James Buono, Steph DiPreta and Tyler Smith
Biology 101
The California condor, scientific name Gymnogyps californianus, is a bird that used to dominate over the skies forty thousand years ago when the mammoth used to still be around. Due to the ignorance and carelessness of people, it has been pushed to near extinction(Derrickson et al 2010). The Condors were deemed endangered in 1974 (Chang et al 2006).Until the hard work of the United States government, the San Diego and Los Angeles Zoo pushed to put them back in the skies(Schorch 1991).
The California condor weighs seventeen to twenty five pounds and has a wingspan longer than the height of any human being roughly nine and a half feet and standing a height of about fifty five inches. It is the largest flying bird in North America and can fly at speeds up to 100 miles per hour and can soar up to 15,000 feet but normally stay at an elevation of around four thousand feet(Moir 2006). The condor has a black body, a grey neck and shades of yellow red and orange on its head. They eat dead animals including rabbits, rodents, sheep, deer and even cows. The condors are scavengers that now travel through California, Mexico and Arizona living up to sixty years, the condor used to live throughout North America(Nielsen 2006). They do not usually breed before 8 years of age, and teh populaiton sustainability requires an annual adult survival rate of 90% to 95% (Aguilar et al 2009).
During the late 1800’s life became very difficult for the California condor. With people moving to the west coast to the California condor’s habitat they began shooting the bird in most cases just for fun; ranchers also shot the birds to protect their cattle and livestock. However, the condors were also eating poisoned meat and began dying. In the mid-1940’s farmers began using a new pesticide called DDT, when the birds would eat food contaminated with DDT the chemicals would accumulate in their bodies, and when they would produce eggs, the eggs would be so fragile that when they were set on for incubation they would quickly break. Although the use of DDT was banned in 1974 the traces of the substance were still left in the environment the condor lived in which further diminished the species. By the 1940’s the population was increasingly smaller with an estimate of about 150, as the condor became more “rare”, museums and collectors paid large amounts money for condors and there eggs(Goldish 2009).
Lead poisoning also contributed to the death of California condors. The condors were scavengers and when a hunter would kill an animal, he would kill it with a lead bullet and when the condors would go to eat the carcass they would often eat the bullet as well and when they ate the bullet they would get lead poisoning that would slowly kill them(Goldish 2009)(Aguilar 2009). Another contributor to the death of the California condors is the West Nile virus. The virus has infected and killed at least 35 species of mammals and 334 species of birds, some of whom carcasses the condors feed on(Chang et al 2006). There were many different mortality agents that contributed to the endangerment of the California condor. Besides lead poisoning, DDt and west nile virus, there were power collisions, drowning, and predator control poisoning (Bloom et al 1998).
The two poisons especially didn’t help breeding patterns since condors mate for life and if there mate dies from poisoning they do not find another partner and no more babies will be produced from the condor. The male will “dance” in front of the female in late fall to persuade her to become his mate. Only when she is well within the breeding season will she allow the male condor to mate with her, this normally happens around December or January when they also find a nesting spot, this is normally a place safe from predators like a small hole in a cliff just large enough for both condors.