Who else but The Nat would jump at the chance to ensure kangaroo rats were safe from construction holes? In 2020, a local electric company began replacing old power poles throughout Warner Valley—home to the largest remaining population of federally threatened Stephens’ kangaroo rats. They contracted our team to ensure the rats were minimally impacted by the construction.

Replacing power poles begins with digging holes 11 feet deep. The first few feet intersect with underground rodent burrows, leaving unsuspecting animals stranded at the bottom of the holes. Mandates required that nets be installed into hundreds of these holes to catch the federally-protected rats—a task easier said than done.

The initially accepted net design caught many critters, but all kinds of animals including kangaroo rats, insects, and lizards continued to (quite literally) fall through the cracks. In summer 2021 after multiple design iterations, our mammalogist Scott Tremor and the electrical crews tried using repurposed concrete molds made of cardboard to seal off the holes from all sides. Their latest design has been 100 percent effective so far.

“What made it so successful is that the construction crews contributed to the design as much as the biologists,” said Tremor. “Everyone was involved in this solution and, as a result, it’s made everybody’s job easier and prevented harm to a threatened species.”

This ingenious invention is an excellent example of simple tools and stakeholder teamwork achieving a collective conservation goal. Our team will be publishing their design during the next fiscal year so other developers and biologists can apply it to similar projects around the world.

Warner Valley is home to the largest remaining population of Stephens' kangaroo rats.

The initial designs were somewhat successful, but some rats and lizards were still finding their way into the deep holes.

The final design was a perfect fit and, when secured with a board on top, it excluded all animals from all sides.

Posted by Cypress Hansen, Science Communications Manager and Scott Tremor, Mammalogist on June 22, 2023