California Condor Life History

Habitat

Habitat ScrubCalifornia 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

Food CarrionCalifornia 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

Nest CliffCondors 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
Egg Length:3.6-4.7 in (9.2-12 cm)
Egg Width:2.4-2.7 in (6.2-6.8 cm)
Incubation Period:53-60 days
Nestling Period:163-180 days
Egg Description:Pale blue-green bleaching to white or creamy.
Condition at Hatching:Helpless, covered in white down with eyes open.
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Behavior

Behavior Soaring (raptor)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

Conservation Red Watch ListCalifornia Condors are critically endangered; the species is on the 2016 State of North America's Birds' Watch List, which includes bird species that are most at risk of extinction without significant conservation actions to reverse declines and reduce threats. It rates a 20 out of 20 on the Continental Concern Score, and is a Tri-National Concern Species, and a U.S.-Canada Stewardship species. All of the more than 400 condors now alive are descended from 27 birds that were brought into captivity in 1987, in a controversial but successful captive breeding program. As of 2013, there were more than 230 individuals in the wild in California, Arizona, and Baja California. According to Partners in Flight, about 95% live in the U.S., and 5% in Mexico. The number has been rising steadily each 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, Los Angeles Zoo, and San Diego Zoo. Condors have benefited greatly from the Endangered Species Act and from aggressive efforts to breed them in captivity and re-release them into the wild, but the survival of the species is still dependent on human intervention. The major threat is lead poisoning, caused by ammunition fragments in carcasses they eat. Historically, reasons for their decline also included accidental poisoning from lead and from strychnine-laced carcasses left out for coyote control programs. Hunting by humans also had a substantial effect on condor populations. 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, workers catch each condor twice per year to test their blood lead levels; birds that test high are treated to remove the lead through a technique called chelation. In 2010 the Peregrine Fund reported that 72 percent of condors tested in the Vermilion Cliffs, Arizona, showed lead in the blood, and 34 condors had to be treated. 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.Back to top

Credits

Finkelstein, Myra, Zeka Kuspa, Noel F. Snyder and N. John Schmitt. 2015. California Condor (Gymnogyps californianus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Partners in Flight (2017). Avian Conservation Assessment Database. 2017.

Sibley, D. A. (2014). The Sibley guide to birds, second edition. Alfred A. Knopf, New York, USA.

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