Cuckoos are declining significantly across Europe, with satellite tracking revealing welfare threats along migration routes through the Sahara and sub-Saharan Africa.
Long migration flights across the Sahara require enormous energy reserves; poor pre-migration body condition leads to failure to cross. Shooting during migration causes traumatic mortality. Climate-driven drought in African wintering areas reduces food availability. Host species declines reduce parasitoid opportunities affecting reproductive success. Young cuckoos must migrate entirely alone without guidance, making them particularly vulnerable.