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Devices that helped save condors now used for other
endangered animalsIn this story:
April 24, 1997
Web posted at: 3:57 p.m. EDT (1957 GMT)By Gali Kronenberg
For more than 40,000 years, California condors soared over North America. Air currents lifted them more than two miles high. Winds, harnessed by their 10-foot wingspan, propelled them as fast as 60 mph.
But when settlers came West, the California condor started to disappear. Farmers shot them. Hunters stole their eggs. And, more recently, power lines have killed them.
By the mid-1980s, this majestic bird with a beak sharp enough to tear meat from bone faced extinction.
Today, as a result of breeding programs at zoos and wildlife parks in Los Angeles and San Diego, 125 California condors live in captivity. Twenty-five have been released in protected areas such as Big Sur, New Cuyama, the Sespe Condor Sanctuary in Los Padres National Forest and the Vermilion Cliffs, a refuge near the Grand Canyon. And some of the techniques used to help save the condor are now being applied to help save other species.
The California condor's comeback is in part because of technology and the efforts of a wildlife biologist who used telemetry to track the ancient bird.
"In order to release birds back into the wild, we needed to know where they were going, what they were doing and what was killing them," said Michael Wallace, the curator of conservation and director of the condor program at the Los Angeles Zoo.
"You would think that given the bird's size they would be easy to track," Wallace said. "They're not."
Tracking the condors
A California condor can range 100 miles per day. That may sound like a short enough distance for a biologist in a Jeep to traverse, but not when it's over roadless mountains. For years, volunteers climbed peaks in the Los Padres National Forest to gauge the condor's population and behavior.
"The problem," Wallace said, "was you never knew if the group (of) five condors flying east from Mt. Able were the same condors spotted at Mt. Frazier flying west."
But by adapting transmitters similar to those used to track bald eagles, Wallace was able to develop a lightweight, aerodynamic transmitter that -- unlike the backpacks used on other species -- could be clipped to a condor's wing.
This transmitter is powered by a lithium battery and emits a signal that in ideal conditions can be heard for more than 100 miles. The problem, Wallace said, is that condors tend to spend a lot of time catching rising air currents off cliff faces, where the signal is blocked or bounced.
"There is definitely an art to interpreting the signal," Wallace said. "When it varies, you can't be sure if its because a condor has flown behind a mountain or if it's scratching itself."
But keeping tabs on the condors' whereabouts is crucial to survival. With no adults left in the wild to teach the zoo-bred vultures survival skills, field biologists act as surrogate parents.
Many of the condors closely related
At night, the biologists leave out a diet of deer and cattle carcasses. This is to encourage the condors to stay within their sanctuary and to discourage them from feeding on the poisoned flesh of animals killed by hunters using lead shot.
Another threat to the California condor is that with so few birds left, many of them are closely related. Genetic testing helped biologists determine that all of the California condors alive today stem from 14 genetic lines.
"So it is crucial that we don't ever mix these birds up," Wallace said. "To ensure the condors' survival, we need to make certain not to pair up a mother and a son or a brother and a sister."
Of course, one red-eyed vulture tends to look like another. To keep their identity straight, biologists clip a vinyl tag to their wings and insert a microchip in each bird's back. The chips can be read with a hand-held scanner similar to those used to tally the price of a dozen eggs.
Such techniques are being used to help save other species too.
The story of Brutus and Tara
A pair of golden lion tamarins at the Los Angeles Zoo, Brutus and Tara, wear transmitter collars that resemble pendants. Normally, the monkeys stay close to home, in a small hutch next to a pepper tree, but the collars allow their keepers to follow them when they forage outside their cage for lizards and beetles.
Like the condor, Brutus and Tara, whose species is also threatened, were raised in a zoo and will also one day be returned to the wild. Letting them forage is one way to prepare them for life outside.
"My approach is to use whatever technologies are available, whether modern or ancient, to achieve the goals of wildlife conservation," Wallace said.
While studying the Andean condor in Peru, he adopted a traditional Inca technique to trap the birds. Hiding in a pit, he covered himself with branches, a woven basket as a trap and a sheep carcass as bait. Within a day or two, a hungry condor was sure to appear.
On one occasion, Wallace learned firsthand how condors feed in the wild. When his back was turned, an Andean condor sampled a chunk of his buttocks.
Despite the incident, Wallace remains committed to his work. If anything, his plans have grown more ambitious. He hopes to place transmitters on condors in Argentina so he can monitor their movements via satellite from Los Angeles.
Sounds like a healthy strategy for the condor -- and Wallace.
(c) 1997, Los Angeles Times Syndicate
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