Last documented in Oklahoma in 1969, the Texas kangaroo rat may have disappeared from our state’s southwestern mesquite grasslands. Researchers with the Sam Noble Oklahoma Museum of Natural History have been searching for this rare rodent since 2015 at nearly 200 sites to no avail.
North America boasts 21 species of kangaroo rats – hopping, burrowing rats with large eyes, a long tail, and impressive hind legs. Historically, Oklahoma was home to two species – the Texas kangaroo rat and Ord’s kangaroo rat. More than 45 years have passed since the Texas kangaroo rat was last documented in our state. To find out if this nocturnal rodent can still be found north of the Red River, the Wildlife Diversity Program partnered with Janet Braun, head curator at the Sam Noble Oklahoma Museum of Natural History, University of Oklahoma.
For the last two years, Braun and her team have traveled more than 14,000 miles in seven southwestern counties where mesquite grasslands – the Texas kangaroo rats favored habitat – can be found. Multiple live traps are set near the entrances to individual kangaroo rat burrows before dusk and traps are checked the following morning. So far, 34 percent of the traps (set at 171 sites) have been successful – 1,817 small mammals have been trapped as part of the study, representing 13 species of mice and rats and two species of ground squirrels. Despite the team’s best efforts, they’ve yet to capture a Texas kangaroo rat. Braun plans to continue trapping in 2017 to confirm this mesquite obligate is no longer in Oklahoma.
Though Texas kangaroo rats haven’t yet been documented as part of the study, Braun and team have learned more about southwestern Oklahoma’s small mammal community. Nine new county records have been documented as was a considerable increase in hispid cotton rats last year. More than eight times the number of cotton rats were captured in 2016 than 2015!
With overlapping ranges and similarities in appearances, distinguishing Texas from Ord’s kangaroo rats can be a challenge unless the rats have been captured. Texas kangaroo rats are restricted to mesquite grasslands, are about 13 inches long, have a white-tipped tail and four toes on the hind foot. Ord’s kangaroo rats are more adaptable, living in sandy prairies across the Great Plains, are 10 inches long, seldom have a white-tipped tail and have five toes on the hind foot.