Theplumage is black with patches of white on the underside of the wings; the head is largely bald, with skin color ranging from gray on young birds to yellow and bright orange on breeding adults. Its 3.0 m (9.8 ft)wingspan is the widest of any North American bird, and its weight of up to 12 kg (26 lb) nearly equals that of thetrumpeter swan, the heaviest among native North American bird species. The condor is ascavenger and eats large amounts ofcarrion. It is one of the world'slongest-living birds, with a lifespan of up to 60 years.[6]
Condor numbers dramatically declined in the 20th century due to agricultural chemicals (DDT),poaching,lead poisoning, andhabitat destruction.[7] Aconservation plan put in place by the United States government led to the capture of all the remaining wild condors by 1987, with a total population of 27 individuals.[8] These surviving birds were bred at theSan Diego Wild Animal Park and theLos Angeles Zoo. Numbers rose throughcaptive breeding, and beginning in 1991, condors were reintroduced into the wild. Since then, their population has grown, but the California condor remains one of the world's rarest bird species. By 31 December 2023, theFish and Wildlife Service had updated the total world population of 561,[9] and in the 2024 report, the world population was reported as 569.[10] A population estimate of 565 is provided by the non-profit Ventana Wildlife Society on their website.[11] The condor is a significant bird to many Californian Native American groups and plays an important role in several of theirtraditional myths.[12]
The California condor was described by English naturalistGeorge Shaw in 1797 asVultur californianus;Archibald Menzies collected thetype specimen "from the coast of California" during theVancouver Expedition.[4] It was originally classified in the same genus as theAndean condor (V. gryphus), but, due to the Andean condor's slightly different markings, slightly longer wings, and tendency to kill small animals to eat,[13] the California condor has been placed in its ownmonotypic genus. The generic nameGymnogyps is derived from theGreekgymnos/γυμνος "naked" or "bare", andgyps/γυψ "vulture",[14] while the specific namecalifornianus comes from its location in California. The word condor itself is derived from theQuechua wordkuntur.[15]
A California condor skull
The exacttaxonomic placement of the California condor and the other six species ofNew World vultures remains unclear.[16] Though similar in appearance andecological roles toOld World vultures, the New World vultures evolved from a different ancestor in a different part of the world. Just how different the two are is under debate, with some earlier authorities suggesting that the New World vultures are more closely related tostorks.[17] More recent authorities maintain their overall position in the orderFalconiformes along with the Old World vultures[18] or place them in their own order, Cathartiformes.[19] TheSouth American Classification Committee has removed the New World vultures fromCiconiiformes and instead placed them inIncertae sedis, but notes that a move to Falconiformes or Cathartiformes is possible.[16]
As of the 51st Supplement (2010) of the American Ornithologists' Union, the California condor is in the familyCathartidae of the orderCathartiformes.[20]
ThegenusGymnogyps is an example of arelict distribution. During thePleistocene Epoch, this genus was widespread across theAmericas. From fossils, the FloridianGymnogyps kofordi from theEarly Pleistocene and the PeruvianGymnogyps howardae from theLate Pleistocene have been described.[21] A condor found in Late Pleistocene deposits onCuba was initially described asAntillovultur varonai, but has since been recognized as another member ofGymnogyps,Gymnogyps varonai. It may even have derived from a founder population of California condors.[22]
The California condor is the sole surviving member ofGymnogyps and has no accepted subspecies. However, there is a Late Pleistocene form that is sometimes regarded as apalaeosubspecies,Gymnogyps californianus amplus. Opinions are mixed, regarding the classification of the form as either a chronospecies or a separate species,Gymnogyps amplus.[23]Gymnogyps amplus occurred over much of the bird's historical range – even extending into Florida – but was larger, having about the same weight as theAndean condor. This bird also had a wider bill.[24] As the climate changed during the lastice age, the entire population may have become smaller until it had evolved into theGymnogyps californianus of today,[25][26] although more recent studies by Syverson question that theory.[23]
An adult in flight. Tracking tags can be seen on both wings.
