Bred to soar: despite setbacks, captive-hatched California condors are now surviving at a higher rate when released into the wild.
Number 59 was one of three captive-hatched California condors released to the wild a few days earlier in the Sierra de San Pedro Martir. Before the birds could adjust to their new freedom and unfamiliar territory, however, two were attacked in the air by golden eagles, a not uncommon danger for condors. Number 59 retreated to the safety of trees in the heavily forested mountainside. The few times the frightened bird ventured out he napped low through the trees, a very uncondor-like behavior. Today, after the dramatic rescue and successful second release on Baja six months later, Number 59 symbolizes both the achievements and problems of reintroducing endangered California condors to the wild. It also symbolizes the personal commitment of researchers like Wallace to the survival of condors. "I've been working with condors since 1980," says Wallace, a wildlife specialist at the San Diego Zoo and leader of the California condor recovery team since 1992. "I never thought I would be doing condors for so long. I have a lot invested in this species."
Once on the brink of extinction, there are now more California condors both in the wild and in captivity in at least a hall" century. Indeed, captive condors are now so numerous they are housed in four separate breeding facilities in the United States. Some of their offspring fly free at roar release sites in two U.S. states and one in Mexico. Reintroduced condors have even begum to breed and find food on their own in the wild.
Despite these successes, the effort to save California condors continues to have problems, evoke criticisms, and generate controversy. Captive-hatched condors released to the wild have died at what to stone people are alarmingly high rates. Others have had to be recaptured after they acted foolishly or became ill. As a result, the scientists, zookeepers, and conservationist who are concerned about condors have bickered among themselves over the best ways to rear and release the birds.
At first glance, why anyone would want to save California condors is not entirely clear. Unlike the closely related Andean condors with their white neck fluff or king vultures with brilliant black-and-white coloring, California condors are not much to see. Their dull black color--even when contrasted with white underwings-featherless head and neck, oversized feet, and blunt talons are hardly signs of beauty or strength. Nor have the condors' carrion-eating habits endeared them to many people.
Their appeal begins to become evident when they take flight. With nine-and-a-half-foot wingspans and weights up to twenty-eight pounds, California condors are North America's largest fully flighted birds. In the Americas, only Andean condors are bigger. California condors can soar almost effortlessly for hours, often covering hundreds of miles a day. Only occasionally do they need to flap their wings to take off, change direction, or find a band of warm air known as a thermal to carry them higher.
In prehistoric times, California condors ranged from southern British Columbia in Canada to northern Baja and east across the southern United States to Florida and New York. By the time Europeans arrived, condors were limited to the mountains along the Pacific coast. Perhaps a hundred or more remained by the 1940s, all confined to a U-shaped region in the mountains and foothills north of Los Angeles. By the early 1980s, they numbered only twenty-one.
No one knows for sure why California condors almost disappeared. Probably never numerous anywhere, condors may have begun declining when large Ice Age mammals like mammoths and giant ground sloths, on whose carcasses they once fed, became extinct. Early European explorers and settlers, however, reported often seeing eighty or more condors gathered at a carcass, a sign of a healthy population. More recently, condors were sometimes shot by hunters or poisoned by ranchers who mistakenly thought they killed livestock. Condors also died after eating deer and other animals killed by hunters who had used lead bullets or shot. Ingested lead, a problem that went unrecognized until the mid 1980s, can kill condors and other birds if untreated.
Whatever the reasons, the U.S Fish and Wildlife Service, along with several private groups, launched a major effort to study and save the birds in the early 1980s. The effort was based on earlier research and land-acquisition programs. In addition to monitoring condors in the wild, captive-breeding programs were started at the San Diego Wild Animal Park and the Los Angeles Zoo with eggs and chicks taken from their nests. When six of the last fifteen wild condors died or disappeared in 1984-85, FWS officials decided to capture the remaining birds. In 1987, with the population numbering twenty-seven, the last wild California condor was brought into captivity.
