Cuckoo chicks look similar to their host chicks. Cuckoo chicks (left) and their host "brothers" of different species (right) | Source: Naomi Langmore

Cuckoo chicks look similar to their host chicks. Cuckoo chicks (left) and their host "brothers" of different species (right) | Source: Naomi Langmore

Cuckoo chicks look similar to their host chicks. Cuckoo chicks (left) and their host "brothers" of different species (right) | Source: Naomi Langmore