The adult California condor is a uniform black with the exception of large triangular patches or bands of white on the underside of thewings. It has gray legs and feet, an ivory-colored bill, a frill of blackfeathers surrounding the base of the neck, and brownish red eyes.[27] The juvenile is mostly a mottled dark brown with blackish coloration on the head. It has mottled gray instead of white on the underside of itsflight feathers.[28]
The condor's head has little to no feathers, which helps keep it clean when feeding on carrion.[29] The skin of the head and neck is capable of flushing noticeably in response to emotional state.[30] The skin color varies from yellowish to a glowing reddish-orange.[27] The birds do not have truesyringeal vocalizations. They can make a few hissing or grunting sounds only heard when very close.[31]
The upper body and head
The female condor is smaller than the male, an exception to the rule amongbirds of prey (the relatedAndean condor is another exception). Overall length ranges from 109 to 140 cm (43 to 55 in) and wingspan from 2.49 to 3 m (8 ft 2 in to 9 ft 10 in). Their weight ranges from 7 to 14.1 kg (15 to 31 lb), with estimations of average weight ranging from 8 to 9 kg (18 to 20 lb).[28][32] Wingspans of up to 3.4 m (11 ft) have been reported but no wingspan over 3.05 m (10.0 ft) has been verified.[33] Most measurements are from birds raised in captivity, so it is difficult to determine if major differences exist between wild and captive condors.
California condors have the largest wingspan of any North American bird. They are surpassed in both body length and weight only by thetrumpeter swan and the introducedmute swan. TheAmerican white pelican andwhooping crane also have longer bodies than the condor. Condors are so large that they can be mistaken for a small, distant airplane, which possibly occurs more often than that they are mistaken for other bird species.[34]
The middle toe of the California condor's foot is greatly elongated, and the hind toe is only slightly developed. Thetalons of all the toes are straight and blunt and are thus more adapted to walking than gripping. This is more similar to their supposed relatives thestorks[35][36] than to birds of prey andOld World vultures, which use their feet as weapons or organs ofprehension.
The California condor lives in rockyshrubland,coniferous forest, andoak savanna.[1] They are often found near cliffs or large trees, which they use as nesting sites. Individual birds have a huge range and have been known to travel up to 250 km (160 mi) in search ofcarrion.
TheLos Padres Condor Range and River Protection Act of 1992 expanded existing wilderness by 34,200 hectares (84,400 acres) and designated 127,900 hectares (316,050 acres) of new wilderness that provide habitat for the condor in the Los Padres.
The California condor's large flight muscles are not anchored by a correspondingly largesternum, which restricts them to being primarily soarers. The birds flap their wings when taking off from the ground, but after attaining a moderate elevation they largely glide, sometimes going for miles without a single flap of their wings. They have been known to fly up to speeds of 90 km/h (56 mph) and as high as 4,600 m (15,100 ft).[47] They prefer to roost on high perches from which they can launch without any major wing-flapping effort. Often, these birds are seen soaring near rock cliffs, usingthermals to aid them in keeping aloft.[48]
The California condor has a long life span, reaching up to 60 years.[6][7] If it survives to adulthood, the condor has few natural threats other than humans.[49] Because they lack asyrinx, their vocal display is limited to grunts and hisses.[30] Condors bathe frequently and can spend hours a day preening their feathers.[47] Condors also performurohidrosis, or defecate on their legs, to reduce theirbody temperature.[30] There is a well-developed social structure within large groups of condors, with competition to determine a pecking order decided by body language, competitive play behavior, and a variety of hisses and grunts. This social hierarchy is displayed especially when the birds feed, with the dominant birds eating before the younger ones.[50]
Condors begin to look for a mate when they reach sexual maturity at the age of 6.[47] To attract a prospective mate, the male condor performs a display, in which the male turns his head red and puffs out his neck feathers. He then spreads his wings and slowly approaches the female. If the female lowers her head to accept the male, the condors become mates for life.[50] The pair makes a simple nest in caves or on cliff clefts, especially ones with nearby roosting trees and open spaces for landing. A mated female lays one bluish-whiteegg every other year. Eggs are laid as early as January to as late as April.[51] The egg weighs about 280 grams (10 oz) and measures from 90 to 120 mm (3.5 to 4.7 in) in length and about 67 mm (2.6 in) in width. If the chick or egg is lost or removed, the parents "double clutch", or lay another egg to take the lost one's place. Researchers and breeders take advantage of this behavior to double the reproductive rate by taking the first egg away forpuppet-rearing; this induces the parents to lay a second (or even third) egg, which the condors are sometimes allowed to raise.[52][53]
The eggs hatch after 53 to 60 days ofincubation by both parents. Chicks are born with their eyes open and sometimes can take up to a week to leave the shell completely.[30] The young are covered with a grayish down until they are almost as large as their parents. They are able to fly after 5 to 6 months, but continue to roost and forage with their parents until they are in their second year, at which point the parents typically turn their energies to a new nest.[27]Ravens are the main predatory threat to condor eggs, whilegolden eagles andbears are potential predators of condor offspring.
