User:Rufous-crowned Sparrow/Sandbox/CaliforniaCondor

From Wikipedia, the free encyclopedia
Jump to: navigation, search
California Condor
California-Condor-Szmurlo.jpg
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Ciconiiformes
Family: Cathartidae
Genus: Gymnogyps
Lesson, 1842
Species: G. californianus
Binomial name
Gymnogyps californianus
(Shaw, 1797)
Synonyms

Genus-level:

  • Antillovultur Arredondo1976
  • Pseudogryphus

Species-level:

For other uses, see Condor (disambiguation).

For Vultur gryphus see Andean Condor

The California Condor, Gymnogyps californianus, is a species of bird in the New World vulture family Cathartidae. It has the largest wingspan of any bird found in North America. The California Condor is currently one of the world's rarest bird species and also one of the greatest conservation success stories.

Currently, this condor only inhabits the western coastal mountains of the United States, Baja California, and the Grand Canyon. It is primarily a scavenger, feeding on carrion. This species belongs to the New World vulture family Cathartidae, which is more closely related to storks than the Old World vultures, which are in the family Accipitridae along with hawks, eagles and kites.

According to a 2005 report of the California Department of Fish and Game, the total population of California Condors both captive and wild is 273.[1]

Taxonomy[edit]

Juvenile California Condor

The genus Gymnogyps is a prime example of a relict distribution. During the Pleistocene, this genus was widespread across the Americas. From fossils, the Floridan Gymnogyps kofordi from the Early Pleistocene and the Peruvian Gymnogyps howardae from the Late Pleistocene have been described. A condor found in Late Pleistocene deposits on Cuba was initially described as Antillovultur varonai, but has since been recognized as another member of Gymnogyps. It even may have been a subspecies of the California Condor.

Today's California Condor is the sole surviving member of Gymnogyps and has no accepted subspecies; although its range greatly contracted during the Holocene, the species always had a small and much interbreeding population. However, there is a Late Pleistocene palaeosubspecies, Gymnogyps californianus amplus, which occurred over much of the bird's historical range - even extending into Florida - and was larger, having about the same weight as the Andean Condor. This bird also had a wider bill [1]. As the climate changed during the last ice age, the entire population became smaller until it had evolved into the Gymnogyps californianus californianus of today [2][3].

The Andean Condor of genus Vultur, the California Condor's closest surviving relative, differs from it by having slightly different markings, slightly longer wings, and a tendency to actually kill small animals to eat [4].

See Sibley-Ahlquist taxonomy for an alternative classification.

Description[edit]

California Condor

The adult California Condor is a uniform black, with the exception of a frill of black feathers nearly surrounding the base of the neck and, especially in the male, large triangular patches or bands of white on the underside of the wings. The feathers are meticulously kept clean by the bird. As an adaptation for hygiene, the head and neck have few feathers, which exposes the skin to the sterilizing effects of dehydration and ultraviolet light at high altitudes. The skin of the head and neck is capable of flushing noticeably in response to emotional state, which serves to communicate between individuals. The skin color varies from nearly white to a glowing reddish-purple. The juvenile is mostly a mottled dark brown with blackish coloration on the head. It has gray instead of white on its flight feathers.

The female, contrary to the usual rule among true birds of prey, is smaller than the male. Overall length can range from 117 to 135 cm (46 to 53 inches) and the wingspan averages around 2.77 m (9.1 feet)[5]. The weight can range from 7 to 14 kg (15.5 to 31 lbs), with estimations of average weight ranging from 8 to 9 kg (17.6 to 20 lbs). Most measurements are from birds raised in captivity, so determining if there are any major differences in measurements between wild and captive condors is difficult. California Condors have the biggest wingspan of any North American bird and are surpassed only by Trumpeter Swan and the introduced Mute Swan in both weight and length. The American White Pelican and Whooping Crane also have longer bodies than the condor. These condors can be mistaken for a small, distant airplane, which possibly occurs more often than they are mistaken for other species of bird[6].

On its foot, the middle toe is greatly elongated and the hind one is only slightly developed. The talons of all the toes are straight and blunt, and are thus more adapted to walking. This is more similar to their close relatives the storks than to birds of prey and Old World vultures, who use their feet as weapons or organs of pretension.


Distribution and Habitat[edit]

California Oak savanna on the east flank of Sonoma Mountain.

In modern times, the California Condor used to roam across the American Southwest. However, the last wild bird was taken into captivity for the breeding program in 1987. Recently, captive-bred condors have been released in southern California, in Baja California, and at the Grand Canyon. [7]

The condors live in rocky scrubland, coniferous forests, and oak savannas[8] . 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 150 miles in search of carrion.


Ecology and Behavior[edit]

When in flight, the movements of the condor are remarkably graceful. The lack of a large sternum to anchor their correspondingly large flight muscles 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 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, using the heat thermals to aid them in keeping aloft.

The California Condor has one of the longer lifespans of birds, reaching up to fifty years. If they survive to adulthood, the condor has no natural predator other than humans.

