Reintroduced Wild Mice Are Now Breeding on Their Own
After years of conservation work that included painstakingly tracking, breeding and releasing almost 100 endangered Pacific pocket mice, researchers from San Diego Zoo Global have discovered that mice reintroduced into Orange County, California’s Laguna Coast Wilderness Park have begun to breed on their own.
The science team made the discovery late last month—just weeks after representatives from San Diego Zoo Global, the U.S. Fish and Wildlife Service and the California Department of Fish and Wildlife released a new group of 25 Pacific pocket mice into a 1.6-acre fenced section of the park. Not only have the released mice that were raised at an off-site breeding facility given birth to offspring, but the second generation of mice—born in the wild habitat—have also begun to produce offspring, without human assistance.
“This is a major milestone for a program that has so many delicate and important stages,” said Debra Shier, Ph.D., Brown Endowed Associate Director of Recovery Ecology at the San Diego Zoo Institute for Conservation Research. “There are four major stages for reintroducing a species to the wild: release, establishment, growth and regulation. Right now, we have reached the growth phase for this population. I think if we continue on this trajectory, we will have successfully established a new population in the wild.”
The research team will continue to provide supplementary food to the Pacific pocket mice as they continue to navigate the wild terrain. The team will also cut holes into the perimeter fence to create a more permeable barrier—moving toward the next stage of the release, which will allow the mice to slowly expand their territory beyond the fence.
The Pacific pocket mouse breeding program is managed by staff at the San Diego Zoo Institute for Conservation Research, working closely with the U.S. Fish and Wildlife Service, the California Department of Fish and Wildlife and OC Parks, for the Laguna Coast Wilderness Park population. Starting in 2012, 34 adult Pacific pocket mice were taken from the three remaining wild populations to participate in this breeding program at an off-exhibit area at the San Diego Zoo Safari Park.
To prepare the mice for their life in the wilderness, the breeding facility utilized air conditioning and humidifiers to mimic the coastal temperatures and humidity levels these mice require. The facility was also equipped with large skylights to make sure these nocturnal animals remained attuned to the rising and setting of the sun, which cues their activities.
Scientists trained the mice to spot potential threats and recognize food that they would likely encounter in their wild surroundings.
The Pacific pocket mouse is the smallest mouse species in North America, with adults typically weighing between 6 and 7 grams—about the same as three pennies. The subspecies, thought to be extinct in the 1980s, was rediscovered in 1993. It is currently listed as Endangered under the U.S. Endangered Species Act. Scientists consider these mice vital to their ecosystem, due to their function as seed dispersers for native plants throughout their habitat. They also dig burrows that hydrate and increase nutrient cycling in the soil, which encourages the growth of native plants.
Bringing species back from the brink of extinction is the goal of San Diego Zoo Global. As a leader in conservation, the work of San Diego Zoo Global includes on-site wildlife conservation efforts (representing both plants and animals) at the San Diego Zoo, San Diego Zoo Safari Park, and San Diego Zoo Institute for Conservation Research, as well as international field programs on six continents.
The work of these entities is inspiring children through the San Diego Zoo Kids network, reaching out through the internet and in children’s hospitals nationwide.
The work of San Diego Zoo Global is made possible by the San Diego Zoo Global Wildlife Conservancy and is supported in part by the Foundation of San Diego Zoo Global.
SAN DIEGO ZOO GLOBAL
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WEBSITE: sandiegozoo.org
Laguna Coast Wilderness Park
18751 Laguna Canyon Road
Laguna Beach, CA 92651
(949)923-2235
lagunacoast@ocparks.com
Park Hours: 7 a.m. to sunset
Parking Lot Hours – 8 a.m. to 5 p.m. Trails open 7 a.m. to sunset.
Trails may be closed for three days or more following rain.
Parking Fee: $3 daily. Machine accepts $1 bills and quarters or Visa/Master Card. Annual passes available to purchase in the park office. Please call ahead for staff availability.
- Park Brochure
- Park Map (updated 9/6/16)
- Parking Map
Laguna Coast Wilderness Park lies within some of the last remaining coastal canyons in Southern California. Forty miles of trails lead the visitor through oak and sycamore woodlands and up onto ridges with expansive scenic vistas. Rocky bluffs tower above the canyon trails.
Visitors to Laguna Coast Wilderness Park can see California as it has existed for thousands of years. The Coastal Sage Scrub community covers hilltops and slopes, along with patches of Native Valley Grassland and Maritime Chaparral. In the canyons visitors can find riparian habitats lined by Willow, Oak, and Sycamore trees. After a plentiful winter rain, the ephemeral streams spring to life. In the summer, you can easily pass through the seasonally dry creek beds.
The park is part of the Natural Community Conservation Planning program, which is designed to protect rare and endangered species, from California Gnatcatcher to Orange-Throated Whiptail, by preserving large tracts of Orange County’s rapidly disappearing Coastal Sage Scrub community. Other species benefit from this preservation, including Mule Deer, Long-tailed Weasel, Bobcat, Red-tailed Hawk, and many more.
Laguna Coast Wilderness Park’s 7,000 acres are part of the South Coast Wilderness area, comprised of Aliso and Wood Canyons Wilderness Park, Crystal Cove State Park, The City of Irvine Open Space, and Laguna Coast Wilderness Park (totaling almost 20,000 acres).
Visit the park’s award-winning Nix Nature Center to learn more about Laguna Coast Wilderness Park and for trail information and orientation.
Activities
Visit Laguna Coast Wilderness Park, where you can hike, mountain bike, run trails, or ride horseback through miles of beautiful Orange County natural lands. (Bring your own shoes, bicycle or horse.) Artists, photographers and writers find plentiful inspiration on the trails.
Regularly scheduled guided tours (by foot or bicycle) are available. These tours cover a wide range of interests, from fitness to botany. Guided by volunteer naturalists and park staff, they are a wonderful way to experience the park. Many kinds of tours are offered each month and can be found listed under “Events and Programs” on the park web page.
The Nix Nature Center offers a location to explore the meaning of parkland through exhibits and wildlife viewing area portals. Here you can enjoy scavenger hunts with the family, and learn from free, fun quarterly wildlife programs featuring live animals, American Indian customs, craft projects, and more.
Special tours can be arranged for groups (not to exceed 20 people). Call Laura Cohen at 949-923-3701 for further information.
Parking is limited so please contact the park office at least two weeks ahead if you plan on bringing a group of 10 or more.
Photo Credit: Laguna Coast Wilderness Park Website
