Blue Ridge Wildlife Center, one of the largest wildlife veterinary hospitals in the Mid-Atlantic, has recently taken in numerous eagles and other raptors suffering from lead poisoning. Currently, the Center has four eagles in its care, three were found in Stafford County and one was found in Loudoun County. They all have abnormally elevated lead levels with lead poisoning being the primary cause of admission in three cases. While the lead levels are decreasing, the birds have a guarded prognosis since high lead levels can cause organ damage.
“Wildlife centers across the state and around the nation are seeing numbers of raptors come in with high lead levels,” said Blue Ridge Wildlife Center Director of Veterinary Services, Jennifer Riley, DVM. Riley has written numerous articles on the lead issue. And, it’s not just eagles, BRWC has found lead in vultures, hawks, and scavenging mammals like opossums as well. “There are reports of greater than 120 avian species being affected by lead poisoning,”Riley explained. “Even low levels of lead, though not causing overt signs, may still cause disorientation such that the animal flies into a car, building or other object.” Last winter, Riley and her team tested all scavenging raptors that came into the Center regardless of clinical signs. Over 90% of eagles and 85% of vultures had some level of lead in their blood.
“Many research groups have looked at the positive correlation between hunting season and lead toxicity cases in wildlife and there has been a significant correlation,” Riley continued, “Radiographs and necropsies performed at wildlife centers all over the country frequently prove that lead ammunition has been ingested.”
It’s very important to note that hunters and their families also eat this lead-contaminated meat which is a threat to their health. One study revealed that 80% of processed deer meat shot with lead core ammunition contained lead fragments (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0005330). There is no safe level of lead intake for animals or humans.
In 1991, there was public outcry when it was learned that nearly four million waterfowl in North America were dying each year from lead poisoning. Waterfowl were ingesting bits of lead they found while filter feeding on the bottoms of marshes, wetlands and other bodies of water. The lead fragments ingested were mainly shotgun pellets that had missed their primary target and rained down into the water. The use of lead sinkers in fishing was also an issue.
After years of debate, the federal government passed a ban on the use of lead shot for waterfowl hunting. The use of lead remains legal to hunt upland species of game. While many hunters assume that the presence of entry and exit wounds in an animal means the bullet, or other projectile, has just passed through and is not a threat, it often is a problem. In nearly every case, traditional lead-core bullets (even those jacketed in copper) will fragment or break apart leaving as much as 30% of the lead in the target animal, especially if they hit something hard like bone. Because the fragments left behind are often so small, many hunters underestimate the significance. Fragments, not visible to the human eye have been found as far as 18” from the wound channel. Tiny fragments of lead can be deadly if ingested by scavenging birds or other animals.
Unfortunately, lead hunting ammunition is still widely used and the Humane Society of the United States estimates that 10 to 20 million non-target animals die each year in this country from lead poisoning.
With the successful recovery of raptors such as the Bald Eagle, the once-endangered bird has seen decreased habitat and has been forced from living close to major bodies of water to moving into habitats where it is more difficult to find food. Many are consuming fragments from lead-based ammunition that are left in parts of animals that remain in the field. In some cases, deer are left in the field after being shot, running away from a hunter and not being found. In other cases, the deer are dressed in the field by the hunter and parts of the animal are left behind. Eagles and other raptors scavenge on these and ingest lead fragments.
Frequently, radiographs of raptors show lead shot or bullet fragments still in the bird’s digestive tract. No level of lead is considered to be safe and, once lead enters the gastrointestinal tract, it remains virtually forever accumulating in the bones and continuing to have a negative impact. If the bird is exposed to additional lead over its lifetime, the toxin will increase and affect the bird’s ability to survive. Cumulative impacts can last over years and only get worse over time. “Unfortunately, we’ve had rescued birds brought to us that have succumbed to lead toxicity despite treatment. These had severe levels of lead and some degree of organ damage,” Riley said.
“Most hunting manufacturers now offer non-lead shotgun and rifle ammunition that are equal or superior to their lead counterparts and comparably priced” Riley stated. “The answer to the problem is for hunters to either use non-lead ammunition or to be sure to completely bury the remains of any parts of the animal they leave behind.”
“At Blue Ridge Wildlife Center, we respect the rights of gun owners and the long tradition of hunting in this country. We firmly believe that no ethical or responsible hunter wants to be responsible for the death of eagles or other non-target animals. As such, we are committed to educating hunters, and the public, on the dangers of lead ammunition” Riley stated.
Blue Ridge Wildlife Center takes in over 2,200 animals each year. The Center is a training facility for other wildlife veterinarians and provides education outreach and on-site programs for school children and adults throughout Northern Virginia. For more information, visit www.blueridgewildlifectr.org.