### Identification The Diederik Cuckoo (*Chrysococcyx caprius*) is a shimmering emerald jewel of the African bush. Measuring about 19cm, the adult male is unmistakable with his brilliant metallic-green upperparts and a distinctive white stripe running behind the eye. His underparts are snow-white, marked by bold green barring on the flanks. Look for the white spots on his wing coverts and tail tips—key field marks that distinguish him from the similar Klaas’s Cuckoo, which lacks the extensive white wing spotting. Females are more copper-bronze and often exhibit rufous barring on the wings. Both sexes possess a striking, ruby-red iris that glows when caught in the sunlight.
### Habitat & Range This species is a common intra-African migrant, found across Sub-Saharan Africa and parts of the Arabian Peninsula. It thrives in open woodlands, acacia savannas, and lush suburban gardens. You’ll rarely find them in deep, closed forests; they prefer "edge" habitats and riverine scrub where their preferred hosts—weavers and bishops—nest in high densities.
### Behaviour You will likely hear a Diederik before you see it. Its persistent, plaintive whistle—*dee-dee-dee-deederik*—is the soundtrack of the rainy season. Males are highly conspicuous, calling from the tops of trees to defend territories. As a brood parasite, it doesn't build its own nest. Instead, it is a master of deception; the female monitors host nests (like the Southern Masked Weaver) and, in a blurred few seconds, swoops in to replace a host egg with her own.
### Diet The Diederik is a specialist of the "unpalatable." It primarily gleans hairy caterpillars from foliage—prey that most birds avoid due to toxic bristles. They are also known to take other insects, like termites and grasshoppers, and occasionally consume the eggs of their host species during their parasitic raids.
### Fascinating Fact The Diederik Cuckoo is a genetic specialist! Individual females belong to specific "gentes" (lineages), meaning a single female will only parasitize the specific host species that raised her. Evolution has honed her eggs to perfectly mimic the color and pattern of that specific host's eggs, making her botanical forgery nearly undetectable.