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 and piles of debris. Very little is known or confirmed about its habitat needs, movement patterns, or threats to the species.

A U.S. Fish and Wildlife Service (USFWS) species status assessment is currently underway. A listing decision is expected around 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. They 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. They 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to gain access to previously unsurveyed ranches and convinced retired researchers to share their findings from unpublished data. A discussion of these results can be found in the Texas kangaroo rat update webinar linked on this page.

In May 2020, the Comptroller’s office contracted with TTU to evaluate the spatial ecology, dispersal patterns, and metapopulation dynamics of the Texas kangaroo rat across its current distribution in Texas. Spatial use will be compared across the precipitation gradient of the habitat within the range. Previous survey sites will be resampled to assess whether the mammal exhibits a dynamic distribution.

Deliverables Due at Contract End, June 30, 2023

  • Maps of home ranges, foraging sites, burrow sites, and any dispersal events
  • Survey results of historical sites
  • Results of movement and dispersal analyses
  • Discussion of persistence, extinction, and colonization over time
  • Conditions to manage land within the Texas kangaroo rat range

Why This Research Matters

The Texas kangaroo rat is one of many species in decline that depends on the vast grassland that once covered the majority of Texas. Its fate, conservation work to protect it and USFWS’ response will be telling for future USFWS 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. The first research project set the groundwork for determining why the Texas kangaroo rat no longer occupies the majority of its range and what can be done to alleviate threats. The current research project is aimed at continuing the work to determine factors affecting the Texas kangaroo rat’s dynamic distribution.

The TTU team 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). The research team at TTU, TPWD’s mammologist and the USFWS biologist overseeing the species status assessment meet frequently to discuss the research, ensure clear communication and keep the USFWS up to date on the latest data available.