The birds of this genus are notorious for laying their eggs in other birds' nests

Cacomantis comprises a fascinating group of cuckoo species known for their widespread presence across various island nations and continents, particularly within the Australasian region. These birds exhibit a wide range of behaviors and adaptations that allow them to thrive in diverse environments, from the open woodlands and spinifex plains of Australia to the mangroves and lush gardens of Fiji, New Caledonia, New Zealand, New Guinea, Vanuatu, and the Solomon Islands.

Cacomantis species are versatile in their habitat preferences, often found in drier regions where their cryptic plumage blends seamlessly with the surroundings. This camouflage is crucial for their survival, as it aids in evading predators and stealthily approaching their prey. They are adept at navigating various landscapes, including scrublands and open woods, where their primary diet of insects is abundant. The birds play an essential role in controlling insect populations, as they voraciously feed on grasshoppers, beetles, caterpillars, and other larvae.

An intriguing aspect of Cacomantis cuckoos is their breeding strategy. They are brood parasites, meaning they do not construct their own nests. Instead, they lay their eggs in the nests of other bird species, a behavior that has evolved over millions of years. The unsuspecting host birds incubate the cuckoo eggs and rear the chicks as their own, often at the expense of their offspring. This strategy relieves the cuckoo of the energy demands of rearing young, allowing them to focus on other survival activities.

The breeding season of Cacomantis cuckoos varies depending on the location. In regions with distinct seasonal changes, their breeding activities are often synchronized with those of the host species to ensure the successful parasitism of nests. Cuckoo chicks may outcompete their nestmates for food and may even eject them from the nest to monopolize parental care.