Breakdown: Why lead contamination is threatening Bald Eagles

Published: Jul. 9, 2021 at 12:04 PM CDT
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MEMPHIS, Tenn. (WMC) - Lead poisoning is a leading concern for a number of bird species, including Bald Eagles.

Millions of birds across the United States, including bald eagles, are poisoned by lead every year, according to the American Bird Conservancy.

Hunters use lead bullets to kill deer and other animals.

This presents a significant threat to Bald Eagles as this species’ diet primarily consists of fish, waterfowl, and carrion. Eagles frequently scavenge carcasses of deer, pheasants and other wildlife that may harbor lead or lead fragments.

When ingested in large enough quantities, lead has detrimental effects on the nervous and reproductive systems of mammals and birds. Eagles with lead poisoning may exhibit loss of balance, gasping, tremors and impaired ability to fly. Emaciation follows and death can occur within 2 to 3 weeks after lead ingestion.

Lead poisoning is a national problem, and multiple studies have noted a correlation between big game hunting season and an increase in lead-poisoned birds, according to the Wildlife Center of Virginia.

The Raptor Center at the University of Minnesota has collected volumes of data with alarming statistics regarding the issue and actually produced a video highlighting the torture these eagles go through when being poisoned by lead. Their clinic admits over 150 injured and ill bald eagles each year. On average, 25-30% of these eagles are documented to have lead toxicity.

Depending on the severity of the poisoning, some eagles survive after veterinarians use chelation therapy, injecting the birds with a drug that allows the toxins to be removed from their bodies. Still, many die despite treatment.

Those in too much pain are humanely euthanized to alleviate their extreme suffering.

Lead has no known biologically beneficial role. In 1978, the U.S. Consumer Product Safety Commission banned lead paint in residential and public buildings as well as in toys and furniture, and in 1996 it was banned from use in gasoline.

In 1991, it was banned for waterfowl hunting; however, lead is still a leading metal used in the ammunition for upland hunting, shooting sports and in fishing tackle.

Despite substantial scientific evidence linking the use of lead ammunition to a host of environmental and public health threats, roughly 90 percent of the 10 billion rounds purchased every year in the United States still contain lead, according to Undark.

The Bald and Golden Eagle Protection Act, established in 1940, prohibits possessing, selling or hunting bald eagles. Federal, state and municipal laws continue to protect these animals even after they were removed from endangered animal lists in 2007.

There are primarily two types of lead alternatives for bullets on the market. One has a 100% copper core and the other is a copper mix (95% copper and 5% zinc).

According to the New York State Department of Environmental Conservation, these bullets expand similarly to lead-core bullets, but without all the fragmentation. These non-lead bullets give you the stopping power of lead, as the rapid expansion provides the hydrostatic shock needed to give a quick kill. But because they don’t break apart, non-lead bullets continue to travel through the target further disrupting tissues and breaking bones adding to the stopping power.

In addition, the non-lead bullets typically will pass through the animal leaving an exit wound close to twice the diameter of the entrance wound. This results in greater blood loss and a better blood trail for hunters.

Many companies now produce non-lead center-fire rifle bullets including Barnes, Hornady, Remington, Winchester, Federal and Nosler.

Additionally, the state of California has won the battle against lead ammunition! As of 2019, California is lead-free, and hunting will no longer pose the threat of lead-poisoning of Bald Eagles and other raptors in that state.

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