Arizona's program to reduce the exposure of endangered California condors to lead from spent ammunition is so successful that a similar education and outreach effort now under way in Utah.
This will greatly enhance the survival of the species in this region, says The Peregrine Fund, an Idaho-based conservation group for birds of prey.
The growing condor population spends part of the year searching for food in southern Utah as well as northern Arizona. A peer-reviewed study published in the December issue of the international science journal, PLoS ONE, shows that a self-sustaining condor flock that can survive free of constant human intervention will require substantially reduced exposure to lead-based ammunition during the hunting season near Cedar City, Utah.
Authors of the study are Rhys E. Green of the University of Cambridge, Chris Parish and W. Grainger Hunt of The Peregrine Fund, and Ian Newton of the Centre for Ecology and Hydrology and former chairman of The Peregrine Fund's board of directors.
"Thankfully, there are excellent alternatives to lead ammunition, such as copper bullets, and several major manufacturers are now producing premium non-lead rifle ammunition," said Parish, condor release biologist for The Peregrine Fund and an avid hunter. "We are grateful to all the hunters in Arizona who have voluntarily joined us in this unprecedented effort to conserve the California condor and we are confident that Utah hunters will do the same."
The newly published study shows that carcasses and gut piles of game animals killed with lead ammunition on the Kaibab Plateau of Arizona and the Zion region of southern Utah are the largest sources of lead for condors in the Grand Canyon population. Those zones are attractive to condors during the hunting season because of the large quantity of remains of hunted deer and elk available as food there.
Researchers used data collected over three years, including satellite tracking of condors to determine where they forage and blood lead levels of condors captured and tested several times each year. The complex analysis showed:
The existing program of hunters using non-lead ammunition in the Kaibab area is having a large beneficial effect on condor survival. Without the program, the birds would experience a much higher death rate.
Extending the program to the Zion region of Utah would further reduce lead poisoning in condors.
The joint effect of reducing exposure to spent lead ammunition in Arizona and Utah would greatly increase the species' chance of surviving without the intensive and costly management now required to sustain the population.
"Our research shows that including the Utah region in our lead-reduction effort is essential if we are ever to have a self-sustaining population of free-flying condors that do not require frequent capture and other human intervention," Parish said.
For five years, The Peregrine Fund has participated in an awareness program for Arizona hunters to voluntarily switch to non-lead ammunition or retrieve the remains of game animals shot in condor country. Each year, hunter participation has increased and, as a result, fewer condors have died of lead poisoning, the leading cause of mortality. In 2008, 90 percent of hunters participated, up from 80 percent the year before, reflecting the conservation ethic of the hunting community, Parish said.
"We are very encouraged by the high participation rate in 2008 and the year-over-year increases since the program began," says Kathy Sullivan, the condor program biologist for the Arizona Game and Fish Department. "It clearly indicates that hunters are aware of the conservation challenges condors face, and they are willing to voluntarily take action to reduce the available lead."
Of the 90 percent of successful big game hunters who took lead reduction efforts, 654 used non-lead ammunition during the fall hunts in the condor's core range. Another 160 hunters removed gut piles from the field or took other action to reduce the condor's access to lead.
The department started offering free non-lead ammunition in 2005 to hunters drawn for hunts in the condor's core range. The free non-lead ammunition program is supported in part by the Heritage Fund, a voter-passed initiative started in 1990 to further conservation efforts in the state, including protecting endangered species, educating children about wildlife, helping urban residents to better coexist with wildlife, and creating new opportunities for outdoor recreation. Funding comes from Arizona Lottery ticket sales.
Participation in the non-lead effort has jumped more than 40 percent from its initial levels in 2005.
This effort, spearheaded by the Arizona Game and Fish Department, has earned the support of local hunting groups, including the Arizona Deer Association, Arizona Elk Society, Arizona Antelope Foundation, Arizona Desert Bighorn Sheep Society, and the Arizona Chapter of the National Wild Turkey Federation.
The condor is the largest flying land bird in North America. The birds can weigh up to 26 pounds and have a wingspan of up to 9 1/2 feet. Condors were first reintroduced in Arizona in 1996, and they now number 66 in the state. Visitors at the Grand Canyon and Vermilion Cliffs may be able to observe the birds, especially during the spring and summer.
The condor conservation program began in the 1980s, when the world's population of California condors fell to just 22. Currently, there are 327 condors in existence, with 169 of them flying free in Arizona, Utah, California and Mexico. The Peregrine Fund oversees the recovery program in Arizona, which began in 1996. The organization breeds and raises condors at its World Center for Birds of Prey in Boise and releases the birds to the wilds of Arizona.