From the beginning, scientists and zookeepers sought to increase condor numbers quickly to preserve as much of the species' genetic diversity as possible. From studying wild condors, they already knew that if a pair lost an egg, the birds would often produce another. So, the first and sometimes second eggs laid by each female in captivity were removed, artificially incubated, and the chicks raised using handheld puppets made to look like adult condors.
Such techniques worked. Beginning will the first chick conceived and hatched in captivity in 1988, 314 California condors have been hatched at the San Diego and Los Angeles zoos and, later, the World Center for Birds of Prey in Boise, Idaho. More than 90 percent survived. The total condor population now numbers 247. That includes 148 birds in the three breeding centers and a new one opened by the Oregon Zoo in Portland in 2003.
As captive numbers rose and worries about the species' survival diminished, the scientists and zookeepers began releasing condors to the wild, at first female Andeans to test methods in 1988 and then California condors in 1992. With the Andeans recaptured, the first releases took place in Los Padres National Forest in Southern California, northwest of Los Angeles. Later, birds were released in Cite Ventana Wilderness Area further north in California, along the Vermilion Cliffs just north of the Grand Canyon in Arizona, and in Baja. The most recent release occurred in Pinnacles National Monument in California last January. In all, 174 California condors have been released since 1992, of which 97 remain in the wild today.
From the outset, however, problems arose. The released condors engaged in some reckless and even dangerous behaviors. Some landed on people's houses and garages, walked across roads and airport runways, sauntered into park visitor centers and fast food restaurants, and took food offered by picnickers and fishermen. None are known to have died by doing so, though. More seriously, one condor died from drinking what was probably antifreeze. Others died in collisions with overhead electrical transmission wires, drowned in natural pools of water, or were killed by golden eagles and coyotes. Still others were shot by hunters and killed or made seriously ill from lead poisoning. Some just plain disappeared.
Most recently, in 2002 and 2003, some of the first chicks hatched in the wild--in itself a major milestone for the condor program died after their parents fed them bottle caps, glass shards, pieces of plastic, and other man-made objects that fatally perforated or blocked their intestines. These deaths may be due to the chicks' parents mistaking man-made objects for bone chips eaten for their calcium content. "We may have to feed them bone chips ourselves," Wallace says, "in order to encourage them away from the man-made material."
Those losses have led some former participants in the California condor recovery project to question how rite birds are raised and released to the wild. 'Tin concerned that we have not created a self-sustaining operation," says David Clendenen, a former condor field biologist, who now manages the Wind Wolves Preserve in California.
"Mortality rates are too high," adds Vicky Meretsky, associate professor of conservation biology at Indiana University in Bloomington. Meretsky says death rates above 10 percent a year cannot be sustained by a wild condor population alone. The current rate stands at 14-15 percent and earlier reached 20 percent, Wallace says. In fact, more than one-third of all released condors have either died or been returned to captivity, usually within the first two years. "We have an ethical responsibility to fix the problems and not reenact them," Meretsky states.
Clendenen, Meretsky, and others have advocated pulling most if not all released condors out of the wild and replacing them with younger birds that have been hatched and raised by their parents in natural enclosures located in or near the areas where they will be released rather than in urban zoos. The critics argue that puppet-raised condors are too tame and do not know how to be wild condors. "They are caricatures," Clendenen says. The critics also accuse the U.S. Fish and Wildlife Service of doing too little to reduce lead poisoning.
Mike Wallace disagrees. He argues that the condors' problems in the wild have more to do with their immaturity, inexperience and, most importantly, lack of proper socialization. There are only slight differences in behavior and survival rates between puppet and parent-raised condors in the wild, according to Wallace. Further, because all the birds released to the wild before 1995 were brought back to the zoos, most wild condors are still juveniles or, as Wallace once described them, "goofy teenagers." They engage in more dangerous behaviors than the older birds. Only recently have some condors become mature and started breeding.
Additionally, Wallace says, some of the condors' problems represent natural behaviors that help them survive as carrion caters. For one, the highly social condors are naturally' curious. They watch each other and other scavengers, mid follow them to food. In that sense, people are just another food source worth following. Also, the propensity of released California condors to hang around people is not much different from wild Andean condors in South America. Andeans often land near campers and solicit food. Maybe from the air they think the shiny aluminum tops and hubcaps of their vehicles are water.
