, Research Paper
Lorin McNulty McNulty 1
Environmental Biology
Biology Mid-Term
10 April 2000
THE STRUGGLE FOR THE CALIFORNIA CONDOR
The natural environment of the modern world has been under siege for the better part of the past century. This has been due to many factors. The waste produced by an ever-expanding human population has tainted much of the natural resources available to both humans and animals alike. Efforts to curb this waste output and to more effectively dispose of the waste have failed in the mainstream. The constant change of the common environment instituted by humans who have collectively sought to modify their own habitat has exacted a high toll on the available habitat for lesser creatures. Constant waste production, poor disposal, and habitat encroachment have combined to render the balance of the natural world asunder. ?The delicate and intricate balance of the natural world has been damaged by a dominant species that has commonly disregarded its inherent responsibility to garnish its actions concurrent with the world it shares with the rest of nature? (Center for Reproduction of Endangered Species. p3).
An all too common result of this imbalance is the expiration of entire species of animals that are dependent on precious resources. Historically, the presence of humans
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has exponentially accelerated the natural rate at which fringe species have met with extinction. Modern humans have followed their own ancient precedent in this regard. ?Recorded evidence of early human settlement has shown that human presence alone had accelerated extinction rates to several times its natural rate? (Center for the Reproduction of Endangered Species. p4).
However, it is a different precedent that modern humans have sought with the advent of a new and more complete awareness of our collective role as the dominant species. Several recent advances in waste treatment are offering alternatives to the usual high-output, wasteful societal paradigm. Although habitat encroachment continues to be a source of great conflict between the human population and the animal world, the human race has begun in earnest to attempt restoration of some species that have fallen casualty to pollution, encroachment, or both. Although success has been limited, these restorative efforts represent a reckoning on the behalf of humans with their place in the natural order.
One of the most successful of these programs concerns the California Condor. This magnificent species had all but disappeared from its natural range due to the human presence. With the recently recorded demise of the California Condor?s natural population came the effort to repopulate selected areas of habitat with captively breed condors.
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THE STUDY OF THE CALIFORNIA CONDOR
The California Condor is a remarkable species of scavenging birds indigenous primarily to California. Early studies showed populations of condors ranging from the rocky coastal areas to the interior mountains. In the early 1900s, sightings of these majestic birds, although reclusive in nature, were commonplace.
Early in the 1900s, serious scientific studies began on the California Condors. There were many successful studies in the wild, and there was increasing interest from the scientific community. In 1939, the naturalist Carl Koford first began a careful scientific study of these condors in the wild. Carefully documented field studies yielded a wealth of information about a species in the American West that had previously eluded the scientific eye. One development resulting from the study of Carl Koford was the establishment of the exact nature of the diet of these birds. Although known to be primarily scavengers, it was learned just how well adapted these birds are at finding and discriminating suitable prey. It was learned that the primary feeding times were during daylight hours, with most activity centering near noon. They were observed feeding on carcasses in all states of decay, and even competing with other more aggressive species for rights to a kill. Their bills are exquisitely adapted to tearing animal flesh, and their digestive systems are specially suited to digesting rotting flesh. Condors were not known to have attacked live prey, and the diet of condors was found to have been an assortment
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of carcasses found throughout the feeding range. ?Condors were found to have spent an average of fifteen hours a day at the roosting site, and even more hours on days of inclement weather? (Grossman. p38).
These studies also produced the first scientific measure of the social structure of these birds. Their population had come under suspicion during this time, and the population count during this time seemed to prove their decline. The territories of these birds were found to be wide stretching, often including several hundred miles. The ability of these birds to roam these territories in search of food was found to be incredible, with some specimens gliding on large wings as far as ten miles with no wing movement. Poor weather and still air had been found to restrict the birds to the nesting site. In optimum conditions, making use of thermal updrafts for efficient flying was found to be common among these birds. This mobility was shown to provide another advantage with the remains of coastal marine molluscs found near some nesting sites during the study. In combination with the diet of these birds, this mobility led to conflict with the ranching efforts of humans. Many ranchers began making a misguided effort to protect their livestock by regularly shooting condors even though condors are scavengers, and are not hunters of live prey. Further, sport shooting went largely unregulated for years.
