Number 40, Spring 2003

Condors to take flight in Baja Sierras

Last fall's much-heralded flight of a group of condors in Baja California proved to be short-lived.

The condors were flown from the San Diego Zoo to the San Pedro Martir Sierras in August. But turbulence at the atmospheric and human level delayed their release. By the time they took their first flight, the thermal airflow was too weak for the birds to soar over the mountains and learn the geography of the area. To make matters worse, an irritable neighborhood eagle started a squabble that terrified and disoriented the birds, forcing biologists to recapture and secure them for the winter.

Xewe the condor
Xewe, an 11-year-old mentor to the five young condors re-released in the San Pedro Mártir Sierra in May, stretches her wings displaying the tracking device by which biologists follow condor movement in the wild.

After that brief sortie, the adolescent birds and the 11-year-old condor that serves as their mentor spent the winter in their cliff-side aviary – nylon netting draped over a cluster of pine trees – waiting to venture forth once again this spring.

A harsh winter helped create more ideal conditions, providing plentiful carrion for the young condors to find when they took off.

After their release, the condors will spend the next couple of years getting to know the neighborhood, biologists say. The four on-site researchers will monitor their behavior, in part to see how well the artificially raised birds adapt to their natural habitat.

The Baja California Condor Release Project grew out of a binational resource conservation program that UC MEXUS funded in 1997.

UC Riverside earth scientist Richard Minnich, Ernesto Franco Vizcaino, California State University, Monterey Bay, and Horacio de la Cueva, CICESE, were developing a Baja California conservation plan.

During a workshop the scientists attended for stakeholder agencies, the U.S. Fish and Wildlife Services began talking about the distressing number of birds that had fallen victim to various man-made hazards during earlier condor releases. One of the safest places for the condors, the scientists told them, would be Sierra de San Pedro Mártir, part of the condor's historical range.

"It's sufficiently isolated to protect the birds from dangerous human interactions and provide them with plentiful carrion to feed on year-round," says de la Cueva.

Sierra de San Pedro Martir National Park, which reaches up 9,000 feet, is covered in old-growth forests of pine, fir, hemlock and spruce. The incursion of humans is minimal.

Condors haven't been documented there since 1937 when three were spotted in the Enchanted Meadow.

"Although California condors were common in the first half of the last century, these magnificent birds are unknown to the younger generations," said de la Cueva, project leader of the condor release project, led by the Zoological Society of San Diego.

The project involves teaching the Mexican biologists condor care and working with local communities and ranchers to educate them about condor reintroduction efforts.

"Our education plan is to teach (community members) . . . about the local and global importance of environmental conservation," he said.

The California Condor Recovery Program aims to establish three geographically separate populations in California, Arizona, and Baja California Norte, Mexico.

The last California condors were removed from the wild in 1987. Since then, captive breeding programs at the Zoological Society of San Diego, Los Angeles Zoo, and the World Center for Birds of Prey in Idaho have succeeded in increasing their numbers from 27 to more than 170. Today 76 condors live in the wilds of California and Arizona.

The Partnership

In the Baja California Condor Release Project, the Zoological Society of San Diego partnered with Mexico's Secretaria de Medio Ambiente y Recursos Naturales (SEMARNAT), Technical Committee for Recovery of the California Condor in Mexico. The committee contains government, academic and non-governmental institutions such as: Instituto Nacional de Ecología (INE), Dirección General de Vida Silvestre (DGVS), Comisión Nacional de Áreas Naturales Protegidas (CONANP), Procuraduría Federal de Protección al Ambiente (PROFEPA), Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO), the state of Baja California Norte, Universidad Autónoma de Baja California (UABC), Cetro de Investigación Científica y Educación Superior de Ensenada (CICESE).

California Condor

Gymnogyps californianus
(Latin for naked turkey)

Current population: 199
Population low: 22 in 1982
Life span: Up to 75 years
Wingspan: Up to 9.5 feet (3 meters)
Weight: Averages 16-23 pounds
Historic range: British Columbia to northern Baja California and some East Coast States. Condors may have inhabited the Americas as long as 25,000 years ago.
Maturity: Adult plumage and coloration by 5-6 years. Breeds 6-8.
Reproduction: One egg semi-annually
Average incubation: 56 days
Nest site: Hillside cave or crevice
Sexes: no sexual dimorphism (visible differences) between male and female
Feeding: Condors are scavengers
Reasons for decline: Unsustainable mortality rate, most related to human activity, plus low birthrate
Identification points: Numbered wing tags, white/mottled triangle under wings; no head feathers; head black in juveniles or orange/pink in adults