California Condor (Gymnogyps californianus) Fact Sheet: Population & Conservation Status

Population estimates (as of March 2020) (United States Department of the Interior 2019)

• Total world population: 518
  • Wild free-flying population: 337
    • California: 200
    • Arizona and Utah: 90
    • Baja California, Mexico: 39
  • Captive population: 181
• See California Condor Recovery Program for most recent population counts

Slow population growth rates (Meretsky et al. 2000; D'Elia and Haig 2013)

• Mature slowly
  • Six or more years to reach maturity
• Slow breeding cycle
  • On average, one chick in three years
• Low fecundity
  • One chick per breeding attempt

IUCN

• Red List
  • Critically Endangered (2020 assessment) (BirdLife International 2020)
    • Wild populations remain dependent on intensive management efforts
• Green List
  • Critically Depleted (2023 assessment) (Hermes and Vilchis 2023)
    • Strong conservation legacy
    • Would have become extinct without breeding in managed care and reintroduction efforts
      • Also see A Brief History of Conservation Efforts

CITES

• Appendix I (UNEP 2019)
  • Listed 1975

 U.S. Endangered Species Act (United States Fish & Wildlife Service Endangered Species Database)

• Endangered (California, Arizona)
• Experimental population (Arizona, Utah)

Lead poisoning and exposure (Birdlife International 2015, except as noted)

• California Condor’s strong digestive juices dissolve lead bullets and shot from carcasses
• Affects all age classes (Rideout et al. 2012; Finkelstein et al. 2015a)
• Long-lived bird; harmful levels of lead may build up in an individual’s body over many years (Finkelstein et al. 2012; Kelly et al. 2014)
  • High prevalence of exposure
  • Chronic, sublethal exposure detected
• Exposure may increase as birds in a population become less reliant on managed sites/food provisioning (Kelly et al. 2014)
• Many condors need treatment (Finkelstein et al. 2012)
  • Recapture for treatment is stressful on the birds
  • Brought into veterinary clinics, which prevents individuals from breeding
• 2007 Ridley-Tree Condor Preservation Act (implementation began in 2008)
  • Requires big game hunters to use non-lead ammunition in the California Condor’s range
    • Additional restrictions to take effect by 2019
  • 99% hunter compliance rate in California (as of February 2009)
• Fish and wildlife agencies
  • Programs to distribute free, non-lead ammunition substitutes to hunters (Hunt et al. 2009)

Ingestion of small trash (Rideout et al. 2012; Birdlife International 2015; Campbell 2015; Finkelstein et al. 2015a; United States Department of the Interior 2015, and as noted)

• Materials: Plastic, glass, metal
• Example items: Bottlecaps, nuts, bolts, ammunition cartridges, rags, chunks of pipe, wire
• Well-documented in southern California (Finkelstein et al. 2015b)
• Birds may bring intentionally or later regurgitate to nestlings or near the nest (Finkelstein et al. 2015b)
• Particularly detrimental to chicks (Mee et al. 2007; Walters et al. 2010; Finkelstein et al. 2015b)
  • Crop and digestive tract blocked
  • May inhibit growth and feather development
  • Low chick survival in southern California until active management of nests began in 2007
  • Chicks examined monthly for possible ingestion of trash (Walters et al. 2010)

Shooting/poaching (Birdlife International 2015)

• Awareness campaigns have successfully reduced persecution (Birdlife International 2015; Campbell 2015)
  • Once believed that vultures transmitted diseases
  • Vulture conservation was once perceived to conflict with road construction and other signs of “American progress”
• Still killed by people who view them as troublesome (Campbell 2015)

Thin-shelled eggs (Birdlife International 2015; United States Department of the Interior 2015; Kurle et al. 2016, and as noted)

• Affects one coastal population in Central California
• Coastal condors found to have higher contaminant levels than non-coastal condors
  • Mercury, DDT metabolites, and PCBs
• Ingested and absorbed from feeding on marine mammals (Burnett et al. 2013)
  • California sea lions, dolphins, orca
• Contaminant loads which impair reproductive success not yet established in California Condors
  • May be at risk
  • Further investigations needed

Reintroduction programs (Birdlife International 2015, except as noted)

• Captive breeding and reintroduction programs
  • Large-scale, highly successful
  • Many partnering organizations involved
    • San Diego Zoo Wildlife Alliance
      • UT article featuring "Sisquoc": "Zoo's condor hatches a movement"
    • Los Angeles Zoo
    • Oregon Zoo
    • The Peregrine Fund
  • Vaccinations
    • West Nile virus (Walters et al. 2010; Campbell 2015)
  • Training of California Condors in managed care to help them avoid power lines after release (Mee and Snyder 2007)
• Genetic diversity
  • Closely monitored
  • High genetic diversity prior to genetic bottleneck (D'Elia et al. 2016)
    • 80% of mtDNA diversity lost in two centuries
  • High amount of genetic diversity, despite extinction in the wild (Robinson et al. 2021)
• Management of free-living condors
  • Intensive management needed to produce high survival rates (Walters et al. 2010; Finkelstein et al. 2014; Birdlife International 2015)
    • Mortality would be much higher without management efforts
    • Programs subject to financial and logistical constraints as the number of wild condors grows
  • Management
    • Food provided for released birds (Finkelstein et al. 2015a)
      • “Supplemental food,” “food proffering,” “feeding stations”
    • Twice yearly health assessments
      • Includes treatments for lead poisoning
    • Movements monitored
    • Trash removed from nest areas to limit ingestion; chick monitored (Walters et al. 2010)