Some other developments included establishing the nature of the reproductive biology of the condors. These birds were observed as cavity dwellers. ?Nesting in rocky caves, crevices, or among boulder formations, these condors were found to move to new sites between nesting attempts? (The Encyclopedia of Birds). This was deemed to be part
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of the habitat needs these birds required. The incubation period of these birds was found to be fifty-four to fifty-eight days, with each parent taking turns guarding the nest. The fragility of these birds was attributed in part to their low birth rate. ?A mature female will lay one egg only every two years, and the young are fed throughout most of their eighteen to twenty month adolescence. Although a chic begins flight practice at five to six months of age, the dependency on the adults for food can continue into the second year? (Audubon?s Birds of America.). This reproductive profile rendered the condor population sensitive to hunting and encroachment because they required so long a period of time to regenerate losses in population. ?The effects of industrial chemical pollution further complicated regeneration of losses. Industrial chemical pollution has been proven to be destructive with studies having shown that the eggshells of condors were reduced in thickness by as much as thirty percent after the widespread use of DDT? (MacMillan Illustrated Encyclopedia of Birds).
CONSERVATION EFFORTS FOR THE CALIFORNIA CONDOR
With the knowledge gained from successful field studies, scientists began to consider solutions to the dwindling wild population of California Condors. Captive breeding was an idea that garnished considerable attention from the general scientific
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community. Two scientists from the San Diego Zoo proposed a captive-breeding program aimed specifically at regenerating the wild population of California Condors. The San Diego Zoo Director Belle Benchley and Curator K.C. Lint had met with considerable success with a captive breeding program aimed at breeding Andean Condors through a technique known as double clutching. This involved removing eggs from captive breeding pairs, thereby stimulating the female to lay one egg every year. The doubled egg laying rate offered potential for regeneration of numbers faster than a naturally breeding pair. Pressure from environmental groups eventually prevented the proposed program from going into action with the overriding concern being disturbance of the remaining pairs in the wild.
The attention devoted to the preservation of the California Condor experienced a resurgence in nineteen sixty-six when the California Condor appeared on the first published list of endangered species. The population estimates ranged from fifty to sixty birds.
The population continued to decline and in nineteen seventy-nine estimates ranged from twenty-five to thirt
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captive pairs to regenerate the species. The Condor Research Center was granted license to attempt deliberate placement clutching or condor pairs to aid in a captive-breeding program.
Several years passed with continuing efforts to begin captive breeding resulting in the first captive hatch in March of nineteen eighty-three. By this time, the wild population was estimated to be nineteen birds. By nineteen eighty-five, this continued decline of the wild breeding population coupled with the initial captive breeding success resulted in approval of a plan to capture the remaining wild birds for captive breeding. The remaining nine wild birds were captured, and the breeding program expanded.
Eventually, artificial incubation began as part of the regeneration effort. The artificially incubated eggs hatched at nearly twice the rate of eggs studied in the wild. This high success rate lent further credence to the once controversial intervention in the name of species regeneration.
The proper care of the captive birds was the purpose behind the design of the captive breeding facility. The first facility was called the Condorminium, and was designed as an enclosure that would allow the most natural setting possible. This was concurrent with the final goal of reintroduction. The facilities used for this captive-breeding program were designed to allow limited flapping and mobility for the birds, thus mitigating the stress of captivity. Constructed in an area of access to wind and some weather, these enclosures helped to preserve some sense of instinct. To further maintain a healthy environment, the enclosures were strictly off limits to the public. Enclosures used
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in this program were installed in several regions of the American West, with pairs being raised in San Diego, Boise, and eventually Los Angeles.
The success of this program was to be measured by the release of breeding pairs of condors that were bread in captivity. There were several problems to be addressed in this process. One question was how to ensure that the condors to be released would have the benefit of human aversion. Minimizing human contact during the rearing stage was one measure stipulated in the program outline. Negative reinforcement training was widely used to condition captive birds with the skills needed to succeed in the wild. Aversion training was also used in an attempt to preclude accidental injuries after release. The natural curiosity of condors can lead wild condors near population centers, often to perch on power lines. Aversion training aimed at preventing such roosting can include presenting captive birds with a combination of trees and mock telephone poles to perch on. If the birds choose to perch on the mock poles rather than on the available trees, they are provided negative reinforcement by way of a mild shock. These techniques are in place to afford captive birds every opportunity for success upon release.
