By any measure, the half-century campaign to restore America’s bald eagle population has been a success. In 1970, 20 pairs of nesting bald eagles were counted in Virginia. At present, more than 3,000 active nests are confirmed.

The Wildlife Center of Virginia in Waynesboro has documented the recovery, noting that America’s bird recovered mostly because of two pesticide bans, first on DDT and later on carbofuran.

Now, however, a new threat has appeared: lead poisoning, which the wildlife center terms “one of the most significant threats bald eagles face.”

The center receives sick and injured eagles for rehabilitation, and says that “Many of the eagles … arrive with dangerous levels of lead in their bloodstream” although not from being shot. The eagles, the center said, are scavenging other animals that have been shot with lead-based ammunition.

Treatment consists of chelation, a procedure to flush lead from an eagle’s system. It’s not always successful, the center said, bec...