Scientists Studying Songbird at Safari Park
May 9, 2011—On the 900-acre Biodiversity Preserve at the San Diego Zoo Safari Park, located in the San Pasqual Valley, away from tourists, a group of scientists listen intently for the distinctive song of the cactus wren, a call that sounds like a sewing machine. In the name of conservation, they keep an eye on nests and wait for a bird to surface.
U.S. Geological Survey, Nature Reserve of Orange County and San Diego Zoo Institute for Conservation Research scientists were at the Safari Park as part of an ongoing study focusing on habitat restoration and understanding population dynamics of a species protected under the Migratory Bird Treaty Act and is listed as a California Species of Special Concern. The research conducted at the Safari Park will contribute to an ongoing USGS effort investigating how habitat fragmentation impacts wildlife populations throughout Southern California and Nevada.
“Our goal in this research is to determine how connected cactus wren populations are to one another and to be able to use this information to inform cactus wren habitat restoration projects,” said Barbara Kus, Ph.D., U.S. Geological Survey Western Ecological Research Center research ecologist. “We can then determine where additional connectivity is needed and make recommendations to guide cactus-planting scenarios that will eventually connect patches.”
In 2007, the Witch Creek wildfire that devastated San Diego County also wreaked havoc on the coastal cactus wren’s habitat. At the Safari Park alone, 600 acres burned, reducing the available cactus scrub, a rare habitat this wren species relies on year round. In Southern California the cactus wren is declining and becoming isolated due to urbanization and habitat loss.
On Monday, a biologist’s hands swiftly affixed tiny metal bands on a cactus wren while feathers were collected for a genetic analysis of the population. Understanding the biology and habitat requirements of this species is an important part of ensuring proper habitat restoration and the cactus wren’s ability to rebound.
San Diego Zoo Institute for Conservation Research scientists have been meticulously restoring cactus scrub at the Safari Park Biodiversity Preserve while monitoring the bird’s abundance, distribution, survivorship and productivity. The natural recovery of the cactus scrub habitat has been very slow and in some areas has been further hampered by the invasion of nonnative grasses.
“Cactus wrens only make nests in prickly pear or cholla catcus greater than 3 feet in height. Without it, they cannot survive,” said Bryan Endress, Ph.D., San Diego Zoo Institute for Conservation Research director of Applied Animal Ecology. “Native cactus and coastal sage scrub habitat is not only beneficial to cactus wrens but also supports a wide range of other native wildlife, and this is one of the reasons San Diego County is globally known as a biodiversity hotspot.”
The multi-disciplinary and multi-agency study’s goal is to add to the knowledge of this species before it becomes endangered. Little is known about the coastal cactus wren and its habitat needs or best practices for restoring cactus scrub habitat.
“Through this collaborative effort, we hope to determine the needs and requirements of this species to aid in its recovery,” said Lisa Nordstrom, Ph.D., San Diego Zoo Institute for Conservation Research scientist. “We are also monitoring cactus wrens at the San Diego Zoo Safari Park Biodiversity Preserve to confirm that our restoration efforts are having a positive effect on their population.”
The San Diego Zoo Institute for Conservation Research is dedicated to generating, sharing and applying scientific knowledge vital to the conservation of animals, plants and habitats worldwide. The work of the Institute includes on site research efforts at the San Diego Zoo and the San Diego Zoo Safari Park (historically referred to as Wild Animal Park), laboratory work at the Arnold and Mabel Beckman Center for Conservation Research, and international field programs involving more than 235 researchers working in 35 countries.
In addition to the Beckman Center for Conservation Research, the Institute also operates the Anne and Kenneth Griffin Reptile Conservation Center, the Frozen Zoo(TM) and Native Seed Gene Bank, the Keauhou and Maui Hawaiian Bird Conservation Centers, Cocha Cashu Biological Research Station, and the Desert Tortoise Conservation Center. The Zoo also manages the 1,800-acre San Diego Zoo Safari Park, which includes a 900-acre biodiversity reserve, and the San Diego Zoo. The important conservation and science work of these entities is supported in part by The Foundation of the Zoological Society of San Diego.