San Diego Zoo Wildlife Alliance

• San Diego Zoo Wildlife Alliance

Our partners

• AZA partner institutions
• California Condor Recovery Program – U.S. Fish and Wildlife Service
• California Department of Fish and Wildlife
• The Peregrine Fund
• Ventana Wildlife Society
• Chapultepec Zoo
• University of California, Santa Cruz
• Pennsylvania State University
• Universidad Nacional Agraria La Molina
• Secretaria de Medio Ambiente y Recursos Naturales

Early 1900s (D’Elia and Haig 2013, except as noted)

• 1904: Last reliable report of California Condors north of San Francisco, California
• 1905: Killing or collecting California Condors and their eggs banned in California
• 1906: First study of a California Condor nest
• 1930s: More early field studies (Bukowinski et al. 2007)
  • More systematic studies begin in the 1950s

1950s-1970s (Walters et al. 2010; D'Elia and Haig 2013)

• 1950s: California Condors confined to southern California
• 1953: Carl Koford completes the first major natural history study of the California Condor
• 1967: First national protections under U.S. Endangered Species Preservation Act
  • Designated an endangered species
  • Later, received additional protections under U.S. Endangered Species Act of 1973
• 1969: Based on evidence from Andean Condors, Locke et al. (1969) suggest that California Condors might be susceptible to lead poisoning
• 1970: California Endangered Species Act enacted; California Condor declared endangered in 1971
• 1973: U.S. Endangered Species Act passes; additional protections for California Condors added to 1967 provisions
• 1975
  • California Condor Recovery Team is established
  • First Condor Recovery Plan adopted
    • First recovery plan for any species under the Endangered Species Act
  • About 40 California Condors remain

1980s (Walters et al. 2010; D'Elia and Haig 2013)

• 1980: Recovery Plan revised and initiated
  • Captive breeding recommended due to continued declines
  • About 25-35 California Condors remain
• 1982: Only 22 California Condors remain—20 wild, 2 in managed care—an all-time low
• 1983
  • Wild eggs brought into managed care; first chicks hatched and raised in managed care (Birdlife International 2015)
  • San Diego Zoo Wildlife Alliance hatches its first California Condor chick (Snyder and Snyder 2000)
• 1985: Loss of 40% of remaining wild California Condors
  • Catastrophic loss; cause unknown
  • <10 birds remain in the wild
  • Discussions of whether to trap all remaining wild individuals
• 1987
  • Last wild bird brought into managed care
  • The species is extinct in the wild
  • 27 California Condors are in managed care (10 reared in the wild, 17 reared in managed care)
• 1988
  • First successful mating, egg-laying, and hatching of a California Condor in managed care
  • Experimental releases of Andean Condors into the wild, in preparation for California Condor reintroduction efforts

1990s (Walters et al. 2010; D'Elia and Haig 2013)

• 1992: Releases of captive-bred birds begin in California
• 1993: The Peregrine Fund added as a partner
  • A third captive breeding facility established in Boise, Idaho
• 1995: Releases of birds resume, after correcting behavioral problems
  • Birds trained with power line and human aversion program
• 1996: California Condor releases begin in Arizona
• 1997: California Condor releases begin in Big Sur, California
• Late 1990s: California Condors from the wild are breeding successfully in managed care

2000s

• 2001
  • First nesting attempts by reintroduced birds in the wild (Walters et al. 2010)
    • Arizona and southern California
  • Oregon Zoo begins a captive breeding program (D'Elia and Haig 2013)
  • 58 California Condors live in the wild (D'Elia and Haig 2013)
• 2002: California Condor releases begin in Baja California, Mexico (Walters et al. 2010)
• 2003 and 2004: First chicks of reintroduced birds fledge in Arizona and California (Walters et al. 2010)
• 2007: Ridley-Tree Condor Preservation Act passes
  • 2008: Lead ammunition banned in the California Condor’s range in California (Walters et al. 2010)
  • Full implementation of this law in July 2019

2010s

• 2010: Walters et al. (2010) publish an important review of the California Condor Recovery Program
• 2015: California Condor population grows to 435 birds (268 in the wild, 167 in managed care) (United States Department of the Interior 2015)
• 2017: About 35 wild condors in Baja California; 6 wild-hatched (Ignacio "Nacho" Vilchis, personal communication, 2017)
• 2017: First two condors from a breeding program at Chapultepec Zoo in Mexico City are released into the San Pedro Martir mountains (Baja California) (Ignacio "Nacho" Vilchis, personal communication, 2017)
• 2019: Full implementation of the Ridley-Tree Condor Preservation Act takes effect
  • Requires use of nonlead ammunition for take of any wildlife with a firearm in California

 
*For a detailed timeline of California natural history and recovery efforts, see D’Elia and Haig (2013), p. 8-10. For detailed history of recovery, see sources listed by these authors on p. 7.

*For timelines focusing on habitat protections, see Snyder and Snyder (2005), p. 241-243; Snyder and Synder (2000), p. 273-274.

Puppets resembling adult condors are sometimes used to hand-rear chicks in managed care. For chicks that have not been parent-reared, this minimizes the likelihood of improper imprinting on humans (Snyder and Snyder 2000).

A young bird may later enter a behavior program where they are "mentored" by adult condors.

Thanks largely to successful managed breeding programs, the California Condor is gradually edging further away from extinction.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

California Condors released into the wild receive identificiation tags that can be seen from far away.

This allows scientists to identify and track individual birds, which helps in assessing population trends through time. With so few California Condors in the wild, each bird is unique and valuable.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.