Diet[edit]

Wild condors inhabit large territories, often traveling 250 km (150 miles) in search of carrion. In the early days of its existence as a species, it is thought that the California Condor lived off of the carcasses of the "megafauna", which are now extinct in North America. They still prefer to feast on large, terrestrial mammalian carcasses such as deer, goats, sheep, donkey, horse, pigs, mountain lions, bears or cattle. Since they do not have a sense of smell[9], they spot these corpses by looking for other scavengers, like smaller vultures and eagles, who cannot rip through the tougher hides of these larger animals with the efficiency of the larger condor. Alternatively, they may feed on the bodies of smaller mammals, such as rabbits or coyotes, aquatic mammals, such as whales and sea lions, or salmon. Bird and reptile carcasses are rarely eaten. They can usually intimidate other scavengers, with the exception of bears, which will ignore them, and Golden Eagles, which will fight a condor over a kill or a carcass. In the wild they are intermittent eaters, often going for a few days without eating, then gorging themselves on several pounds at once, sometimes to the point of being unable to lift themselves off the ground.

File:BirdCalCondor.jpg
California Condor


Reproduction[edit]

To attract a prospective mate, the male condor does a display. In the display, 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 accepts the male, the pair become mates for life. After mating, the female lays one or two bluish-white eggs every other February or March. The eggs weigh about 280 grams (10 oz) and measure from 90 to 120 mm (3.5 to 4.7 inches) in length and 67 mm (2.6 inches) in width. The eggs hatch after 53–60 days of incubation by both parents. If the chick or egg is lost or removed, they 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 for hand-rearing, causing the parents to lay a second egg which they are allowed to raise. Brooding of chicks is nearly constant for the first two weeks after hatching, then shows a rapid decline in the next two weeks and ceases after about a month.

The young are covered with a grayish down until they are almost as large as their parents. They are able to fly after five to six months, but continue to roost and hunt with their parents until they turn two, at which point they are displaced by a new clutch. There is a well developed social structure within large groups of condors, with competition to determine a 'pecking order' by body language, competitive play behavior, and a wide variety of vocalizations. Adult condors will usually successfully defend their nests and offspring from predators such as bears, Common Ravens and Golden Eagles.

Conservation[edit]

California Condor's head.

At the time of human settlement of the Americas, the California Condor was widespread across North America. However, climate changes associated with the end of the last ice age and the extinction of the Pleistocene megafauna led to a subsequent reduction in range and population. Prehistorically, California Condors are known from Arizona [10], Nevada[11], New Mexico[12][13], and Texas[14].

In modern times, a wide variety of causes helped lead to the condor's decline. The condor's fickle mating habits and resulting low birth rate combined with a late age of sexual maturity make the bird vulnerable to loss of population. Significant damage to the condor population is also attributed to poaching, especially for museum specimens [15], lead poisoning (from eating animals containing lead shot), DDT poisoning[16], electric power lines, egg collecting, and habitat destruction. During the California Gold Rush, some condors were even kept as pets [17].

In addition to this, cattle ranchers observed condors feeding on the dead young of their cattle, and assumed that the birds killed the cattle - a fallacy which led to their extinction in some parts of the western United States. This belief was so deeply ingrained that the reintroduction of condors to the Grand Canyon was challenged in court by distant cattle ranchers, who had been taught by their parents that the bird was a predator of calves and lambs. This delayed their introduction until a court decision favorable to their reintroduction was reached.

As the condor's population continued to decline, discussion began about starting a captive breeding program for the condors. Opponents to this plan argued that the condors had the right to freedom, that capturing all of the condors would change the species' habits forever, and that the cost was too great. However, the project got the approval of the United States Government and the capture of the last wild condors began. The job was completed on Easter Sunday, 1987, when AC-9, the last wild condor, was captured[18]. There were only 22 condors left, all in captivity. The captive breeding program, led by the San Diego Wild Animal Park and Los Angeles Zoo, got off to a slow start due to the condor's mating habits. However, utilizing the bird's ability to double clutch, biologists began removing the first egg from the nest and raising it with puppets, allowing the parents to lay another egg. As the number of condors grew, attention began to focus on releasing some back into the wild. Condors were released in 1991 and 1992 in California, and again in 1996 in Arizona near the Grand Canyon[19] . Though the birth rate remains low in the wild, their numbers are increasing steadily through regular releases of captive-reared adolescents.

A Condor flying in the Grand Canyon, Arizona.

Unanticipated deaths among these populations occurred due to contact with Golden Eagles, power lines and other factors such as lead poisoning. Since 1994, captive-bred California Condors have been trained to avoid power lines and people. Since the implementation of this aversion conditioning program, only two condors have died as a result of contact with power lines. [2] Lead poisoning due to fragmented lead bullets in large game waste is a particularly big problem for condors due to their extremely strong digestive juices[20]; this lead waste is not as much of a problem for other avian scavengers such as the Turkey Vulture and Common Raven. This problem is expected to be addressed by a requirement that hunters use solid copper bullets when hunting in condor ranges.

In 2003 the first bird fledged in the wild since 1981. In March 2006, a pair of California Condors, released by Ventana Wildlife Society, attempted a nest in a hollowed out tree near Big Sur, California. This was the first time in more than 100 years in which a pair of California Condors had been seen nesting in Northern California. [3][4]

The 2005 population was about 273, including 127 in the wild[5].

