How do the bills of ground cuckoos and coucals help them capture prey?

In the cuculiform order, the bills of ground cuckoos and coucals are characterized by being quite stout. This robust structure serves as a formidable weapon, allowing these birds to effectively subdue their prey.1

These larger cuckoos, which include roadrunners, rely on this physical adaptation to capture and consume a diet that consists of substantial numbers of small vertebrates, such as lizards and snakes, in addition to insects.21