In 2021, the San Diego Zoo reported having had two unfertilized eggs hatch within its breeding program in 2001 and 2009, producing male young byparthenogenesis as indicated by genetic studies. The mothers had been housed with males and had mated before, but the offspring lacked markers of male paternity and showed all-maternal inheritance, suggesting the specific mechanism of parthenogenesis involved automixis, gametic fusion, or endomitosis.[54][55][56] Earlier evidence of similar parthenogenesis in birds found that among the known examples the embryos died before hatching, unlike these condor chicks. Neither chick lived to sexual maturity, preventing data collection on their reproductive potential.[57]
In July 2024, theLA Zoo reported that a record-setting 17 California condor chicks hatched during the year's breeding season, crediting the surge on novel breeding and rearing techniques developed by their condor team. The technique involves introducing 2 to 3 chicks to a single surrogate mature condor who raises them. Due to the endangered status of the California condor, all 17 chicks are to be released into the wild.[58]
Wild condors maintain a large home range, often traveling 250 km (160 mi) a day in search ofcarrion.[59] It is thought that in the early days of its existence as a species, the California condor lived off the carcasses of thePleistocene megafauna, which are largely extinct in North America. They still prefer to feast on large, terrestrialmammalian carcasses such asdeer,goats,sheep,donkeys,horses, pigs,cougars, bears, orcattle. Alternatively, they may feed on the bodies of smaller mammals such asrabbits,squirrels, andcoyotes,aquatic mammals such aswhales andCalifornia sea lions, orsalmon.[60] Bird andreptile carcasses are rarely eaten. Condors prefer fresh kills, but they also eat decayed food when necessary.[60] Since they do not have asense of smell,[61] they spot these corpses by looking for other scavengers, likeeagles and smallervultures, the latter of which cannot rip through the tougher hides of these larger animals with the efficiency of the larger condor. They can usually intimidate other scavengers away from the carcass, with the exception of bears, which will ignore them, andgolden eagles, which will fight a condor over a kill or a carcass.[27] In the wild they are intermittent eaters, often going for between a few days to two weeks without eating,[59] then gorging themselves on 1–1.5 kilograms (2.2–3.3 lb) of meat at once.
A juvenile in theGrand Canyon, with its numbered tag prominent.
The California condor conservation project may be one of the most expensive species conservation projects in United States history,[62] costing over $35 million, including $20 million in federal and state funding, sinceWorld War II.[63] As of 2007, the annual cost for the condor conservation program was around $2.0 million per year.[63] Successful reintroduction of captive-bred condors into the wild has become a multi-step and complex process, fraught with the need to periodically recapture the birds to test for lead poisoning and sometimes the necessity for lead removal bychelation.[64]
A condor chick being fed by a condor head feeding puppet
As the condor's population continued to decline, discussion began about starting a captive breeding program for the birds. Opponents to this plan argued that the condors had the right to freedom and that capturing all of the condors would change the species' habits forever, and that the cost was too great.[65] The project received the approval of theUnited States government, and the U.S. Fish and Wildlife service established the California Condor Recovery Program in 1979.[66] The capture of the remaining wild condors was completed onEaster Sunday 1987, when AC-9, the last wild condor, was captured.[67] At that point, there were only 22 surviving condors, all of them in captivity.[68] The goal of the California Condor Recovery Plan was to establish two geographically separate populations, one in California and the other in Arizona, each with 150 birds and at least 15 breeding pairs.
The study and capture of the remaining California condors was made possible through the efforts ofJan Hamber, an ornithologist with theSanta Barbara Museum of Natural History. Hamber personally captured AC-9,[69] the final wild California condor, and her dedication to the bird's conservation led her to compile decades of field notes into the Condor Archives, a searchable database focused on condor biology and conservation.[69]
The captive breeding program, led by theSan Diego Wild Animal Park andLos Angeles Zoo,[70] and with other participating zoos around the country, including theOklahoma City Zoo and Botanical Garden, got off to a slow start due to the condor's mating habits. However, utilizing the bird's ability to doubleclutch, biologists began removing the first egg from the nest and raising it with puppets, allowing the parents to lay another egg.
Aside from breeding programs, the Condor Recovery Center atOakland Zoo treats condors that are ill fromlead poisoning.[71]
The California condor once numbered only 22 birds, but conservation measures have raised that number to over 500 today.
