About half of the bald eagles tested in the United States showed signs of chronic lead poisoning, according to a study published on Feb. 17 in the journal Science.

It is reported that the bald eagle, is the American eagle.

While the U.S. bald eagle population has bounced back from the brink of extinction since the pesticide DDT (DDT) was banned in 1972, 46 of the 38 states sampled from California to Florida have rebounded, the Associated Press reported. Harmful levels of toxic lead have been found in bald eagle bones.

Modeling analysis showed that lead poisoning can reduce the number of bald eagles and golden eagles by 3.8% and 0.8% per year, respectively.

Previous studies have shown signs of lead poisoning in bald eagles and golden eagles in parts of the United States, but this study shows that the situation is widespread across the United States, according to the Associated Press.

The researchers found that the two birds had more lead poisoning during the fall and winter hunting seasons, possibly because they ate the carcasses of animals hit by lead bullets.

The wildlife department encourages hunting with lead-free steel bullets, but the practice of hunting birds and large game with lead bullets remain common, according to the Associated Press.

The bald eagle was on the brink of extinction in the 1960s, in part because of the widespread use of the pesticide DDT, which entered waterways and polluted fish, which in turn endangered the bald eagles, which feed on fish.

After DDT was banned and other protection measures were taken, the number of bald eagles gradually recovered, and now there are more than 300,000 in the wild.

Lead is a neurotoxin that can impair the balance and stamina of eagles even in low doses, reducing their ability to fly, hunt, and reproduce. In high doses, lead can cause seizures, breathing difficulties, and death.

The study estimated that lead exposure, also known as lead exposure, reduced bald eagle population growth by 4 percent and golden eagles by 1 percent.

Bald eagles are one of the most famous conservation successes in the United States, and the birds were removed from the U.S. endangered species list in 2007. But scientists say high lead levels remain a problem.

In addition to suppressing eagle population growth, lead exposure also reduces their resilience to future challenges, such as climate change or infectious diseases.

The researchers also found elevated lead exposure levels in the fall and winter, which coincide with hunting seasons in many states. During these months, eagles will feed on piles of animal carcasses and offal left by hunters, often littered with buckshot or bullet fragments.

Laura Hale, chairman of the board of an Oregon nonprofit, said she will never forget a hawk she encountered in 2018 with acute lead poisoning. At the time, she quickly brought the eagle to the clinic after receiving a call from a resident who said an eagle was motionless in the bushes.

An eagle, wrapped in a blanket, cannot breathe properly, let alone stand or fly. "It's a scary feeling when you see an eagle struggling to breathe from lead poisoning," she said, and the eagle began to twitch and died within 48 hours.