According to biologists at the Zoological Society of San Diego, in early 2007, a California condor laid an egg in Mexico for the first time since at least the 1930s. If the chick hatches and survives, scientists hope it will herald the return of a breeding condor population to Mexico, decades after the species was wiped out there.

Relationship with Humans[edit]

A Chumash from the 1800s

Throughout its historic range, the California Condor has been a popular subject of mythology and an important symbol to Native Americans. Unusually, this bird takes on different roles in the storytelling of the different tribes.

The Wiyot tribe of California say that the condor recreated mankind after Above Old Man wiped humanity out with a flood [21]. However, other tribes, like California’s Mono, viewed 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 flood Ground 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 [22]. According to the Yokut tribe, the wings of the condor caused eclipses and sometimes he ate the moon, causing the lunar cycle [23]. The Chumash tribe of Southern California believed that the condor was once a white bird, but it turned black when it flew too close to a fire [24].


The condor was a very important bird to the Native Americans. Condor bones have been found in Native American graves, as have condor feather headdresses. Cave paintings of condors have also been discovered [25]. Some tribes ritualistically killed condors to make ceremonial clothing out of their feathers. Shamans then danced while wearing these to reach the upper and lower spiritual worlds. Whenever a shaman died, his clothes were said to be cursed [26].

However, some scientists, such as Noel Snyder, believe this process helped contribute to the condor’s decline [27]. If so, this would be the only species that was endangered by the California natives.

References[edit]

  1. ^ Fisher, Harvey L. (1944): The skulls of the Cathartid vultures. Condor 46(6): 272-296. PDF fulltext
  2. ^ Howard, Hildegarde (1947): A preliminary survey of trends in avian evolution from Pleistocene to recent time. Condor 49(1): 10-13. PDF fulltext
  3. ^ Howard, Hildegarde (1962): Bird Remains from a Prehistoric Cave Deposit in Grant County, New Mexico. Condor 64(3): 241-242.
  4. ^ Nielson, J.: "Condor", page 27. Harper Perennial, 2006
  5. ^ BirdLife International (2006). Gymnogyps californianus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 4 September 2006. Database entry includes justification for why this species is critically endangered.
  6. ^ Nielson, J.: "Condor", page 1. Harper Perennial, 2006
  7. ^ BirdLife International (2006). Gymnogyps californianus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 4 September 2006. Database entry includes justification for why this species is critically endangered.
  8. ^ BirdLife International (2006). Gymnogyps californianus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 4 September 2006. Database entry includes justification for why this species is critically endangered.
  9. ^ Nielson, J.: "Condor", page 58. Harper Perennial, 2006
  10. ^ Miller, Loye (1960): Condor Remains from Rampart Cave, Arizona. Condor 62(1): 70 PDF fulltext
  11. ^ Miller, Loye (1931): The California Condor in Nevada. Condor 33(1): 32. PDF fulltext
  12. ^ Wetmore, Alexander (1931): The California Condor in New Mexico. Condor 33(2): 76-77. PDF fulltext
  13. ^ Wetmore, Alexander (1932): Additional Records of Birds from Cavern Deposits in New Mexico. Condor 34(3): 141-142. PDF fulltext
  14. ^ Wetmore, Alexander & Friedmann, Herbert (1938): The California Condor in Texas. Condor 35(1): 37-38 PDF fulltext
  15. ^ Nielson, J.: "Condor", page 83. Harper Perennial, 2006
  16. ^ Kiff, L. F.; Peakall, D. B. & Wilbur, S. R. (1979): Recent Changes in California Condor Eggshells. Condor 81(2): 166-172. PDF fulltext
  17. ^ Nielson, J.: "Condor", page 88. Harper Perennial, 2006
  18. ^ Nielson, J.: "Condor", page 24. Harper Perennial, 2006
  19. ^ BirdLife International (2006). Gymnogyps californianus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 4 September 2006. Database entry includes justification for why this species is critically endangered.
  20. ^ Thacker, Paul D. (2006): Condors are shot full of lead. Environmental Science & Technology 40(19): 5826. HTML fulltext
  21. ^ Nielson, J.: "Condor", page 37. Harper Perennial, 2006
  22. ^ Nielson, J.: "Condor", page 38. Harper Perennial, 2006
  23. ^ Nielson, J.: "Condor", page 40. Harper Perennial, 2006
  24. ^ Nielson, J.: "Condor", page 40. Harper Perennial, 2006
  25. ^ Nielson, J.: "Condor", page 36. Harper Perennial, 2006
  26. ^ Nielson, J.: "Condor", page 41. Harper Perennial, 2006
  27. ^ Nielson, J.: "Condor", page 41. Harper Perennial, 2006


Cited Texts[edit]

  • Lesson, René-Primevère (1842): [Description of genus Gymnogyps]. L'Echo du monde savant ser. 2 6(44): col. 1037.
  • Nielsen, John. Condor: To the Brink and Back- The Life and Times of One Giant Bird. New York: Harper Perrenial, 2006.


External links[edit]