- Home
- Jane Goodall; Thane Maynard; Gail Hudson
Hope for Animals and Their World Page 5
Hope for Animals and Their World Read online
Page 5
Some time passed during which Gary heard nothing. And then, finally, Jim called: “We had some difficulty mapping the area,” he said, “because we had to miss some sand dunes, and some stands of desert oaks … How does 170 hectares [approximately 420 acres] sound?”
It sounded great! An enclosure of this size was just the “fillip” (an Australian/British phrase for “boost”) that was needed for the program, Gary told me. He felt very strongly about the outcome of the reintroduction not only for conservation of the species, but also for the conservation of the culture of the Anangu.
Six years later to the month, at 7 AM on September 29, 2005, twenty-four mala were released into the newly constructed, predator-free paddock in the Uluru- Kata Tjuta National Park. Many Ananga were present, and the press was well represented. It was a fantastic occasion, the culmination of years of planning and hard work.
Just as I was completing the manuscript for this book, I received an e-mail from Peter Nunn, a staff member at Alice Springs Desert Park. “I thought you would love to know that the Mala you released into our Free Range area at the Alice Springs Desert Park is doing really well,” he wrote. “So well in fact that she has a young joey growing in her pouch! I was lucky enough to have her wander straight past me when I was spotlighting up there the other night, and she is looking wonderful. I hope that great news puts a big smile on your face!”
And, indeed, it did.
SURROGATE MOTHERING OF JOEYS
The Story of the Black-Flanked Rock-Wallaby
(Petrogale lateralis)
Just after I met my first mala, I also met my first black-flanked rock-wallaby at the captive breeding programs of Monarto Zoo, near Adelaide. Peter Clark, the senior curator, told me that as a result of environmental degradation and predation by and competition with introduced species, numbers of “warru” (to give the species its Anangu name) had plummeted to a low of only fifty to seventy individuals.
Then in 2007, a clever plan was implemented to try to save it—one that has been used very successfully to boost numbers of other endangered wallaby species. It is based on an unusual reproductive strategy: If a female wallaby loses a joey, she is able to replace it by activating a fertilized egg that she has stored internally. And so a team of biologists working in the field capture female warru, check their pouches, and if they find tiny, partially developed joeys, they “steal” them and take them by plane to Monarto Zoo, where they are implanted into the pouches of non-endangered yellow-footed rock-wallabies (Petrogale xanthopus). Because the stored “contingency” embryos soon start to develop in the wild mothers, there is no loss to the wild population.
Members of the local Anangu community accompanied the first twenty stolen joeys (each of which they had named) on the flight to Monarto. All survived the capture and journey and thrived in the pouches of their new mothers, Peter told me. But then, before they became too independent, they were taken away so that their rearing could be taken over by zoo staff. This was important, Peter said, since they will be used for captive breeding during which it will be necessary to check their pouches frequently, and this will be much less stressful if they are familiar with their human handlers.
Currently both the government and the local Anangu people are carrying out continuous monitoring of the warru population in three remnant rock-wallaby sites, using tracks, scats, and radio tracking of previously trapped individuals. While numbers are still low, it is encouraging that several new individuals have been found. These are the areas where the captive-bred warru from Monato will eventually be reintroduced once there are enough of them, and once predator control programs are working satisfactorily.
Before I left, one of the keepers, Mick Post, took me to meet a breeding female. She had arrived with the second group of joeys who had been named by zoo staff, and instead of having an Aboriginal name she was called Maureen! She was enchanting—an elegant-looking animal, about one and a half feet tall when she sat upright. Her fur was dark gray with blackish stripes on her face and flanks. She was completely at ease with us—and when I sat on the floor of her enclosure she climbed onto my knee and just sat there, looking around with interest at the cameras pointed at us. Mick said that she sometimes sits on his head as he is cleaning her enclosure, watching all that is going on. It was a real privilege to meet the dedicated team working to ensure the survival of Maureen and her relatives and descendants.
Captive-bred California condors released into the wilds of Baja California, Mexico.(Mike Wallace)
California Condor
(Gymnogyps californianus)
The California condor is one of the biggest birds in North America, weighing up to twenty-six pounds and standing nearly a yard tall, with a wingspan of nine and a half feet. As a child, I knew only about the vultures of Africa and Asia, for they frequently figured in my storybooks—usually in a somewhat sinister role as they patiently watched the hero, close to giving up as he struggled across the desert, thirsty and wounded. But one look at their hooked beaks, sharp talons, and cold greedy eyes, and he would summon the strength to reach safety. During my years in Africa, I have spent many hours watching the fascinating behavior of those vultures in the wild, but the California condor, which I learned about much later, I have seen only in captivity.
Initially, I was not attracted by its appearance. The bare skin of the head is so—well—bare! And its redness is the color of a boiled lobster. Truly, the condor is one of nature’s odd experiments, where so much of the poetry, so much of the magic, went into the fashioning of those glorious wings and stunning power of flight. Yet not quite all—for in photos of condors in the wild I’ve come to appreciate their splendid red skin standing out against jet-black feathers, glowing in the sunlight. And gradually, their faces have grown on me, slightly comical, endearing.