In 1988, theUnited States Fish and Wildlife Service began a reintroduction experiment involving the release of captiveAndean condors into the wild in California. Only females were released, to eliminate the possibility of accidentally introducing a South American species into the United States. The experiment was a success, and all the Andean condors were recaptured and re-released in South America.[47] California condors were released in 1991 and 1992 in California atBig Sur,Pinnacles National Park andBitter Creek National Wildlife Refuge and in 1996 at theVermilion Cliffs release site in Arizona near the Grand Canyon.[28] The Fish and Wildlife Service designated the Arizona condors as anexperimental, nonessential animal so they would not affect land regulations or development as ranchers were concerned they could be charged with an offense if any birds were injured on their property after the release.[72] Though the birth rate remains low in the wild, their numbers are increasing steadily through regular releases of captive-reared adolescents.[73]
In modern times, numerous causes have contributed to the California condor's decline, both before and after recovery efforts began. For example, between 1992 and 2013, 237 condor deaths occurred in the wild population.[74] The leading cause of mortality in condor nestlings is the ingestion of trash that is fed to them by their parents.[75] Among juveniles and adults,lead poisoning (from eating animal carcasses containing lead shot) is the main cause of death.[76][74]
Its low clutch size (one young per nest) and late age of sexual maturity (≈ 6 years) make the bird vulnerable to artificial population decline.
Inbreeding may be causing increased incidence of fatalchondrodystrophicdwarfism in wild condors, as well as a syndrome presenting with 14 rather than the typical 12 tail feathers.[81] A 2021 study found a surprising degree of genomic diversity in condors, however.[82] Such data allow refinement to conservation strategies, helping mitigate the effects of inbreeding. One of the study's authors hopes to complete genomic analysis of all 22 individuals from which all living condors descend.[81]
Lead poisoning is a significant threat to condors and other avian and terrestrial scavengers[83][84] Fragmented lead ammunition in large game waste is highly problematic for condors due to their extremely strong digestive juices.[85] Blood-lead analysis of wild condors showed lead isotope signature matches to ammunition purchased by researchers near the range of the affected condors.[85][86] In California, the Ridley-Tree Condor Preservation Act went into effect July 1, 2008, requiring that hunters usenon-lead ammunition when hunting in the condor's range.[87] Blood lead levels in golden eagles as well as turkey vultures has declined with the implementation of the Ridley-Tree Condor Preservation Act, demonstrating that the legislation has helped reduce other species' lead exposures aside from the California condor.[88][89] There is no comparable anti-lead-bullet legislation in the other states in which the condor resides.
In 2015, Bruce Rideout, director of the wildlife disease laboratories for San Diego Zoo Global, indicated that lead poisoning is the most common cause of death for juvenile and adult condors in the wild. Among wild deaths with known causes between 1992 and 2013, over 60% (excluding chicks and fledglings) have been as a result of lead poisoning.[74] Due to condors' long lifespan (over 50 years) and relatively late age of sexual maturity (≈ 6 years), and small clutch size in the wild (one egg every year or two), the population is very poorly suited to withstand the neurotoxic effects of lead exposure."[74]
According toepidemiologist Terra Kelly, until all natural food sources are free from lead-based ammunition, "lead poisoning will threaten recovery of naturally sustaining populations of condors in the wild."[74] While researchers and veterinarians involved in the condor recovery program note that hunters who use lead-free ammunition actually provide critical sources of food for condors and other scavengers, they caution that using lead ammunition presents a serious and preventable threat to condors and other wildlife.[74][90][91]
Premature condor death may also occur due to contact withgolden eagles. Evidence from condor release efforts also suggests golden eagles may occasionally kill condors.[92][93]
Collision with power lines can also result in condor death. Since 1994, captive-bred California condors have been trained to avoid power lines and people. Since the implementation of this aversion conditioning program, the number of condor deaths due to power lines has greatly decreased.[94]
"Being vultures, condors not only eat dead animals but they also have been observed eating small pieces of bone [which is especially crucial during the egg-laying period]. Although extremely intelligent, condors can't always tell the difference between small pieces of trash and pieces of bone," according to Tim Hauck, Project Director for the California Condor Reintroduction Program.[95] Indigestible trash can cause impaction, starvation, and death if affected condors do not receive timely medical intervention. Parent birds may unintentionally feed microtrash to nestlings,[96] which some research has shown to be the leading cause of death among wild condor nestlings.[75]
In 2023, Highly PathogenicAvian Influenza (HPAI) infected members of the Utah-Arizona flock, killing 21 condors (including 13 individuals from 8 breeding pairs).[97][98] Other individuals were released back into the wild following medical treatment. Sixteen condors were treated as part of a vaccine trial.[99] As of 2 February 2024, 94 condors had received at least the first of two doses of the vaccine.[100]
During routine winter trapping intended to assess lead levels, blood samples collected from 21 condors were tested for HPAI antibodies. About half the samples showed the presence of antibodies to the H5N1 strain of HPAI, indicating these birds were exposed to the virus and survived naturally.
