The summer of 1995 was characterised by consistently high temperatures, leading to severe outbreaks of botulism in many marshlands. In the Markiezaat, a marshy area in the southwestern Netherlands, it was estimated that at least 4% of 10,000 birds had died of botulism in August 1995. In this area, some 8-12 pairs of Marsh Harriers bred. At least 3 dead or dying Marsh Harriers were found, one of which showed signs typical of botulism. Two other harriers were observed eating from maggot-infested corpses of waterfowl.