This species was present in a number of western states prior to the early 19th century, ranging from British Columbia to Baja California, and throughout the west. Lewis and Clark found them on their famous expedition through the Northwest. Early explorers and settlers in Arizona, Utah, Colorado, Wyoming, Idaho, Montana, Alberta and Baja California also reported condors in the early 1800's. There are few estimates of the size of the original wild condor population prior to the arrival of European settlers. By 1950, however, the population had been reduced to about 150 birds, and its range had been restricted to southern California exclusively.
Not considered a habitat specialist, the California Condor soars far and wide in search of carrion. Traditionally, it has been found from beaches to high mountainous areas and at many points in between. It mainly requires wide-open areas where food can be found. Most nesting takes place on cliffs.
Expending very little energy, these scavengers soar on thermal updrafts and wind currents until they spot potential food sources. Not endowed with the acute sense of smell of the Turkey Vulture, it is believed that the condor finds most of its food by observing other scavengers, such as the Turkey Vulture, Common Raven, and Golden Eagle. When they arrive at a carcass, the sheer size of condors generally guarantees the departure of other scavengers, but Golden Eagles (equipped with powerful talons) often remain and compete for food. Domesticated animals (cattle, sheep etc.) make up a large part of the condor's diet, though mule deer and feral pigs killed by hunters are also food sources. In the past, condors were noted feeding upon marine mammal carcasses (whales, sea lions etc.) along the Pacific Coast; this habit has resumed with the flock at Big Sur, California. Condors will often eat small bones in order to gain calcium. Unfortunately, this habit can lead condors to ingest a variety of manmade objects that are confused with bones.
Wild California Condors are monogamous and will stay with their breeding partner for years, if not for life. Courtship includes aerial displays by both sexes and joint visits to potential nest sites within their territory. Research suggests that female condors pick one nest site from several potential areas visited during courtship. Nest sites are usually located on ledges or in caves, but one California pair has been observed nesting in a burned-out section of a giant sequoia tree. No actual nest is built, though a ring of debris may be accumulated from whatever materials are available near the egg. The female only lays one egg. (Condor eggs resemble chicken eggs, but – at 4.5 inches – are considerably larger). Once the egg is laid, both parents incubate it for nearly 60 days. Single shifts at the nest can last several days. Newly hatched chicks are well developed and covered in a yellow-orange down. The condor chick will not reach full adult-like size for up to four months and will not fledge from the nest site for half a year. Once fledged, the young condor remains dependent upon its parents throughout its entire first year of life.
California Condors may wander in search of food, but distinct populations are non-migratory. All past populations were thought to be non-migratory as well.