Lead Poisoning in Raptors and Other Animals

Lead toxicosis is a significant—and preventable—health issue for Bald Eagles and other birds of prey.

Lead is a metabolic poison, a naturally occurring but dangerous element that is known to be toxic to most living things. Ingestion of lead significantly contributes to the admissions of dozens of Bald Eagles, vultures, and other raptors at the Wildlife Center of Virginia each year. Few birds with high levels of lead make a complete recovery. Historically, raptors such as eagles and vultures have been the focus of lead testing, due to their propensity to scavenge. In recent years, the Wildlife Center has expanded testing criteria to include other birds of prey, mammals, and even reptiles. This expanded testing has resulted in more species being diagnosed and treated for lead. 

These exposures primarily result from the ingestion of lead, often in the form of spent hunting ammunition and lead fishing tackle.

What You Should Know

  • How do raptors get lead poisoning? Eagles and other avian scavengers are getting the lead primarily by scavenging the carcasses or remains of animals left in the field by hunters. When shot with lead ammunition, game animals can contain very small pieces of lead, which fragment upon impact with the target. Learn more about how eagles and other birds are exposed to lead.
  • What are the symptoms of lead poisoning in animals? Animals admitted to the Center with visible symptoms of lead poisoning may be lethargic, have muscle wasting, and exhibit overall weakness, as well as show specific central nervous system effects including inability to maintain balance, lack of muscle coordination, or even paralysis. In cases where symptoms are not obvious, smaller measurable levels of lead impair the ability to fly and hunt effectively. Such sub-clinical intoxication is the functional equivalent of driving drunk; the birds are more likely to suffer accidents or injuries that would otherwise be avoidable. Even young raptors are admitted to the Center with detectable lead levels, typically as a direct result of being fed contaminated food from their parents. The Cornell Wildlife Health Lab has an informative page on lead toxicosis, its causes, and symptoms
  • How many animals are exposed to lead? The Wildlife Center of Virginia has treated hundreds of animals suffering from lead toxicosis in recent years. Our best and most consistent data is for Bald Eagles. Because of the extent of the problem in that species, the Center tests every Bald Eagle that enters our doors for blood lead levels. You can read about the results of that ongoing study in The Wildlife Center's Research into Lead in Raptors below. 
  • Resources for hunters. Education and information sharing among hunters will be the most effective avenues to make changes on this issue. The threat of lead poisoning of eagles and other birds of prey can be almost entirely eliminated if hunters voluntarily make one of two simple changes: either switch to non-lead ammunition for hunting, or bury hunting remains that are left in the field. Read more on the Wildlife Center’s Resources for Hunters page. 
Resources to Learn More about Lead

What You Can Do

  • Learn about the issue and have conversations with family and friends who hunt. It’s important to be able to have a positive and respectful conversation; the goal is to educate and inform, not judge or condemn hunting.
  • Reach out to hunter safety instructors in your community to encourage them to become informed about the issue of lead poisoning related to game and animal parts left in the field.  Encourage instructors to add a section to their training course about the proper disposal of animal parts that may contain lead, and to inform their students about the alternatives to lead shot which can eliminate the problem.
  • Contact your local media and provide them with links to the Wildlife Center’s information about this issue. Ask them to investigate the extent of the problem in your area, and report to the public any issues found.
  • Contact local retailers of firearms and ammunition to encourage them to stock and make available a wide variety of non-lead alternatives for hunters.  If hunters are not able to find lead-free ammunition, they cannot use it.  Both hunters and non-hunters can work to be sure it is available.
  • Contact your local rehabilitation centers to determine if they are currently testing for lead in raptors. If not, offer to support and fund efforts to do so, or at least to collect samples for testing by others. If rehabilitation centers need technical advice, they should contact the Wildlife Center of Virginia
eagle with lead poisoning being treated

The Wildlife Center of Virginia's Research on Lead in Raptors

Each year, the Wildlife Center admits dozens of birds with lead poisoning, including eagles, vultures, hawks, and owls. All raptors and waterfowl are tested for lead upon admission; the veterinary team draws blood from each bird and runs it through an in-house lead analyzer for immediate results.

In a 10-year period (2011 - 2021), of the more than 360 Bald Eagles admitted as patients, 271 of the eagles, almost three out of four, had measurable levels of lead in their blood. The only safe level is 0. Of those tested, 26% have had lead levels that are considered “elevated.” The survival rate of the Bald Eagles we’ve treated with elevated levels is 5%. 

Eagles are not the only animals affected. Of the 337 other raptors (various species of hawks, owls, and falcons) tested in the 10-year period, one in three had measurable levels of lead exposure. The Center is now also testing other species for lead, including Virginia Opossums, and some select game birds during hunting season. We've even confirmed some positive cases in reptiles. 

Lead exposure infographic

Frequently Asked Questions about Lead

Q: Can’t we just ban all lead bullets and shot?