Nesting milestones have been reached by the reintroduced condors. In 2003, the first nestlingfledged in the wild since 1981.[101] In March 2006, a pair of California condors, released byVentana Wildlife Society, attempted to nest in a hollow tree nearBig Sur, California. This was the first time in more than 100 years that a pair of California condors had been seen nesting in Northern California.[102]
In October 2010, the wild condor population reached 100 individuals in its namesake state of California, plus 73 wild condors in Arizona.[73] In November 2011, there were 394 living individuals, 205 of them in the wild[6][7] and the rest in the San Diego Zoo Safari Park, theSanta Barbara Zoo, the Los Angeles Zoo, theOregon Zoo, and theWorld Center for Birds of Prey inBoise, Idaho. In May 2012, the number of living individuals had reached 405, with 179 living in captivity.[103] By June 2014, the condor population had reached 439: 225 in the wild and 214 in captivity.[104] Official statistics from the December 2016 USFWS recorded an overall population of 446, of which 276 are wild and 170 are captive.[105] A key milestone was reached in 2015 when more condors were born in the wild than died.[106]
As the Recovery Program achieved milestones, a fifth active release site inSierra de San Pedro Mártir National Park, Baja California, Mexico, was added to the three release sites in California and the release site in Arizona.[107][108] In early 2007, a California condor laid an egg in Mexico for the first time since at least the 1930s.[109]
In 2014, Condor #597, also known as "Lupine", was spotted nearPescadero, a coastal community south ofSan Francisco.[112] Lupine had been routinely seen atPinnacles National Park after having been released into the wild at Big Sur the previous year. Younger birds of the central California population are seeking to expand their territory, which could mean that a new range expansion is possible for the more than 60 condors flying free in central California.[113] Also in 2014 the first successful breeding in Utah was reported. A pair of condors that had been released in Arizona, nested inZion National Park and the hatching of one chick was confirmed.[114] The 1,000th chick since recovery efforts began hatched in Zion in May 2019.[115] The California condor was seen for the first time in nearly 50 years inSequoia National Park in late May 2020.[116]
As part of an effort headed by theYurok tribe toreintroduce the condor (Yurok name 'prey-go-neesh') to thecoastal redwoods of northern California, birds hatched at the Oregon Zoo and the World Center for Birds of Prey were released atRedwood National Park in 2022.[117][118] The first condor brought to the Yurok site was called Paaytoqin from theNez Perce language meaning 'Come back'; he is also known as 'Mentor' or #736.[119] He was brought to the site, but not released, to help instruct the younger condors how to behave "because of his calm nature and good disposition".[119] Mentor condors are used to serve as a role model and establish a social hierarchy within a flock as an essential part of its survival.[120]
The first condor to be released was called Poy'-we-son (Yurok for "the one who goes ahead"), followed by Nes-kwe-chokw ("He returns"), Ney-gem' 'Ne-chweenkah' ("She carries our prayers") and 'Hlow Hoo-let' ("At last I (or we) fly!").[119] The youngsters felt at home with one another having lived together at other facilities.[120] As of March 2024 11 birds (4 females and 7 males) have been successfully introduced, with another 5 or more being released this year.[121] An article in theNorth Coast Journal from November 2023 describes the 11 birds with their names and translations.[122] By the end of November 2024, 18 condors have been released at the site.[123]
Acrowdsourcing project called Condor Watch (CW) was started on April 14, 2014, and ended in 2020.[124][125] Hosted by the web portalZooniverse, volunteers were asked to examinemotion-capture images of California condors associated with release sites managed by the United States Fish and Wildlife Service,National Park Service and Ventana Wildlife Society.[126] The tasks on the website included identifying tagged condors and marking the distance to feeding sources such as animal carcasses. Biologists can then use this data to deduce which birds are at risk of lead poisoning.