At one time, California condors ranged widely—from Baja California in Mexico all the way up the West Coast to British Columbia in Canada—but by the 1940s, they had disappeared almost everywhere, except for an estimated 150 in the arid canyons of Southern California. In 1974, there were reports of two condors in Baja California, and my late husband, Hugo van Lawick, was asked to fly down to try to film them. But the expedition never materialized, and the birds disappeared.
The decline in condor numbers was due to many factors, such as the number of people moving into the western United States, shooting by poachers and collectors, feeding on poisoned baits set out for bears, wolves, and coyotes by ranchers, and, perhaps most importantly, the unintentional poisoning from lead ammunition fragments in the carcasses and gut piles of animals shot by hunters.
A group of biologists decided that something must be done. True, an area of wilderness had been set aside for the condors, but it was not enough. It served to protect them when they were nesting—and it was a preferred place for that—but when they foraged, they would fly a hundred miles or so into the ranchlands, where there was no protection at all. Noel Snyder, a biologist and passionate advocate for the birds, helped to establish the Condor Recovery Program and subsequently led the condor research effort. Biologists sought to discover all they could about condor behavior and the causes for the decline in numbers, while at the same time planning a captive breeding facility so that additional birds would become available to boost the wild population.
But there were many people vehemently opposed to any kind of intervention, and a controversy began that continued for years. The “protectionists” wanted to give the birds better protection in the wild, and if this did not work, to let them gradually disappear, to die with dignity in their natural habitat. They maintained that some condors were sure to be accidentally killed during capture; that they were unlikely to breed in captivity; and that, even if they did, it would be impossible to reintroduce them to the wild.
I remember visiting the San Diego Zoo during that period and discussing the issue with some of the scientists, including my longtime friend Dr. Donald Lindburg. Part of me shrank from the idea of depriving the wil
d birds of their freedom, imprisoning those wondrous winged beings in enclosures, perhaps for the rest of their lives. But another part felt—along with Don and Noel Snyder—that it would be worth it to save such a magnificent species, so long as they could be released back into the wild. In the end, Noel and Don and the other interventionists prevailed.
The Condor Becomes Extinct in the Wild
In June 1980, five scientists, led by Noel, set out to monitor the progress of the single chicks in each of the only two known “nests” in the wild. (For condors, nests are simply ledges of rock, usually in caves.) Imagine the team’s dismay when, after they had checked on the first chick without problems, the second died of stress and heart failure during the process. This, naturally, led to a storm of protest from the protectionists—which Noel somehow weathered.
In 1982, a hide was built near a wild condor nest so that the behavior of the birds could be studied. The observers could hardly believe the extraordinarily dysfunctional behavior they witnessed. Every time the female returned to take her turn at incubating her egg, she was subject to violent aggression from her mate, who apparently did not want to relinquish care of the egg. The male repeatedly chased her from the nest cave, sometimes continuing to do so for days, while the egg meanwhile suffered unnaturally frequent and long periods of cooling. Finally, during one such squabble, the egg rolled out of the nest cave and smashed on the rocks below.
The observers thought that this meant a sad end to the pair’s reproductive activities for the year. But a month and a half later, they produced another egg, which was laid in a different cave. Although this egg was also lost when the pair resumed squabbling—this time to a raven—the study was important because it established that condors, like many other birds, will be stimulated to breed again and lay replacement eggs if they lose one to predation or some kind of accident. Noel and his team then began a major effort to establish a captive breeding population by taking first-laid eggs from all wild pairs for artificial incubation.
How fortunate that they did, for over the winter of 1984–1985, tragedy struck the wild population. Four of the five known breeding pairs were lost. Reasons for the birds’ disappearance were unclear, but there was mounting evidence that they were dying from lead poisoning. At this point, Noel and his team felt it imperative to capture the remaining wild birds. There were so few condors in the breeding program and they lacked the genetic variability to be self-sustaining—and there were but nine wild birds left. Only by establishing a viable captive population, Noel maintained, could the California condor be saved.
The National Audubon Society, however, strenuously opposed this plan, arguing that habitat could not be protected for the species unless some birds were left in the wild. In an attempt to prevent taking the last wild condors captive, the group sued the US Fish and Wildlife Service (USFWS). But after the female of the last breeding pair became a victim of lead poisoning and died, despite attempts by veterinarians to revive her, a federal court ruled that the USFWS did indeed have the right to capture the remaining wild birds. And so, between 1985 and 1987, the last wild California condors were taken into captivity, and the species became officially extinct in the wild.
