Cerebellar abnormalities typical of methylmercury poisoning in a fledged saltmarsh sparrow, Ammodramus caudacutus.

A fledged, 12-15 day-old saltmarsh sparrow, Ammodramus caudacutus, was collected from an accidental kill on Cinder Island, Long Island, NY, USA. The sparrow was assessed for feather mercury levels and the brain analyzed for cerebellar abnormalities by microscopic examination. In humans, fetal Minamata disease is caused by maternal ingestion of mercury. It is characterized by disrupted and disordered cerebellar neuronal migration in the fetus or infant. Results from this sparrow show cerebellar abnormalities typical of Minamata disease. It is the first known avian or mammalian specimen taken from the wild to show the abnormalities typical of the human fetal syndrome.