 Northern species such as yellow-billed and black-billed cuckoos are strong migrants, wintering in Central or South America, and occasionally wander to western Europe as rare vagrants, but the tropical "Coccyzus" cuckoos are mainly sedentary.These are vocal species when breeding, with persistent and loud calls.They feed on large insects such as cicadas, wasps and caterpillars (including those with stinging hairs or spines which are distasteful to many birds).