A: The challenge is not to find a way to ban the use of all lead—it is to find a way to reduce the amount of toxic lead fragments available to non-target wildlife and to do it without unreasonably affecting those whose activities are otherwise legal and acceptable to the public. Most lead-based firearms ammunition is used for national defense and public safety—by the military and police agencies. Target and competitive shooters, and those who own firearms for self-defense, consume the majority of munitions purchased by the private sector. Hunters use only a small percentage of all ammunition sold in the United States each year. A ban on all lead-based ammo would deal a serious blow to national security and public safety, and would hurt a lot of law-abiding firearms users, who are not contributing to the problem of lead-poisoned wildlife!

Q: What about the recent ban on hunting big game with lead in California – what about THAT kind of ban? Why shouldn’t we ban lead for hunting?

A: The original concern about hunting with lead in California stemmed from a number of endangered California Condors that died from lead poisoning. Initially, the ban was put in place only in the specific areas to which the condors had been reintroduced. Eventually, the ban was extended statewide, for implementation in 2019. Unfortunately, this ban came about in such a way that hunters felt steam-rolled in the process.  Recent surveys suggested that little effort was made to inform and educate hunters or involve them with the conservation effort related to condors. As a result, there are some very hard feelings on the part of the hunting and shooting public—hard feelings that may well have been avoided if a more collaborative approach had been tried. The political reality is that most states have a far more powerful hunting community than does California. In states like Virginia, the right to hunt and fish is actually in the state constitution, so enacting ammunition bans, over the objections of the hunting and shooting public, will not be easily done. This is why the Wildlife Center of Virginia advocates information and education as the first steps toward eliminating this preventable threat.

Q: I have heard that some groups claim that eagles are getting the lead from sources other than bullets. Is this true?

A: There is a lot of published misinformation on this issue. One writer for the National Shooting Sports Foundation implied that condors, vultures, and eagles were getting lead poisoning from sources like discarded car batteries! While people and animals may have some exposure to lead from contaminated water, paint, or other similar sources, the levels of lead being detected in eagles and other scavengers are far too high to be associated with trace amounts of lead in the environment. Multiple studies comparing isotopic compositions of lead found in the bloodstream of Bald Eagles and other scavengers with the lead used in ammunition have confirmed that lead from spent ammunition is the source of this toxicity.

While we’ve never found pieces of a car battery on raptor radiographs, our veterinary team has found many instances of tiny lead fragments in the gastrointestinal tracts of poisoned birds. You can view a series of radiographs of birds with ingested lead fragments in this Wildlife Center photostream.

Q: If a hunter shoots a deer, doesn’t the bullet just pass through the body of the quarry, eliminating any danger of residual lead?

A: Many hunters using rifles or pistols assume that the presence of an entry wound and an exit wound indicates that the bullet or other projectile has passed through the target animal and is gone. However, in nearly every case, bullets will fragment or break apart, especially if they hit something hard, like a bone. Hunting bullets leave behind as much as a third of the original bullet mass in the muscles or internal organs of the target animal, even when the largest part of the bullet passes through. Since most of these fragments are very small, their potential significance is easily overlooked by hunters. Only recently has it been shown that these tiny fragments of lead can be toxic if ingested by scavenging or predatory birds.

Q: Don’t lead sinkers and fishing lures poison birds as well?

A: Yes, there are areas where birds like loons and swans suffer a high incidence of lead poisoning from ingesting lead sinkers that have been broken off of fishing tackle. While this problem is not one frequently seen by the Wildlife Center of Virginia, additional information can be found from several other sources, including EPA

Q: Wasn’t lead ammunition for hunting banned in the ‘90s?

A: Only in waterfowl. Millions of ducks and geese were dying of lead poisoning after they ingested bits of lead they found while filter-feeding on the bottoms of wetlands, marshes, shallow estuaries, or other bodies of water. The lead fragments the birds ingested were mainly shotgun pellets that had missed their primary target and rained down over the water. The birds would deliberately pick up this shot and swallow it, thinking it to be food or grit they need for digestion. After years of debate, the federal government finally enacted a ban on the use of lead shot for most waterfowl hunting. Studies indicate that the ban was successful and significantly reduced mortality in waterfowl. The use of lead and lead-based projectiles for hunting of so-called upland species of game (e.g., quail and pheasants) and nuisance wildlife has remained legal, presumably on the logic that spent shot which falls upon the land is very unlikely to be found and ingested by wildlife.

Q: Why don’t we just ban all hunting?  That would take care of it!

A:  For many people who don’t like hunting, this seems like an easy answer; but the truth is, it’s not that easy. Hunting is not as popular as it once was in the United States, as a greater percentage of our population has gravitated to urban and suburban locations, but it is still an extremely popular pastime. In some states, like Virginia, hunting and fishing are rights guaranteed in the state constitution. And, to some extent, a hunting ban would be like banning driving as a way to reduce traffic accidents—not a proportional response. In truth, many of the leaders of the movement to eliminate lead from hunting ammunition are themselves, hunters. They are often the most effective messengers for information about lead toxicity. Conversely, someone who openly opposes all hunting is NOT the right person to try and educate or inform the hunting public about this issue. It may make you feel good to rant about hunters and declare, “Just shoot the hunters!” but that is actually extremely counterproductive. The issue is about the availability of lead to scavengers, not about whether or not hunting is a good thing.