In an effort to replenish the smallest mouse species in North America, 19 endangered Pacific pocket mouse pups have been born at the San Diego Zoo Safari Park since February.
The mice, which currently weigh less than 2 grams, were born as part of the fourth breeding season at the zoo this season.
Zoo officials expect to breed a total of 50 mice and release them into a coastal habitat in Southern California by June.
“Pacific pocket mice are critical to their ecosystem function because they are seed eaters and disperse the seeds of native plants,” said Debra Shier, associate director of applied animal ecology for the San Diego Zoo Institute for Conservation Research. “They also dig burrows that hydrate and increase nutrient cycling.”
Pacific pocket mice are the smallest mouse species in North America and were thought to be extinct in the 1980s. But in 1993, the mice were rediscovered in the wild.
Starting in 2012, 30 of the mice were taken from the remaining wild populations to be bred at the San Diego Zoo Safari Park.