Getting the lead out: lead bullets still threaten the California condor, an icon at Pinnacles and Grand Canyon.
More people are getting the chance to witness these endangered birds firsthand, thanks to reintroduction programs in California and Arizona that have expanded condor populations from an all-time low of 22 individuals in 1982 to more than 400 birds today. "They're breeding in the wild and fledging their own young, which paints a hopeful picture," explains Scherbinski. But as condors venture farther from release sites, these scavengers encounter a lethal menace: Lead ammunition embedded in the carcasses they eat is poisoning the birds and threatening the species' recovery.
Lead weakens condors' immune systems, interferes with reproduction, and remains the species' leading cause of death. (Arizona confirmed 23 losses since 2000.) Consequently, monitoring birds' lead levels--and providing emergency treatment when they're dangerously high--is biologists' top priority, which draws attention away from other priorities.
At Pinnacles, crews use GPS transceivers to monitor 32 birds year-round, and trapping sessions in spring and fall allow technicians to replace GPS batteries and check birds' lead levels. If blood levels measure less than 35 micrograms of lead per deciliter of blood, the condor is released. But 35-65 micrograms necessitates hustling the bird to Pinnacles' new Condor Care Unit, where it's given an injection of ethylenediaminetetraacetic acid (EDTA), which allows the bird to excrete the lead. More than 65 micrograms, and the condor is rushed 300 miles to the Los Angeles Zoo for intensive care; this summer saw six such emergency missions. "Without these efforts, condors would fall back to the days of 22-member populations," says Scherbinski.
Although lead exposure comes from a variety of sources--last year Pinnacles removed lead paint from a fire tower after workers discovered that birds were eating the flaking paint--overwhelmingly, the culprit is lead ammunition. A California law enacted in 2008 requires hunters to use bullets made from copper or steel within the state's condor range. Still, birds continue to get sick: Up to 88 percent of wild condors monitored in California show signs of lead exposure every year, and 20 percent end up undergoing treatment.
The ban on lead bullets applies only to locations known to support condor populations. But as condors expand their range beyond unleaded zones, they ingest lead fragments in gutpiles (innards left behind when hunters dress their kill), in wounded prey that escaped the hunter, and in the carcasses of squirrels and pigs that are killed by property owners.
What makes the problem so pervasive is lead's tendency to fragment into hundreds of tiny pieces throughout the animal carcass. That fragmentation dissipates the bullet's energy and provides a clean kill. "But the fragments go everywhere," says John Schulz, a hunter and non-lead campaign manager for the American Bird Conservancy. "You can't remove them just by cutting around the wound channel," he explains.
Those fragments poison more than just condors. Some 500 peer-reviewed studies have detailed the negative impacts of lead ammunition on 130 wildlife species worldwide, including bald eagles, golden eagles, and turkey vultures. And disease centers across the globe have found that people who eat wild game harvested with lead bullets develop elevated lead levels themselves. Says Schulz, "People don't realize the extent of the bullet fragmentation with traditional ammunition, and until they do, condors and other birds will remain at risk."
Anthony Prieto is one of the enlightened. An avid hunter of pig and black-tailed deer, Prieto started volunteering with California's condor recovery program in 1998 when he helped to trap and tag birds and test their blood levels. "I saw lead's detrimental effects firsthand, and I thought, 'Wow! If it affects condors like this, it must also affect my kids,'" he recalls. The realization prompted him to stop feeding his family with the meat he hunted--and to seek alternatives to lead ammunition. "The copper bullets I use now are even more accurate, don't fragment, and result in a cleaner, quicker kill, when the shot hits a vital area," he says. To encourage his fellow hunters to adopt the same approach, Prieto is a co-founder of Project Gutpile, which promotes lead-free options.
Hunting is a culture of tradition, and as Prieto points out, people are slow to change. The cheapest lead bullets are generally cheaper than low-end copper and alloy alternatives (but among premium ammunition, lead is actually more expensive than the alternatives). Lead is denser than copper and alloys, so hunters adapting to new ammo need to spend time at the shooting range re-adjusting their scopes, to ensure they hit their targets with the lighter bullets.
But conservation is another tradition among hunters, and educational outreach can appeal to those values, says Chris Parish, a former biologist for the Arizona Game and Fish Department, who oversees the condor reintroduction program for the Peregrine Fund. A hunter himself, Parish hosts shooting demonstrations for hunting groups comparing the fragmentation and accuracy of lead and non-lead ammunition--and manages to convert most hunters to lead alternatives as a result.
A voluntary program initiated in 2002 by the Arizona Game and Fish Department distributes free boxes of non-lead ammunition for hunters to try, and asks hunters on the Kaibab Plateau (north of Grand Canyon National Park) to use non-lead ammunition or to pack out their gutpiles when using lead. In each of the last five years, 80 percent of the hunters got with the program, and the number topped 90 percent this year. Utah, which is starting to see condor traffic, is launching a similar program, and Canadian organizations may follow suit. In fact, Schulz sees such partnerships as the only way out of the lead problem. "We've made phenomenal progress by using a positive, respectful approach," he says. "The best way to help these birds is to get folks engaged in meaningful dialog and to keep that conversation going."
Scherbinski believes the best agent for positive change is getting people to visit Pinnacles or Grand Canyon, where they can feel the power of glimpsing North America's largest flying land bird. "Condors aren't extinct. You don't have to go to a museum to see a stuffed specimen. You can see them live, right here," Scherbinski says. "That's more powerful than any talk about conservation."
No condors have been released in any of the Southwest's national parks. But as visual scavengers, condors are attracted to any kind of human or animal excitement or "buzz" on the landscape and thus have gravitated to visitor hubs at Bryce Canyon, Glen Canyon, Zion, and the Grand Canyon, where spotting scopes on both rims afford an up- close view of these endangered birds.
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|Date:||Mar 22, 2013|
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