The release program continued to grow, with multiple pairs gaining release between nineteen ninety-three and nineteen ninety-seven. The first release site was in the Los Padres National Forest in southern California. There were two separate release points constructed there in response to an increase in human activity and power lines. There was a second release point used in Lion Canyon, which is also in the Los Padres National Forest. Subsequently, a site thirty miles north of the Grand Canyon called Vermillion
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Cliffs was chosen as a release site because of its unique landscape and remote location. The success of the released condors has proven encouraging. There are four areas now populated by released breeding pairs, and future releases are planned at regular intervals. Maintenance of released birds includes baiting designated feeding areas with carcasses to encourage the birds to learn to scavenge. This requires regular placement of food with careful avoidance of any human contact in order to help preserve the bird?s natural searching instinct. Many questions remain about the future of these birds, but the regeneration of the wild population continues to benefit from the captive breeding programs.
LIMITATIONS OF CONDOR CAPTIVE BREEDING
Captive breeding programs represent a concerted effort on behalf of humans to sustain the species that have been gravely affected by the changes in environment bought about by the actions of mankind. Many people accept programs such as these as progress toward mending the damage inflicted by humans on the environment. There are, however, several fundamental questions that are going unanswered.
First, does answering the slow regeneration problem through captive double clutching fix the problem of extinction or simply delay a symptom? It is important to recognize that the numbers of wild condors were diminished to the point of near extinction as a result of human destruction of habitat. Through pollution and
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encroachment, humans have permanently changed the environment. Slowing this rate of change is central to any solution if we are to attempt to reach equilibrium with nature.
Second, can the collective actions of the human race be changed sufficiently for the continued survival of fringe species? Evidence has shown that conflict between fragile species and the agricultural settlement of common habitat inevitably leads to the decimation of the species in question, in this case the California Condor. The solution to this element of the problem is perhaps the most elusive. This cannot be answered by resettlement or repopulation. The actions of the human race must become responsible on the individual level. Education about endangered species and federal protection of endangered species can help, but the questionable future of fragile species can be made more certain only by responsible actions on the part of individuals. Additionally, can humans share common land with wild scavengers with out justification for needless hunting? Many people do not see why humans should try to share resources with a competing species.
This leads to perhaps the most central question concerning conservation in general. Why conserve? Many average people fail to see the fault in the actions of humans as the dominant species on the planet when annihilate subordinate species. If there exists a conflict between human interests and the needs of a competing species, then why accommodate a lesser-developed animal? The answer can only be found in the idea that humans have a responsibility to preserve the natural order. Perhaps best answered by
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a Park Ranger with whom I had the opportunity to speak about this very issue, ?saving weak species may seem like a waste of time to some people, but as soon as we give up on a single species, we have started down the wrong path?. Humans, as a race, benefit from natural preservation in the projected future. Long term preservation of natural resources, plant, mineral, and animal alike, is an idea that holds little merit with a majority of humans who are often faced with more immediate concerns for their own well being and welfare. Balancing immediate needs and long term interests is one challenge facing the human race as resources become more scarce and human needs grow with our population. If we are to collectively survive as members of an intricate ecosystem, we must learn to manage our natural dominance toward the good of the planet.
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?New World Vultures.? Macmillan Illustrated Animal Encyclopedia. 1984 ed. p216
?Condors and Vultures.? Audubon?s Birds of America. CrossRiver Press, 1981. p89
Grossman, Mary Louise. Birds of Prey of the World. Clarkson N. Potter, 1964. p37-39, 203-204.
?Birds of Prey- The Raptors.? The Encyclopedia of Birds. 1985 ed. p103-104
?California Condor Conservation Efforts.? Center for Reproduction of Endangered Species. 1 April 2000. pp1-5. San Diego Zoo. 8 April 2000. *http://www.sandiegozoo.org/cres/milestone.html*.
?Condor Reproductive Biology.? Center for Reproduction of Endangered Species. 1 April 2000. pp 1-4. San Diego Zoo. 7 April 2000. *http://www.sandiegozoo.org/cres/reproductive.html*