Further, most captive-hatched birds released to the wild suffer high mortality rates, adds Lloyd Kiff, a former condor recovery team leader who is now science director for the Peregrine Fund. The Peregrine Fund manages the Boise, Idaho, condor-breeding center and the Arizona release site. "A lot of [other] birds are killed when they hit power birds or houses," Kiff says. "A lot of birds hang around people and human structures in hopes of getting food. But no one notices or comments because the birds are not rare."
The real key to successful condor reintroduction, Wallace believes, lies in properly socializing young condors as members of a group that follow and learn from older, preferably adult birds. That, he argues, was missing from earlier condor releases to the wild. Typically, condors hatched in the spring were released to the wild that fall or winter, when they were still less than a year old. Especially in the early releases, the young condors had no adults or even older juveniles to learn from and keep them in their place. Instead, the only oilier condors they saw in captivity and the wild were ones their oval age.
Now, condor chicks at the San Diego and Los Angeles zoos are raised in cave like nest boxes. The chicks can see older condors in a large flight pen outside their box but cannot interact with them until they are about five months old. Then, the chicks are gradually released into the pen and the company of the social group. The group includes adult and older juvenile condors that act as mentors for younger ones. "Adults provide leadership and direction on a basic social level," Wallace says. "We want chicks to want to be part of the group, not buddies with similar aged chicks that do not, know anything."
In the presence of older birds, the younger condors tend to be shy and sub missive. As they get older and move up the social scale, they learn to be more cautious in their" actions for fear of being attacked by the adults, says Michael Clark, the Los Angeles Zoo's condor keeper and coauthor with Wallace on the new puppet-rearing technique. And more tentative chicks are less likely to get into trouble when released to the wild.
That brings us to Sierra de San Pedro Martir. At more than ten thousand feet elevation, it is the Baja Peninsula's tallest peak. The mountain's higher elevations where the condors were released feature tall pines, spruces, and hemlocks as well as manzanita, a low-growing shrub with smooth, red bark. The ground is littered with large granite boulders. A fifteen mile-long ridge overlooks deep canyons with ledges for nesting that double as condor launch pads for takeoff.
The lower elevations are dotted with yuccas, agaves, pitahaya cacti, and other Sonoran Desert plants. Ranches farther down the mountain have plenty of dead livestock for condors to eat. And there are few people or buildings in the area for condors to visit. Scientists have studied Baja as a possible release site since the 1970s. "We Would like to get condors back in as much of their former range as possible," Wallace says. "This is the southernmost part of their range. It was time."
More than just time, releasing California condors in the fifteen thousand-acre Sierra de Seat Pedro Martir National Park is seen by some conservationists as key to preserving northern Baja's natural environment. "The condors make this park more attractive," says Horatio de la Cueva, a wildlife biologist at the Center for Scientific Investigation and Education (CICESE) in Ensenada. "This is an under explored area of Baja. The condors will be a focal point for scientific studies. They are a spectacular bird that people want to see and be associated with."
Beyond Baja, the condors have an international importance as well. "Mexico has provided wolves, black ears and jaguarundis to help restore endangered species in the United States," says Ezequiel Ezcurra, president of Mexico's National Institute of Ecology. "Now we are the recipients of an endangered species from the United States. Both countries need to cooperate to bring the condor back."
For Wallace, the release of California condors in Baja--five in the spring of 2003 and another six in the fall--was an experiment designed to test his theories. The original shipment of condors included a sixth bird not intended for release--Xewe, a then eight year-old female. Her presence and calming personality provides a role model for the younger condors, even when they are outside the release pen and she is inside. Also, the released birds were older than most previously released condors, all having spent two years with socializing groups in the San Diego and Los Angeles zoos.
