Pacific Pocket Mouse Makes a Comeback at Camp Pendleton

Debra Shier, the associate director of the recovery ecology team at the San Diego Zoo Wildlife Alliance, released a Pacific pocket mouse at North San Mateo in July 2026. This diminutive rodent, about the size of a human thumb and weighing no more than three pennies, plays a crucial role in maintaining coastal ecosystems. After two decades of decline due to habitat loss, the species was thought to be extinct until one was rediscovered in 1993.

To aid the Pacific pocket mouse, which has been classified as endangered since 1994, the San Diego Zoo Wildlife Alliance initiated the Pacific Pocket Mouse Conservation Program. They have successfully reintroduced a new population into shrubland areas of Marine Corps Base Camp Pendleton, marking only the third reintroduction effort. The recovery plan aims for ten populations before considering the species for downlisting from threatened status. However, concerns linger due to potential impacts of El Niño, which may threaten their delicate habitat.