It’s been 6 months since we released 152 Stephens’ kangaroo rats onto the Southwestern Riverside County Multi-Species Reserve (see post SKRs Get TLC). To recap, animals were translocated with their neighbors onto five different experimental plots in the fall 2010. On each plot, prior to translocations, we applied three land-management techniques (mowing, sheep grazing, and controlled burning) to reduce exotic grass cover and open the habitat for the kangaroo rats. In January 2011, we restored half of each plot with native bunch grasses (see post Kangaroo Rats Get Home Improvement).
We were quite excited to see where the kangaroo rats were living after six months. But we knew that since it’s spring, and springtime equals babies, it would be a huge task to recapture all of our translocated kangaroo rats, their offspring, and any additional kangaroo rats that may have dispersed onto plots via dirt roads. We had to set out about 300 traps in order to target every burrow or burrow cluster!We then had to deal with the coyotes: during our one-month assessment, we found coyotes on our sites disturbing our traps. This time, we were determined to better protect our kangaroo rats, so instead of resting between our 11 p.m., 1 a.m., and 3 a.m. trap checks, we were on coyote watch! This meant monitoring each plot with night-vision goggles (awesome!) and scanning sites with spotlights to look for eye shine in the distance. Our nights were quite long, but thankfully, all of our volunteers were up for the challenge (with a little help from caffeine). For five nights, a team of five or six people split up to monitor the plots. I’m happy to say we didn’t have any visits from coyotes, although we definitely heard them in the distance.
I’m also extremely happy to say that we recaptured many of the kangaroo rats we released in the fall, including individuals that we did not capture during our one-month assessment. The adult females were either pregnant or lactating, and there were kangaroo rat babies galore! And we marked and collected genetic samples from 85 new individuals.
In the short term, this translocation has been a success. But our goal is to conduct translocations that are successful in the long term. We will continue to monitor these populations and manage these sites in the following years to determine how release-site preparation and restoration affects kangaroo rat translocation success. As the data rolls in, I will continue to keep you updated.
Maryke Swartz is a senior research technician at the San Diego Zoo Institute for Conservation Research.