
A radiograph of a common loon showing a lead sinker (the brightest white object) in its gizzard. Photo courtesy of Avian Haven.
One of my not-so-glamorous duties as a wildlife biologist in our agency’s Bird Group is to collect dead loons and send them to the Tufts School of Veterinary Medicine’s Wildlife Clinic to be necropsied (a necropsy is an autopsy of a wild animal). Dr. Mark Pokras and his students determine the cause of death as part of an ongoing study, and then let me know so I can inform the concerned citizen who originally notified me or a coworker of the dead loon. I just finished cataloguing, bagging, and freezing 2 loon chicks and 5 adults. With the help of Avian Haven, a wild bird rehabilitation facility in Freedom, we were able to get radiographs of a few adults – 2 individuals showed obvious lead sinkers in their gizzards. These were both adults, most likely breeding adults, that were otherwise healthy. A sad twist of fate presented them a lead sinker instead of an ordinary stone to add to the numerous stones already in their gizzard used for grinding food. It doesn’t take much lead to cause lead poisoning, and death is only a few days away.