programs Natural Resources

Texas Kangaroo Rat

(Dipodomys elator)

Background

According to biologists, over the last 100 years, the Texas kangaroo rat range has decreased from 13 counties (11 counties in North Texas and two in Southern Oklahoma) to only five counties in Texas.

The reason for the decline is unknown. Kangaroo rats appear to live only in recently disturbed grasslands with exposed bare ground and mostly short grasses. The most widely accepted hypothesis ties the decline to fewer massive grassland disturbances once caused by free-roaming bison herds, prairie dog towns and wildfires. Today the species is found in regularly mowed bar ditches, heavily grazed pastures, piles of debris and the compacted soils and salt-burned scars around old oil and gas infrastructure. The species is poorly understood, however, so very little is known or confirmed about its habitat needs, reproduction or threats to the species.

A U.S. Fish and Wildlife Service (FWS) species status assessment is currently underway and should be completed by late 2019. A listing decision is expected to follow in 2021 after a public review of the assessment.

Research Description

In 2014, the Texas Comptroller of Public Accounts contracted with Texas Tech University (TTU) to take multiple approaches to understanding the threats to and status of the Texas kangaroo rat. The research team conducted more than 800 roadside surveys across the historic range of the species. It gathered genetic material from living kangaroo rats and historic museum collections to analyze if and how gene flow has changed or if there are distinct populations. Based on the survey results, the research team assessed habitat associations and modeled the present distribution and potential habitat of the kangaroo rat. It developed new survey techniques using drones, worked closely with private landowners to gain access to previously unsurveyed ranches and convinced retired researchers to share their findings from unpublished data.

Deliverables Due at Contract End, Oct. 1, 2019

  • Model of current and future habitat
  • Analysis of genetic structure of species across the range to see if, how and where gene flow has been interrupted
  • Examination of coyote scat for evidence of predation
  • Documentation of new survey techniques using drones and satellite imagery
  • Assessment of species status

Why This Research Matters

The Texas kangaroo rat is one of many species on the decline that depends on the vast grassland that once covered the majority of Texas. Its fate, conservation work to protect it and FWS’ response will be telling for future FWS listing work on other grassland-dependent species from the Red River to the Rio Grande.

By establishing a clear baseline for the species based on extensive surveys using traditional methods, TTU’s work has drastically reduced the uncertainty surrounding the status of the species in a clear and transparent fashion. This research has set the groundwork for determining why the kangaroo rat no longer occupies the majority of its range and what can be done to alleviate threats.

The TTU team has established a new survey methodology whereby computer software identifies active kangaroo rat burrows with images taken from drone flights. The tool provides standardized surveys across large areas for identifying and monitoring occupied habitat. This in turn will give companies such as wind and solar farm developers the tools they need to determine whether they will have to contend with kangaroo rat issues if the species is listed.

All of this work is regularly communicated to the Texas Parks and Wildlife Department (TPWD), which was funding similar work at Texas State University. The research team at TTU, TPWD’s mammologist and the FWS biologist overseeing the species status assessment also meet quarterly via phone to discuss the research, ensure clear communication and keep the FWS up to date on the latest data available. Each quarter, FWS receives the latest draft of TTU’s final report, which includes all survey data and current analysis.