The dreaded signal sounded just after Christmas — the sustained tone that indicated Condor 127 had stopped moving. Word passed quickly through the tight ranks of the small team of biologists that have labored for the past decade to re-establish condors in the wilds of the Grand Canyon, from a release site atop the Vermillion Cliffs.
The death signal set off an arduous search for the body of one of about 74 California Condors in Arizona.
Biologist Eddie Feltes feared the worst — another victim of lead poisoning as a result of eating the carcass of a deer killed by a hunter who hadn’t yet switched to lead-free bullets.
More than a decade of effort has brought the California Condor back from the brink of extinction. The largest flying birds on the planet, condors grow to 26 pounds with 9.5-foot wingspans. Biologists captured the last wild condors in California in 1987 and started a captive breeding program. They began releasing condors back into the wild in Arizona in 1996 after a 72-year absence from our skies. The population has since grown to 350 birds, including 161 birds in captive breeding programs in San Diego, Idaho, Oregon, Mexico City and Santa Barbara. Another 95 live in the wild in California and 18 in Baja, Mexico.
Once biologists had triangulated the signal, they took a National Park Service helicopter ride into the inner gorge of the Grand Canyon, then climbed down to the carcass of Condor 127, a 15-year-old female who had produced at least three with her mate, Condor 123. Notoriously slow breeders, condors usually produce a single chick every two years.
The results from the medical lab set up as part of the reintroduction effort confirmed that the first female to successfully rear a chick in the wild had succumbed to lead poisoning.
Tragically, the death signal sounded again a few weeks later. Once again, the signal led biologists deep into the Grand Canyon where researchers rappelled down a cliff face to find the body of Condor 472 — the child of that pioneering pair. Tests showed he too had died from lead poisoning.
Worried biologists then set out to trap the now widowed Condor 127, who remained forlornly in the canyon where his longtime mate and son had both died — perhaps from feeding on the same carcass.
Studies by the condor biologists have revealed that lead bullets fragment when they strike a deer, spreading tiny particles of lead throughout a large area of the carcass.
Then on Dec. 29, the battered biologists received a third signal. This time, they had to wait out a winter storm before hiking to the signal and discovering the body of a 6-year-old male — who also died from the effects of lead poisoning.
The three deaths within a matter of weeks represented about 4 percent of the entire Arizona population — and underscored the sometimes controversial findings about the possible impact of lead on scavengers — and perhaps even on hunter’s families.
The research has demonstrated lead contaminates a large area around the bullet wound. These fragments interfere with the digestive system of condors, prompting them to weaken and starve if not treated. Biologists attempt to trap each condor twice a year so they can test them for lead levels and treat them if necessary.
The lead fragments may well affect other birds that feed on carcasses, like bald eagles and golden eagles. Moreover, some experts worry about the impact on humans of eating meat contaminated with lead, since even very low levels of lead can have developmental effects, especially on children.
The research prompted the Arizona Department of Game and Fish to offer lead-free ammunition to any hunter with a tag in the areas where the condors now range — generally from the South Rim of the Grand Canyon all the way up into Utah. That move resulted in a sharp drop in condor deaths for three years, until this winter’s relapse.
The push by the Peregrine Fund, which runs the condor recovery program for the federal government, spurred conflict with some hunting groups, afraid it would lead to a wider ban on lead-based ammunition. Bullets made from metals like copper do not fragment or have the same toxicity as lead.
Lead contamination has proved the single biggest threat to the expensive, but heartening attempt to prevent the extinction of the planet’s largest bird of flight.
Just last weekend, biologists released several more captive-reared condors from an enclosure atop the Vermillion Cliffs, not far from Marble Canyon Lodge. Those birds will help replace the winter’s losses among the wide-ranging flock of Arizona Condors.
Condors soared across much of North America 10,000 years ago, feeding on the Ice Age carcasses of Ice Age monsters like mammoths and giant ground sloths. But the last condor was sighted in Arizona in 1924 and the total population had dwindled to 22 birds in California by 1983. The 1987 release here of the first of the gigantic, long-lived birds proved the start of a long, slow process.
None of the young, captive-reared Arizona condors had shown any sign of actually raising chicks until the spring of 2003, when one of the life-mated pairs started working shifts on their presumed nest inside a cave in the Grand Canyon. When they seemingly abandoned the nest just when they should have laid eggs, biologists used a helicopter to land on the cliff top above the nest, so they could rappel down and discover what had happened.
Inside, they were disheartened — but not surprised — to find shards of condor eggshells among the regurgitated hairballs and pellets of the nesting adults. Condors don’t start rearing young until they’re 6 or 7 years old and usually don’t succeed in their first two or three attempts.
But in the back of the cave, the biologists made a much more inspiring discovery: Condor bones dating back to the Ice Age.
Clearly, the condors had come home.
Triumphantly, later that summer Condors 123 and 127 produced the first chicks to survive.
Since then, the Arizona flock has produced nine young that have survived. However, the population has lost a total of 45 birds — a third of those to lead poisoning. Clearly, the population remains a long flight from self-sufficiency, without the help of the captive breeding program.
