4-aminopyridine poisoning of crows in the Chicago area.

Poisoning of crows with the avicide 4-aminopyridine is reported. Seven crows had frequent vocalization and nervous signs; 6 died. Postmortem examination of 4 found evidence of trauma and corn-based bait present in the gastrointestinal tract. The bait contained 4-aminopyridine, a rapidly fatal nervous system toxin. When utilized by pest control professionals using manufacturer's recommendations, 4-aminopyridine has little risk of direct or relay toxicosis to non-target species. Treatment of exposed individuals involves symptomatic care and control of seizures.