California condor

Appearance

The plumage 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 wingspan is the widest of any North American bird, and its weight of up to 12 kg nearly equals that of the trumpeter swan, the heaviest among native North American bird species. The condor is a scavenger and eats large amounts of carrion. It is one of the world's longest-living birds, with a lifespan of up to 60 years.

The adult California condor is a uniform black with the exception of large triangular patches or bands of white on the underside of the wings. It has gray legs and feet, an ivory-colored bill, a frill of black feathers surrounding the base of the neck, and brownish red eyes. 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 its flight feathers.

The condor's head and neck have few feathers, and the skin of the head and neck is capable of flushing noticeably in response to emotional state, a capability that can serve as communication between individuals. The skin color varies from yellowish to a glowing reddish-orange. The birds do not have true syringeal vocalizations. They can make a few hissing or grunting sounds only heard when very close.

Contrary to the usual rule among true birds of prey, the female is slightly smaller than the male. Overall length can range from 109 to 140 cm and wingspan from 2.49 to 3 m. Their weight can range from 7 to 14.1 kg, with estimations of average weight ranging from 8 to 9 kg.

Wingspans of up to 3.4 m have been reported but no wingspan over 3.05 m has been verified. 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 largest wingspan of any North American bird. They are surpassed in both body length and weight only by the trumpeter swan and the introduced mute swan. The American white pelican and whooping 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 they are mistaken for other species of bird.

The middle toe of the California condor's foot 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 than gripping. This is more similar to their supposed relatives the storks than to birds of prey and Old World vultures, which use their feet as weapons or organs of prehension.

Status

The California condor conservation project may be one of the most expensive species conservation projects in United States history, costing over $35 million, including $20 million in federal and state funding, since World War II. As of 2007 the annual cost for the condor conservation program was around $2.0 million per year.

Behavior

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 have been known to fly up to speeds of 90 km/h and as high as 4,600 m. 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 thermals to aid them in keeping aloft.

The California condor has a long life span, reaching up to 60 years. If it survives to adulthood, the condor has few natural threats other than humans.

Because they lack a syrinx, their vocal display is limited to grunts and hisses. Condors bathe frequently and can spend hours a day preening their feathers. Condors also perform urohidrosis, or defecate on their legs, to reduce their body temperature.

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.

Habitat

The condors live in rocky shrubland, coniferous forests, and oak savannas. 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 in search of carrion.

Reproduction

Condors begin to look for a mate when they reach sexual maturity at the age of six. 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. 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-white egg every other year.

Eggs are laid as early as January to as late as April. The egg weighs about 280 grams and measures from 90 to 120 mm in length and about 67 mm 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.

The eggs hatch after 53 to 60 days of incubation by both parents. Chicks are born with their eyes open and sometimes can take up to a week to leave the shell completely. 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 forage with their parents until they are in their second year, at which point the parents typically turn their energies to a new nest.

Food

Wild condors maintain a large home range, often traveling 250 km a day in search of carrion.

It is thought that in the early days of its existence as a species, the California condor lived off 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, donkeys, horses, pigs, cougars, bears, or cattle.

Alternatively, they may feed on the bodies of smaller mammals, such as rabbits or coyotes, aquatic mammals such as whales and California sea lions, or salmon. Bird and reptile carcasses are rarely eaten.

Since they do not have a sense of smell, they spot these corpses by looking for other scavengers, like eagles and smaller vultures, 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, and golden eagles, which will fight a condor over a kill or a carcass. In the wild they are intermittent eaters, often going for between a few days to two weeks without eating, then gorging themselves on 1–1.5 kilograms of meat at once.

Predators

Ravens are the main predatory threat to condor eggs, while golden eagles and bears are potential predators of condor offspring.