Giant vultures that live entirely on carrion, condors once seemed doomed to extinction by the destruction of the great herds of North America and the spread of human settlements. Their range had already shrunk to a strip of coastal California by the mid 1950s, when they were hit by the same eggshell-thinning effects of DDT that nearly exterminated bald eagles. They also frequently died as a result of landing on power lines and eating the hunters’ bullets in carcasses.
Fortunately, the condors proved amenable to captive breeding programs. Biologists discovered that if they removed the egg from a breeding pair, the baffled couple would lay up to three eggs per year.
But figuring out how to return the curious, social, intelligent birds to the wild proved much more difficult.
The first flock released in California behaved like a youth gang. They flocked to a country club golf course, where they sat around watching people around the barbecue pits — making buzzard comments among themselves. Some took to attacking cars in the parking lot and ripping off the windshield wipers.
“It was like Lord of the Flies,” observed one biologist. More to the point, in the first year about 20 percent of the released birds died — mostly as a result of encounters with power poles and human beings, plus one bird that drank from a roadside pool of antifreeze.
Biologists recaptured that first flock and redesigned the captive rearing methods. This time, biologists kept the birds away from any human contact.
They fed the chicks with condor hand puppets. If possible, they placed chicks with adoptive condor parents, since painful trial and error demonstrated that chicks raised by real birds fit much more easily into the dynamics of a flock, where shared vigilance, social learning and the social organization of a pecking order dramatically increased survival.
Biologists also concentrated on teaching the birds to avoid their two greatest dangers — power lines and human beings. Keepers built fake power lines in the bird’s enclosures, which delivered a mild electric shock if they landed on the poles.
They would also occasionally have a human being stand at a distance from the enclosure. Once the birds were all focused on the distant human figure, keepers would rush suddenly out of hiding — shouting and stamping — hoping to instill fear of human beings.
The new conditioning paid off when biologists again released condors into the wild.
The condors have made a sometimes halting, mostly heartening adjustment to their ancient surroundings, riding the thermals over a mostly empty landscape. Biologists continue to put out calf carcasses near the release site, but the condors now get most of their food from the bodies of deer, cattle, mules and other animals.
Lead poisoning remains the biggest killer, but three condors have been shot, apparently by random hunters.
One condor was apparently killed by a golden eagle — several pairs of which nest near the release site. Coyotes have claimed several others, mostly young condors who couldn’t quite manage a tricky landing on a ledge and foolishly elected to spend the night on the ground.
Gradually, the condors have acquired the survival skills that they would have learned from their wild parents.
Ambitious individuals have ventured north 200 miles or more, looking for dead things on up into Utah. They regularly patrol the shores of Lake Powell, venturing up to the natural stone arch of Rainbow Bridge on the shores of Lake Powell. Many patrol the Grand Canyon and frequently delight river runners by putting in an appearance near Navajo Bridge around Lee’s Ferry.
But it’s the flock’s affection for the heavily populated South Rim of the Grand Canyon that most boggles biologists and delight tourists. Condors can’t smell at all, unlike turkey vultures who can sniff out the delicious aroma of rotting flesh from miles away. However, the inquisitive condors are drawn to any activity by their binocular vision. They often spot gatherings of vultures or ravens from vast distances and drift over to investigate. The condors are irresistibly drawn to the South Rim by a colony of turkey vultures, mobs of ravens, long trains of mules, and scurries of frail, two-legged mammals that look like they might topple over and die at any moment.
The appearance of condors inevitably draws neck-craning exclamations from those delighted potential menu entries. But the lurking condor watchers know that losing their carefully instilled fear of humans could doom the flock and a reintroduction effort that costs more than $1 million per year.
Most of the money is privately raised by the Peregrine Fund, which manages the reintroduction along with a heartening array of state, federal and private organizations. The condor watchers track every bird with radio transmitters and binoculars and so rush up to frighten them off every time a condor lands near a gaggle of tourists. The biologists urge the camera-clicking, condor-coddling tourists to stay well away from the birds — or yell, flap and generally scare them off to reinforce the conditioning.
If a condor proves too fearless for his own good, biologists will sneak up, grab him by the legs and take him back to the captive rearing pens for a good talking to concerning the inherent untrustworthiness of human beings. One condor developed the disconcerting habit of visiting the camps of river rafters and going through their things.
On another occasion, the body of a pack-train mule that tumbled off the trail drew a flock of condors, which perched on the Bright Angel Trail above the body. Another condor enjoyed strolling about on the trails along the South Rim until biologists grabbed him and shipped him off for reconditioning.
The three deaths this winter have renewed fears about the long-term effect of lead poisoning, even though the biologists now have a complete lab to do X-rays and chelation therapy close to their headquarters at Marble Canyon.
On the other hand, biologists are hoping for a happy postscript to the sad tale of Condor 123, who was successfully treated for lead poisoning after the death of his little feathered family.
He’s started flirting, in the goofy, fluffed up condor way, with the much younger Condor 316 F. She seems interested in the poor old geezer.
And it’s true enough — condors mate for life and Condor 123 had 15 good years with his first love.
But, well: A condor does have his needs, after all.