Montagu's harriers breed in lowland cereal crops across Europe, making them uniquely dependent on farmer cooperation to protect nests from harvesting machinery.
Harvest machinery kills chicks and destroys nests if farmers are not warned. Chicks not yet fledged at harvest time face certain death without nest protection. Adults returning from migration to find their nesting field harvested face stress of finding alternative sites. Pesticide reduction of prey affects chick feeding success. Sahel drought in wintering areas causes starvation reducing adult survival rates.