Absorption of hazardous levels of lead into body tissues which disrupts their normal function.

Many migratory bird species, most commonly ducks, geese, swans, and raptors (especially eagles). Less commonly seen in shorebirds, other water birds and upland game birds such as pheasants, quail, and doves.

Ingestion of lead objects such as lead shot, lead fishing sinkers, paint chips and mine wastes. In raptors, poisoning results from ingesting lead shot embedded in the flesh of prey. Lead objects are ground down by the gizzard or dissolved by stomach acids and absorbed into the body as lead salt disrupting normal body functions, especially the digestive and nervous systems of birds.

Lead poisoning is considered a chronic disease in wild birds and sick and dead birds are usually observed in low numbers, if at all. Large scale mortality due to lead poisoning occurs rarely. Birds are often mistaken for cripples during or after the hunting season. Signs include: lethargy, progressive weakness, green-stained feces and vent (cloaca) due to bile staining, a reluctance to fly or inability to sustain flight, and weight loss leading to emaciation. Severely affected birds often do not have an escape response but will usually seek isolation and cover, making them difficult to find. Green-colored feces can be seen in areas used by lead-poisoned waterfowl.

Emaciated birds with severe wasting of breast muscles. Impaction of esophagus and/or proventriculus containing food, sand, or mud. Enlarged gallbladder containing thick, dark green bile. May see bile staining (green color) in the gizzard and/or around the vent. Gizzard may or may not contain lead fragments. These lesions are similar to what is seen in starvation. The diagnosis is confirmed by detecting toxic levels of lead in the liver.

Losses occur nationwide, usually in winter or early spring (after the hunting season). Waterfowl on high corn or grain diets have an increased sensitivity to lead. Identifying the lead source and reducing its availability through discing or reclamation will help minimize losses. Use of nontoxic shot is a good long-term solution for reducing losses.

No appreciable human health risks are associated with occasionally eating meat from lead poisoned waterfowl. Liver, kidney, and bone marrow of birds will contain higher lead levels than meat. Pregnant women and children should consult their physician. Accidental Ingestion of lead shot embedded in meat occurs occasional and may cause lead poisoning or appendicitis.

For additional information on this or any other wildlife health issue, contact the National Wildlife Health Center at (608)271-4640 or FAX (608)264-5431