding affect the Gunnison’s prairie dog?

 

Upon publication of this finding, the Gunnison’s prairie dog will be added to the candidate species list.  The Service will develop a proposed rule to list the species pursuant to our Listing Priority System. 

Candidate species are plants and animals for which the Service has sufficient information on their biological status and threats to propose them as endangered or threatened under the Endangered Species Act, but for which development of a listing regulation is precluded by other higher priority listing activities.

Candidates are assigned a listing priority based on the magnitude of threats they face, the immediacy of the threats, and their taxonomic uniqueness.  The species’ listing priority dictates the relative order in which proposed listing rules are prepared, with the species at greatest risk being proposed first.  The montane portion of Gunnison’s prairie dog habitat has been assigned a listing priority number of 2, the highest potential priority given its taxonomic status.

 

What protection does the ESA provide to candidate species?

 

Candidate species receive no statutory protection under the ESA.  However, the Service encourages cooperative conservation efforts because they are, by definition, species that may warrant future protection under the ESA.