It is a truth universally acknowledged that lead is poisonous. It turns out Carleton could use a lead poisoning program for birds in the arboretum. It does not take much for birds to ingest lethal levels of lead. Ducks, loons, and eagles are all susceptible to lead poisoning through lead shot embedded in prey species, ingestion of lead fishing weights, or consumption of fish who have swallowed lead sinkers. Mallards and loons, in particular, eat sand and rocks to help them grind up their food but cannot tell the difference between rocks and lead sinkers. It only takes one such sinker the weight of a penny to cause death in a bird. Lead damages red blood cells and travels through the bloodstream causing tissue, bone, organ, and neurological damage. Lead poisoned birds often suffer from paralysis, seizures, blindness, and emaciation. Death is likely. Furthermore, the toxic effects of lead may be passed through the egg, increasing chick mortality. Treatment is prolonged, often incompletely effective, and can cost thousands of dollars. This is a substantial stretch for most non-profit wildlife preservation centers.
The grim picture I have painted of lead poisoning in birds is avoidable. Non-lead shot and tackle are available! Using these supplies helps keep lead out of the environment. Additionally, supporting legislation banning lead shot and tackle helps protect our birds. Though such legislation to entirely ban lead has been introduced in Minnesota it has never passed. Picking up after yourself and others similarly keeps lead out of the environment and out of birds’ systems.
Clara Hazlett-Norman ’18, for the Cole Student Naturalists
Photo Caption: X-ray of a Common Loon admitted to the Northwoods Wildlife Center. The highlighted white circles in the abdomen are lead sinkers or fragments.
Photo Credit: Northwoods Wildlife Center