Search This Blog

Saturday, January 7, 2023

Species Fact Profile: California Condor (Gymnogyps californianus)

                                                        California Condor

                                                Gymnogyps californianus (Shaw, 1797)


Range: Historically occurred throughout North America’s Pacific coast, from southern Canada into Mexico.  By the mid-20th century regulated to California.  Extinct in the wild in 1987, but since reintroduced to California, Arizona, and Utah, with additional reintroduction sites planned  
Habitat:  Rocky Shrubland, Oak Savanna, Coniferous Forest, usually found in association with cliffs or large trees, which serve as nest sites
Diet:   Carrion (primarily larger mammals, including marine mammals)
Social Grouping: Not inherently social, or flocking, but have some social structure and pecking order at gatherings
Reproduction: Reach sexual maturity at 6 years old (usually first breeding at 8 years old).  Males perform displays for females, with the head turning bright red and the neck feathers puffed out, then spreading the wings and approaching the female.  If she accepts, she will lower her head.  They usually may pair for life.  Nest on simple scrapes in caves.  Do not nest communally, and will defend nest site aggressively.  Female lays a single bluish-white egg every other year, from January through April.  Eggs weigh 280 grams, measure 9-12 centimeters long by 6-7 centimeters wide.  If the egg is lost, the parents will double-clutch and lay a replacement.  Incubation 53-60 days.  Chicks may take up to a week to completely hatch.  Covered with fuzzy gray down until they reach adult size.  Able to fly at 5-6 months old, but usually remain with parents until second year
Lifespan: 50 Years
      Conservation Status: IUCN Critically Endangered.  CITES Appendix I.  USFWS Endangered.

  • Body length 110-140 centimeters, with a wingspan of 2.5-3 meters (largest wingspan of any North American bird), with unverified reports of spans of 3.5 meters.  Weigh 7-14 kilograms (8-9 on average).  Unlike many birds of prey, females of this species are smaller than males.  Beak is sharp and powerful; unlike Old World vultures, talons are straight and blunt, more suitable for walking than they are for grasping
  • Sexes alike, with uniform black plumage except for a large triangular white patch on the underside of each wing.  The feet and legs are gray.  The head and neck are bare of feathers (except for sparse black feathers on the forehead), with skin color varying from yellow to red-orange, with a black ruff of feathers around the base of the neck.  The bill is ivory-colored.  Juveniles are mottled brown with grayish heads, obtaining adult coloration at 4-5 years of age
  • Only calls being hisses and grunts, inaudible unless close
  • Some difficulty in gaining flight (they lack large sternums), but once aloft than they soar for miles without flapping their wings, reaching speeds of 90 kilometers per hour and heights of 4,600 meters.  May travel up to 250 kilometers in search of food (not migratory, but occupy large home ranges with preferred roosting spots).  Prefer to roost up high (on cliff ledges, in trees) so that they can take to the air easily again (spend more of their time roosting than flying).  Use thermals to soar        
  • Bathe frequently and may spend hours each day preening.  Defecate on their legs (urohidrosis) to cool themselves when they are hot     
  • In October 2021, the San Diego Zoo Safari Park reported the hatching of two unfertilized eggs through parthenogenesis, a first for the species.  Genetic testing confirmed that the chicks had no genetic contribution from a male (chicks hatched decades earlier, genetic status was just confirmed in 2021 – one died at age 2, one at age 8, indicating possible health problems)
  • Adults have no significant natural predators.  Ravens may take eggs, and golden eagles and bears may take young condors.  If threatened, they will regurgitate at the predator.
  • No sense of smell, so prey is detected by sight.  Keep an eye out for smaller vultures, which may circle a carcass but be waiting for a condor to come and open it with its more powerful beak.  May gorge themselves and then go as long as two weeks between feeds
  • Only living member of the genus Gymnogyps (previously placed in Vultur with the Andean condor).  Genus name translates to “Naked Vulture,” species name references California.  “Condor” comes from the Quechua name for the Andean condor
  • Pleistocene range saw this genus/species widespread over North America, as far east as Florida, as well as on Cuba.  No recognized living subspecies, but some fossils may represent extinct subspecies.  Range is believed to have contracted in the modern area with the loss of prehistoric megafauna food base and changes in climate
  • Species was naturally rare due to limited range, slow reproductive rate.  Decline was driven by poaching, lead poisoning (from eating animals which contained lead shot), DDT poisoning, collision with power lines, loss of habitat, and egg collection
  • Population declined to the point that the decision was made to capture all remaining California condors and bring them into captivity for an emergency breeding program, which was met with considerable opposition from animal rights groups.  The last wild condor was captured in 1987, being one of 22 members of the species in existence (read more here).
  • Captive breeding facilities were provided at the San Diego Wild Animal Park and Los Angeles Zoo.  Staff used double-clutching to increase chick production, raising some chicks with puppets to prevent them from imprinting on humans
  • In 1988, trial releases of female Andean condors took place in southern California.  Based on their success, those birds were recaptured (later re-released in South America). 
  • In 1991 and 1992, the first releases of California condors occurred in Big Sur, Pinnacles National Park, and Bitter Creek National Wildlife Refuge, all in California.  An Arizona release site was established in 1996 at Vermilion Cliffs, near the Grand Canyon.  Numbers are increasing, both through births and the reintroduction of additional captive-bred individuals
  • Ridley-Tree Condor Preservation Act of 2008 requires hunters to use non-lead ammunition within condor range.  Captive condors are trained to avoid power-lines prior to release.  Biologists supplement release sites with “clean” carcasses to help avoid lead contamination.  Condor Watch volunteers monitor footage of released birds
  •  The species was culturally significant to many Native Americans; the Wiyot of California believe the condor recreated humanity after they were wiped out by a flood, the Chumash believe it was once a white bird that burned itself black by flying too close to a fire, and the Yokut said that it caused the lunar cycle by eating the moon, and its wings caused eclipses.  Condor bones, paintings, and feather headdresses have been found in Native American graves
  • Species was encountered by Lewis and Clark during their voyage to the Pacific, near the Columbia River.  In 2005, a condor appeared on the commemorative state quarter of California, with John Muir

No comments:

Post a Comment