Nevertheless, the experiment might have ended before it had gotten under way. A fire broke out in the mountain's lower elevations that July, just two months after the first group of condors was re released. Wallace suspects it was set deliberately "to get rid of us." The fire raced up the mountain, getting within "a stone or two's throw," he says, of the condor bolding pen and the monitoring team's campsite. Wallace and his staff moved the birds arm equipment to safer ground, bulldozed firebreaks, and put out fires that jumped the breaks. Finally, after nearly two weeks battling the blaze, rains helped project and park staff, Mexican soldiers, and volunteers from Mexico's world-class National Observatory farther up the mountain beat the fire back. The only injury: One observatory staffer, obviously inure experienced in dealing with stars than live birds, got bit on the hand while holding one of the condors during the frenzied evacuation.
Unfortunately, fire has not been the Baja condor project's only problem. Sluggish economies in the United States and Mexico have limited the ability of government agencies, supporting institutions, and private donors to fond the project properly. Two of the four Mexican field biologists whom Wallace hired to monitor the birds left when they were not paid. Wallace has also bad to deal with suspicious Mexican ranchers and campesinos who aren't quite sure what the biologists are doing.
So far, though, Baja's released condors seem oblivious to such problems. The condors, even Number 59, have learned not only to stay away from the golden eagles' nests, but also to dominate the smaller birds. They have avoided people as they explore the Sierra de San Pedro Martir and surrounding mountains. And they have followed eagles, turkey vultures, and other scavengers to food.
Elsewhere, released condors in California and Arizona are making longer and longer flights, sometimes staying away for weeks and months at a time. The Ventana and Los Padres National Purest condors have traveled more than a hundred miles back and forth between their release sites. One Arizona condor flew more than three hundred miles north following the Colorado and Green rivers to Flaming Gorge National Recreation Area in southwestern Wyoming before returning. Other Arizona condors routinely fly to nearby Utah and back.
Moreover, both California and Arizona condors are finding and eating food on their own. Dead deer, elk, coyotes, beaver, and livestock make up most of their diet. The older condors in Arizona now find 1520 percent of their food on their own, says William Heinrich, the Peregrine Fund's species restoration manager, although biologists still place carcasses at feeding sites to try to ensure the birds gel, at least, some Lead-free food.
Even more important the released condors may be on the verge of becoming a self-sustaining population in the wild. One chick successfully fledged in Arizona in 2003, the first in the wild in two decades. Five more chicks hatched in the wild in 2004, three in California and two in Arizona. One came from an egg laid by AC-9, one of the last condors captured front the wild in the 1980s and since released to her old haunts in California. Additional releases this fall will bring the wild populations to more than one hundred, another milestone. Most significant, few wild condors have bad to be recaptured since 2001, and none has died since last October.
Finally, the U.S. Fish and Wildlife Service is working with hunting and shooting groups to educate hunters on how to keep condors and other wildlife free from lead poisoning The multi-year effort, scheduled to begin with this fall's hunting season, will use magazine, newspaper, and newsletter articles; educational brochures; and package inserts that accompany hunting permits to encourage hunters to use nonlead bullets and shot.
For hunters who still use lead, the campaign will encourage them to find and clean any deer or other animals they shoot, including hiding gut piles so condors do not see them. "We need to make hunters part of the solution rather than having them feel they are being imposed upon," says Robert Byrne, wildlife program coordinator for the Wildlife Management Institute in Washington, D.C.
For Mike Wallace, such efforts signal hope that the California condor might soon reach the recovery, program's goals of 150 birds in each of the two release areas (California/Baja and Arizona) and another 150 in captivity. "We've brought the condor front the brink of extinction and are gradually approaching a self-sustaining population in the wild," he says. "If we can continue to reduce annual mortality to a reasonable rate and improve condor behavior in our released birds, we will have something we all can be proud of ... a fully recovered species. I believe we're on the right track."
Jeffrey R Cohn is a frequent contributor" to Americas on science and conservation
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|Author:||Cohn, Jeffrey P.|
|Publication:||Americas (English Edition)|
|Article Type:||Cover Story|
|Date:||Sep 1, 2004|
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