I will never forget in 1985 when a beautiful adult Trumpeter Swan died in my arms as I was attempting to treat it for lead poisoning. It infuriated me that the bird had overcome strong selection pressure only to succumb to ingesting toxic lead pellets expelled from hunter's shotguns in the bottom of the lakes and swamps.
Over the years I saw many cases and began to diagnose it as a common ailment in Bald Eagles as well. Unlike ducks, geese and swans that get lead poisoning from ingesting the lead shot from the pond bottoms, eagles get lead poisoning by ingesting the lead in the muscles of crippled unretrieved waterfowl. When the eagle swallows the muscle of the ducks with the lead pellet they don't have the dexterity of their tongue to spit out toxic pellets and swallow them along with the duck muscle. Eagles have a very acidic stomach which dissolves the lead releasing it to be absorbed.
In a cooperative study with the Canadian Wildlife Service we found that 30% of Bald Eagles had been exposed to lead and 10% of the eagles had toxic levels of lead in their system. Studies such as these aided in the early 1990's nation-wide ban on the use of lead shot in waterfowl hunting.
I triumphed over the victory for wildlife and we saw an immediate decline in the number of lead poisoned wildlife brought to our veterinary hospital. Last week, I revisited past memories of lead poisoning. A mature male Bald Eagle was presented weak and unable to fly. X-rays revealed small metal fragments in the digestive tract. Symptomatic treatment was initiated and a diagnosis of lead poisoning was confirmed.
When the battle of lead poisoning was being fought many hunters opposed the change due to myths and misconceptions about lead shot's replacement steel shot. Most of the hunters did not want to be responsible for wildlife poisonings and went to steel shot but some refused to change over. I wish these non-compliant hunters would watch as lead poisoned eagles and waterfowl suffer from the ingestion of their toxic shot…..they would want to change to steel shot right away.
