California Condor Life History

Habitat

California Condors have been reintroduced to mountains of southern and central California, Arizona, Utah, and Baja California. Nesting habitats range from scrubby chaparral to forested mountain regions up to about 6,000 feet elevation. Foraging areas are in open grasslands and can be far from primary nesting sites, requiring substantial daily commutes. Condors glide and soar when foraging, so they depend on reliable air movements and terrain that enables extended soaring flight. They are so heavy that they can have trouble taking off, so they often use open, windy areas where they can run downhill or launch themselves from a cliff edge or exposed branch to get airborne. Before captive breeding programs began in the 1980s all remaining condors foraged in an area encompassing about 2,700 square miles; this range is now expanding as the wild population grows. Young condors learn the full extent of their range partly from other more experienced birds.Back to top

Food

California Condors eat carrion of land and marine mammals such as deer, cattle, pigs, rabbits, sea lions, and whales. They swallow bone chips and marine shells to meet their calcium needs. They favor small to medium-sized carcasses, probably because smaller bones are easily consumed and digested. Condors locate carcasses with their keen eyesight (not by smell) by observing other scavengers assembled at a carcass. Once they land they take over the carcass from smaller species, but they are tolerant of each other and usually feed in groups. Condors are wary of humans while feeding, which is probably why they do not use roadkill as a food source. In captivity, condors consume 5–7 percent of their body mass per day to maintain their weight, but because their crop (an enlarged part of the esophagus) can hold 3 pounds of food, they may only have to eat every 2–3 days. Young are fed by regurgitation.Back to top

Nesting

Nest Placement

Condors nest mainly in natural cavities or caves in cliffs, though they sometimes also use trees, such as coast redwood and, historically, the giant sequoia. (As the wild population grows, there is the possibility they may return to the sequoia groves in the Sierra Nevada.) Condors have multiple nesting sites and may switch sites between years. Females make the final decision on which nest location to use.

Nest Description

Condors lay their eggs directly on the dirt floor of a cliff ledge or cave, or they construct loose piles of debris from whatever is available at the nest site, such as gravel, leaves, bark, and bones. Nests have loosely defined boundaries and are usually about 3 feet across and up to 8 inches deep.

Nesting Facts

Behavior

California Condors can cover hundreds of miles in one flight as they soar for hours at a time, looking for carrion. These long-distance travelers pair off during the breeding season but are highly social at roosting, bathing, and feeding sites; individuals recognize one another. Generally, condors are not aggressive towards each other, though dominant birds will threaten opponents by standing erect, inflating air sacs in the head and neck, opening the bill and eventually lunging toward the opponent. Pairs are monogamous. They share nesting duties nearly equally, stay together throughout the year, and usually endure until one member dies. Courtship involves coordinated pair flights, mutual preening, and displays. Young are dependent on their parents for at least 6 months after fledging; consequently most condors do not nest in successive years. Condors bathe frequently; mates and chicks help groom each other’s feathers and skin. They clean up after feeding by rubbing the head and neck on a nearby rock or other surface. Condors sun themselves, which helps dry feathers prior to flight and helps the bird warm up. Condors roost together on horizontal limbs of tall trees, on ledges, or in cliff potholes. Sleeping condors sometimes lie prone on their perch with their heads tucked behind their shoulder blades. Given their size, condors are not normally hunted by other animals, except humans and occasionally Golden Eagles; however, nestlings and eggs are at risk of predation from Common Ravens, Golden Eagles, and black bears. Young condors play, especially as late-stage nestlings, mock-capturing all sorts of objects and vegetation, and leaping about in seeming exuberance.Back to top

Conservation

California Condors are critically endangered and are included in the Partner’s in Flight Yellow Watch List-R for species that are not declining but still vulnerable due to small range or population and moderate threats. It rates a 16 out of 20 on the Continental Concern Score, indicating a species of high conservation concern. As of 2022, all 550 condors now living are descended from 22 birds that were brought into captivity in 1987, in a controversial but successful captive breeding program. Now, over half of them live in the wild in California, Arizona, Utah, and Baja California, Mexico. Their numbers have been rising steadily every year, as captive-bred birds are released and wild pairs fledge young from their own nests. More than 160 additional condors live in captivity at breeding programs at The Peregrine Fund, the Los Angeles Zoo, and the San Diego Zoo. Condors have benefited greatly from the Endangered Species Act and from aggressive efforts to breed them in captivity and rerelease them into the wild, but the survival of the species is still dependent on human intervention. Their major threat is lead poisoning, caused by ammunition fragments in the carcasses they eat. Historically, their decline was also attributed to strychnine-laced carcasses left out for coyote control programs, as well as hunting by humans.

Condor recovery has been slow because of their slow reproductive rate: they produce only 1 egg every 1–2 years and do not achieve sexual maturity until age 6–8 years. Wild birds are still supplied with clean (lead-free) carcasses, but they also feed on their own, sometimes on lead-contaminated carcasses that can result in their deaths. To alleviate the lead-poisoning problem, each condor is caught twice a year to test their blood lead levels. The Peregrine Fund reports that 87 percent of condors tested showed lead in the blood. Birds that test high are treated to remove the lead through a technique called chelation. The only route to self-sustaining wild populations will be by solving the lead-poisoning problem. Promising first steps have been taken, including a 2008 ban on lead ammunition used for hunting in the condor’s California range, and an innovative voluntary program in Arizona.

Credits

Finkelstein, M., Z. Kuspa, N. F. Snyder, and N. J. Schmitt (2015). California Condor (Gymnogyps californianus), version 2.0. In The Birds of North America (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Rosenberg, K.V., J. A. Kennedy, R. Dettmers, R. P. Ford, D. Reynolds, J. D. Alexander, C. J. Beardmore, P. J. Blancher, R. E. Bogart, G. S. Butcher, A. F. Camfield, A. Couturier, D. W. Demarest, W. E. Easton, J. J. Giocomo, R. H. Keller, A. E. Mini, A. O. Panjabi, D. N. Pashley, T. D. Rich, J. M. Ruth, H. Stabins, J. Stanton, and T. Will. 2016. Partners in Flight Landbird Conservation Plan: 2016 Revision for Canada and Continental United States. Partners in Flight Science Committee.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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