Avian scavengers that typically include game birds and mammals in their diets are at risk of lead poisoning from ingestion of carcasses with fragmented or residual lead ammunition that is used in hunting. Thus, lead may be one of the threats that the griffon vulture ( Gyps fulvus ) faces in the Iberian Peninsula and particularly in Portugal, where their conservation status is considered to be near-threatened. This is the first report that details 3 cases of lead poisoning, associated with the ingestion of lead shot, in adult female griffon vultures found in the Iberian Peninsula. The birds were found prostrate and immediately transferred to a wildlife rehabilitation center, where they died within 24 hours after supportive treatment. Necropsy and histopathologic examinations were done in 2 birds and metal analyses were done in all birds to determine the birds' causes of death. In one vulture, 9 uneroded lead pellets were recovered from the stomach, and moderate to severe hemosiderosis was seen histologically in the liver, lungs, and kidneys. Diagnosis of lead poisoning was confirmed by results of metal analyses, which revealed extremely high lead concentrations in blood (969-1384 μg/dL), liver (309-1077 μg/g dry weight), and kidneys (36-100 μg/g dry weight) for all 3 vultures. To prevent lead poisoning in vultures and preserve their populations in the Iberian Peninsula, more resources are needed for diagnosis and treatment of wildlife in rehabilitation centers, new regulations enabling the abandonment of fallen stock in the field must be approved, and lead ammunition must be prohibited in big-game hunting.
Keywords: Gyps fulvus; Iberian Peninsula; Portugal; avian; griffon vulture; hunting; lead pellets; lead poisoning; toxicosis.