Visiting the Breeding Center
By this time, two state-of-the-art breeding facilities had been established, one in the San Diego Wild Animal Park and the second in the Los Angeles Zoo, each with six enclosures. During five years, starting in 1982, sixteen eggs (of which fourteen hatched and survived) and four chicks were taken from the wild and shared between the two facilities. And there was one male, Topa-topa, who had been living in the Los Angeles Zoo since 1967. These captives were then joined by the last seven adults from the wild. Bill Toone was in charge of incubating the eggs, and thanks to the techniques he and his team developed, 80 percent of the eggs resulted in healthy young birds—compared with a 40 percent to 50 percent success rate in the wild.
In the early 1990s, Don invited me to visit the condor breeding center and flight cage at the San Diego facility. As with most such programs when reintroduction into the wild is an end goal, great care was taken to ensure that the captive-bred condors did not imprint upon their human keepers. Those caring for the chicks were equipped with glove puppets mimicking the head and neck of an adult condor, and no talking was allowed near the birds. In silence I peered through one-way glass and saw one of the original wild hatched females sitting, unaware of my presence, on a ledge of man-made rock. As I watched her suddenly take off and, with only a couple of flapping movements, glide on those majestic wings across her very large flight cage, I felt tears sting my eyes. Partly because of her lost freedom; partly because I knew that but for a handful of passionate, courageous, and determined people, this glorious winged being would almost certainly have died—shot or poisoned—like so many others before her.
More than two decades later, in April 2007 (on my birthday!), I visited the Los Angeles breeding program and met team members Mike Clark, Jennifer Fuller, Chandra David, Debbie Ciani, and Susie Kasielke. We gathered in a small room where video screens showed the twenty-four-hour recordings of behavior in the breeding enclosures. As we talked about the successes and problems of the program, we watched on a monitor (from a remote camera set up in a breeding pen) a wonderful courtship display by a young male. And there was a female there that was getting ready to lay her first egg. It was not due for several days, but already she was looking most uncomfortable, her tail raised and her head low. She pecked up and swallowed a few small fragments of bone, a behavior thought to provide extra calcium for building the egg’s shell.
Preparing Young Condors for a Life in the Wild
An urgent problem facing the pioneers who embarked on captive rearing was to find the correct method of raising the young birds for ultimate release. Because the California condors were so perilously close to extinction, they could not afford to make many mistakes. So the team decided to carry out a trial release with Andean condors, since this species, with its fabulous eleven-foot wingspan, is not nearly so endangered. Thirteen youngsters would be raised and released temporarily in Southern California, allowing the team to test their methodology before any of the precious Californians were freed. The Andeans, all females, were raised as a peer group and all released at the same time. It was thought that they would provide one another with companionship and support one another. And indeed, it worked well. (The Andean condors were later recaptured and ultimately re-released in Colombia, where many are now breeding and rearing chicks of their own.)
Flushed with the success of the Andean program, the biologists confidently raised their young California condors in the same way. Alas, Mike told me, group rearing simply did not work for them and led to all manner of behavioral problems. It seems that California condors need discipline from an adult bird. And so a new method was devised. Each chick remains for the first six months in a solitary nest box, in view of an adult male condor, cared for and fed by a disguised human using a condor head puppet. Then, at the time when a wild fledgling would leave the nest, the youngster joins an adult mentor—a male of ten years or older. This mentor competes for food with the young bird but without being aggressive and is, said Mike, “good for its mental development.”
However, as the condors matured, additional behavioral problems arose. For one thing, proper male–female bonding was not happening until, through trial and error, scientists learned that putting a mature male and female, genetically suitable for each other, in an enclosure with young birds worked best. “Each adult bird then prefers the other’s company over that of any of the youngsters,” said Mike.
Once bonding is achieved, mating is no problem, and such pairs regularly produce eggs. And the raising of chicks by parents in captivity was also relatively trouble-free. “The sight of an egg,” said Mike, “seems to trigger an instant paternal response in the male, who becomes very protective of it.” The pair take turns incubating the egg for the fifty-seven days before it hatches. After this the male continu
es to be very protective, though the mother tends to compete with her chick for its father’s attention.
Odd Parenting Back in the Wild
By 1991, eleven of twelve captive pairs had produced twenty-two eggs. Seventeen of these were fertile, and thirteen had hatched and matured. Things were going well. By 1992—less than ten years after the program began—the first two captive-bred condors, each with a radio tag, were released into 398,000 acres of protected wilderness, including thirty miles of protected streams, in Los Padres National Forest. In an attempt to protect these birds as much as possible from the risk of lead poisoning, food was (and still is) set out near the release site. Even though they can fly more than a hundred miles in a single flight, it was hoped that these California condors would, as had the test group of Andean condors, return to easily available food when hungry—which they mostly did.
In 2000, the first captive-bred birds nested in the wild—an event that is always awaited eagerly by the people who have worked so hard to return animals to a life of freedom. But it was at this time that some of the behavioral problems affecting the captive-raised birds became apparent. When biologists found the nest, they were amazed to see not one but two eggs! And they discovered that there were three birds to this one nest, one male and two females. They had, however, chosen a very appropriate cave, where the females had laid eggs several feet apart. The three took turns sitting at the nest site—but one bird could not sit on both at once, and so the biologists decided to intervene.