North America’s largest bird is on the verge of extinction, and scientists are using shock therapy to give them a fighting chance. The California condor’s wings stretch nearly 10 feet across to help them glide atop air currents while they search for a meal to scavenge. Power lines are a formidable foe for these birds because their large size makes it easier for them to be electrocuted. Now, with fewer than 500 California condors remaining, researchers are administering gentle shocks to teach the birds to avoid these dangerous obstacles.

A Big Bird Problem

It’s common to see birds sitting atop power lines unharmed. That’s because it’s safe to touch a single line, but touching two at a time can be fatal. California condors' large size means they are much more likely to strike two lines at a time. So scientists at the San Diego Zoo Safari Park are hoping to increase California condors’ power line awareness by constructing faux power lines in training pens that gently shock the birds to instill an aversion to power lines. Researchers started placing training power lines in condor sanctuaries at the zoo, and the birds learned to avoid the cables after receiving a few zaps. According to a study published in Biological Conservation, 66 percent of untrained condors released from the sanctuary died of electrocution, but that number dropped to 18 percent with training by 2011. “Utility lines are not a significant problem anymore,” Bruce Rideout, one of the study's authors, told New Scientist. And when trained condors are reintroduced into the wild, they’ll pass down an aversion to power lines to their offspring that learn their flying skills from mom. Researchers at the zoo are already seeing condor chicks follow their parents' lead in the sanctuary.

Not Done Yet

During the 20 ^th century, the California condor population dipped to just 22 birds. An aggressive conservation program, which started in 1988, helped bring the birds’ numbers back up to about 435. Still, California condors face an uphill battle before they fly off the endangered species list. Human activities — power lines and habitat destruction, for example — have caused a lot of trouble for condors. However, hunters’ kills pose the greatest threat. Condors scavenge the carcasses that are left behind after a hunt, but the lead bullets remain in the animal's body. Condors, as a result, get lead poisoning from eating the ammunition that remains in the carcass. The California condors’ comeback isn’t complete, but learning to navigate in a world rife with man-made obstacles could give them a fighting chance.

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