Statewide Prairie Dog Status Update
Request for Proposals November 2020
Jonah Evans, Mammalogist
Black-tailed prairie dogs (Cynomys ludovicianus) are a crucial component of a functioning shortgrass prairie ecosystem. They are frequently referred to as a “keystone” species because they modify their habitat in such a way that it benefits other species such as swift fox, pronghorn, Sprague’s pipit, horned lark, mountain plover and many more. Much of the historic shortgrass prairie ecosystem has disappeared due to shrub encroachment, fire suppression and agriculture and many of the shortgrass obligate bird species have undergone steep declines in recent decades. Additionally, due to eradication efforts, habitat conversion and plague, black-tailed prairie dogs have declined range-wide and currently inhabit less than 5 percent of their historic range (Kotilar et al. 1999).
In 2004, TPWD developed the Texas Black-tailed Prairie Dog Conservation and Management Plan (BTPD Management Plan) following a petition a few years before to list the species as "threatened" under the Endangered Species Act (ESA). In 2000, USFWS determined that the black-tailed prairie dog warranted listing under the Endangered Species Act, but declined to list the species at that time because there were other species also awaiting listing that were in greater need of protection. Then, in 2009, after an additional review, USFWS determined that the black-tailed prairie dog, “does not warrant protection as a threatened or endangered species under the Endangered Species Act.”
In 2004, TPWD completed an initial survey of prairie dogs in the state (Singhurst 2010). The objectives of this survey were to: 1) estimate the historical (pre-2000) distribution of the species in Texas, and 2) estimate the (2002 to 2004) distribution. From this effort they determined that, “the range of the BTPD in Texas had receded from the southern and eastern historical boundaries and from the western historical boundary in the Trans-Pecos.”
The BTPD Management Plan identified surveillance guidelines and time intervals for prairie dog monitoring. Selected priority areas were to be surveyed every 3 years, and a statewide inventory was to occur every 12 years. However, the next survey didn’t happen until 6 years later in 2010, when TPWD conducted a limited survey focused on key priority areas. The full analysis of this survey was disrupted however due to unexpected budget cuts and staff reductions at the time and the 2010 reports exist only in draft form.
Since 2010, there has been no concerted effort to survey prairie dogs, and the last statewide survey was in 2004. While listing the species as threatened under the Endangered Species Act was not warranted, it is a crucial keystone species that has undergone widespread declines. Periodic surveillance of this species is necessary to identify conservation needs and to ensure it is not continuing to decline.
This project will address goals and objectives identified in the 2015 Land and Water Plan, the 2011 Wildlife Division Strategic Plan, the 2011 Texas Conservation Action Plan, the 2003 Multi-State Conservation Plan for the Black-tailed Prairie Dog, the 2004 Texas Black-tailed Prairie Dog Conservation and Management Plan and the 2005 State Conservation Agreement for Black-tailed Prairie Dogs between TPWD and USFWS. All of these plans directly or indirectly call for the conservation of black-tailed prairie dogs or their habitat, the shortgrass prairie and the use of best available science to conserve our State’s natural resources for present and future generations. This statewide status update will be a key step in the development of a shortgrass conservation initiative. The first goal identified in the 2015 Land and Water plan is to: “Practice, encourage and enable science-based stewardship of natural and cultural resources.” Research to further our knowledge of black-tailed prairie dogs in Texas would fall within this goal and would specifically address the following objectives and strategies:
- Objective — TPWD will be an exemplary steward of the public’s lands and waters by using the best available science for ecosystem-based management.
- Strategy — Conduct strategic research on species, habitats and ecosystems.
- Objective — TPWD will protect and assist in the recovery of threatened, endangered and high-priority species.
- Strategy — Review current knowledge, identify gaps and update the status of high-priority species.
The study design should address these main objectives:
- Objective 1 — Review and summarize Texas Prairie Dog Distribution from previous surveys:
- Review, analyze and summarize previously collected data (to be provided by TPWD).
- Compare 2010 data to 2005 survey data to determine changes in distribution and occupied acres by ecoregion.
- Objective 2 — Determine current Texas prairie dog distribution:
- Review protocols used in previous Texas prairie dog survey efforts (Singhurst 2010).
- Use remote sensing to determine locations of active prairie dog towns in Texas.
- Focus effort on the previously defined prairie dog priority areas.
- Provide ArcGIS (shp) files of prairie dog distribution in Texas.
- Ground truth sites around the state to ensure accuracy of remote sensing data.
- Compare current distribution and acres occupied by ecoregion to the two previous datasets.
- Objective 3 — Develop a habitat suitability model for prairie dogs in Texas:
- Use various environmental datasets (e.g. soils, rainfall, vegetation) to determine the most suitable habitats for black-tailed prairie dogs in Texas.
- Use recent remote-sensing data and ground truthing to ensure vegetation data represents the current habitat conditions.
- Determine areas that could be suitable habitat with appropriate management (e.g. shrub control, grassland modification, etc.)
Development and utilization of computer vision and automated machine learning systems to identify prairie dog burrows from aerial imagery is preferred as an alternative to manually digitizing burrows. Any automated software tools developed for identification of prairie dog burrows will be provided to TPWD at study completion.
Expected Management Implications
Prairie dogs are ecosystem engineers that disproportionately modify their environment in ways that benefit many imperiled bird and mammal species and increase biodiversity. Monitoring changes in the distribution of prairie dogs across Texas is necessary for identifying locations where restoration work may be warranted. This distributional dataset will be used to identify potential focal areas for future shortgrass conservation including areas for potential swift fox or black-footed ferret restoration. Additionally, there were Texas surveys in 2004 and 2010, and this third dataset may provide “trend” data that will allow TPWD biologists to assess the trajectory of prairie dogs in Texas.
- Kotilar, N.B, B.W. Baker, A.D. Whicher, G. Plumb. 1999. A critical review of assumption about the prairie dog as a keystone species. Environmental Management 24:177-192.
- Singhurst, J.R., J.H. Young, G. Kerouac, and H.A. Whitlaw. 2010. Estimating Black-tailed Prairie Dog (Cynomys ludovicianus) distribution in Texas. Texas Journal of Science 62:143-162.