Paicines
– Tests have shown that five of the 11 free-flying condors from
the Pinnacles National Monument have elevated levels of lead in
their bloodstream. One of the birds was so sick as to warrant
emergency care, causing scientists to be increasingly concerned
about the safety of the food these birds a
re finding in the wild.
Paicines – Tests have shown that five of the 11 free-flying condors from the Pinnacles National Monument have elevated levels of lead in their bloodstream. One of the birds was so sick as to warrant emergency care, causing scientists to be increasingly concerned about the safety of the food these birds are finding in the wild.
“It peaks during hunting season and breeding season for the small animals, but there is always a threat of lead in the environment,” said Carl Brenner, Supervisor of Interpretation and Education for the Monument. “So we’ve been subsidizing their food all year long.”
Despite their large size, condors are scavengers and feed almost exclusively off carrion. Landowners on property neighboring the Pinnacles often shoot squirrels, rabbits, wild pigs and other animals to maintain the population control, but if they use lead bullets condors can become poisoned when they eat the carcass. In large enough doses, the lead will eventually paralyze and kill the bird.
Pinnacles staff discovered the birds may have ingested lead in mid-June, shortly after receiving the good news that two of their condors had made contact with a larger flock in Big Sur. In order to test their blood levels, the condors were captured with a device Brenner described as “a very elaborate dog kennel,” and four were found to have levels between 30 and 51 micrograms of lead per deciliter of blood.
One condor, No. 307, had more than 60 micrograms in her system and was given six “chelation” treatments – injections of calcium that help the condor’s body flush out the poison. Condor 307 will be held for two weeks to ensure that her blood lead level decreases before she is re-released.
Monument officials are unsure why 307’s blood levels were substantially higher than her cohorts.
“We do know that when we were rounding up the other condors, she got spooked and went to the San Luis Reservoir, so who knows what she could have eaten on the way,” said Brenner. “But we think that at one time, all of these birds might have had lead levels that high, and we would have seen that if we had captured them earlier.”
Though the other four condors were released, they may not be out of the woods entirely, officials say. Lead can be absorbed into the condors’ bones and cause long-term problems, especially if the bird ingests more lead. Precious little information about what those effects could be is available, however, as the effects of lead exposure on condors is only measured in mortality rates.
“We just don’t know what will happen and we have to wait and see,” said Brenner. “But if a human child has a lead level of 10 or 12 we see that as serious and they receive serious treatment, and these condors are in the same state. They’re juveniles. So we have to wait and see if they function normally as adults.”
Pinnacles officials have asked nearby hunters to use copper ammunition, which does not break into small pieces, as opposed to lead, and have links on the Monument Web site to vendors that will supply it. However, no copper ammo is available for a gun as small as a .22-caliber rifle, which is the gun most people use to kill small creatures like squirrels.
“They’re a bit more expensive and they’re a little harder on the barrels,” said Chris Ketchum, foreman of Paicines Ranch, an operation that has chosen to go with the copper bullets. “But we have them (condors) here at our place, so it doesn’t hurt much to take the next step.”
Ultimately, monument officials are pleased with ranchers’ reception to the condor reintroduction program and believe that getting the word out about the dangers of lead to the giant birds is the best way to ensure their survival.
“No one is more excited about the condors than the ranchers. We get calls all the time saying, ‘Hey they’re here on my property,’ or offering to help us,” said Brenner. “We just have to make sure there’s a dialogue going on what we can all do to protect them.”
Danielle Smith covers education for the Free Lance. Reach her at 637-5566, ext. 336 or
ds****@fr***********.com