Condor Watch enabled volunteers, orcitizen scientists, to participate in active research. The project had up 175,000 images to view and assess, far more than the team could hope to view on their own.[125] Lead scientist Myra Finkelstein believes volunteering is fun because it allows enthusiasts to track the "biographies" of individual condors. Citizen science has long been used inornithology, for instance in theAudubon Society'sChristmas Bird Count, which began in 1900 and thebreeding bird survey which began in 1966. McCaffrey (2005) believes this approach not only directly benefits ongoing projects, but will also help train aspiring ornithologists.[127]
Throughout its historic range, the California condor has been a popular subject ofmythology and an important symbol toNative Americans. Unusually,[128] this bird takes on different roles in the storytelling of the different tribes.
TheWiyot tribe of California say that the condor recreated mankind after Above Old Man wiped humanity out with a flood.[129] However, other tribes, such as California'sMono, view the condor as a destroyer, not a creator; they say that Condor seized humans, cut off their heads, and drained their blood so that it would floodGround Squirrel's home. Condor then seized Ground Squirrel after he fled, but Ground Squirrel managed to cut off Condor's head when Condor paused to take a drink of the blood.[130] According to theYokuts people, the condor sometimes ate the moon, causing the lunar cycle, and his wings causedeclipses.[131] TheChumash tribe of Southern California tell that the condor was once a white bird, but it turned black when it flew too close to a fire.[131]
Condor bones have been found in Native American graves,[132] as have condor featherheaddresses.Cave paintings of condors have also been discovered.[133] Some tribes ritually killed condors to make ceremonial clothing out of their feathers.[134]Shamans then danced while wearing these to reach the upper and lower spiritual worlds.[citation needed] Whenever a Shaman died, his clothes were said to be cursed,[135] so new clothing had to be made for his successor.
Some researchers such as Snyder believe that this practice of making ceremonial clothing contributed to the condor's decline, writing that California's Native Americans killed up to 700 condors each year.[135][136] Snyder continues that this figure of 700 is "no doubt an unrealistically high estimate", writing that any estimate "would remain impressively high even if divided by 10".[136] A few tribes were known to have killed condors such as theMiwok, thePatwin, theLuiseño and thePomo but how many is not known and difficult to judge.[137][138][139][140] Using available information, Wilbur writes that "a pre-European loss of condors to Indians might not have exceeded a dozen [12] or so annually."[141] Wilbur concludes that Native Americans might have contributed to the decline of California condors, "but their impact was minor except in highly localized situations."[141]
Colpocephalum californici, a species of louse that exclusively parasitized the California condor until pesticide treatment of the entire remaining condor population under the California Condor Recovery Program resulted inconservation-induced extinction of the species
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^Wallace, William J.; Lathrap, Donald W. (1959). "Ceremonial Bird Burials in San Francisco Bay Shellmounds".American Antiquity.25 (2):262–264.doi:10.2307/277447.JSTOR277447.S2CID163835230.
^Gifford, E.W. (May 8, 1926)."Miwok Cults"(PDF).University of California Publications in American Archaeology and Ethnology.18 (3):394–396. RetrievedApril 20, 2024.The eagle and condor were bird chiefs and their capture or killing was always preceded by the making of meal or seed offerings.
^Kroeber, A.L. (February 27, 1932)."The Patwin and their neighbours"(PDF).University of California Publications in American Archaeology and Ethnology.29 (4): 279. RetrievedApril 20, 2024.Eagles (sul) and condors (molok), were shot, not netted, according to most informants; though one told of a spring noose on a bent-over live oak sapling.
^Bates, C.D.; Hamber, J.A.; Lee, M.J. (1993).The California Condor and the California Indians. Vol. 19. American Indian Art. p. 41.Young birds taken from the nest were raised and then used in a ceremony that culminated in the killing of the bird by strangulation or pressing on its heart.
^Gifford, E.W.; Kroeber, A.L. (July 1, 1937)."Culture Element Distributions: IV Pomo".University of California Publications in American Archaeology and Ethnology.37 (4): 170, 130. RetrievedApril 20, 2024.Whole condor (sul) skin worn by male dancer.
^abWilbur, S. (2021)."Condors and Indians". Symbios Books.Archived from the original on April 21, 2024. RetrievedNovember 18, 2025.
Arredondo, Oscar (1976). "The Great Predatory Birds of the Pleistocene of Cuba". In Olson, Storrs L. (ed.).Collected Papers in Avian Paleontology Honoring the 90th Birthday of Alexander Wetmore. Smithsonian Contributions to Paleobiology. Vol. 27. Translated by Olson, Storrs L. Washington: Smithsonian Institution Press. pp. 169–187.doi:10.5479/si.00810266.27.1.
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