Giant couas are about in length (nearly double the size of
Coua coquereli) and have a blue patch around their eyes, characteristic of the genus and similar to African turacos. As a member of the cuckoo family, they have a reversible third toe and resemble coucals in their method of scrambling through entangled vines for food. Observations indicate that they can climb 10 m (33 ft) high from the ground.
Coua gigas subsists on seeds (
Capurodendron madagascariensis and
Buxus madagascariensis), insects, and some small vertebrates such as
chameleons (
Furcifer spp.). This species is often encountered in large, unlogged gallery forests that lack dense shrub layers, which provides greater mobility and implies a preference for undisturbed forest with tall trees. In logged forests, giant couas usually
glean during dry seasons and more often leap and
sally during rainy seasons. In contrast, they have been found to do the opposite in forested areas (more often glean during rainy seasons and more often probe during dry seasons), which suggests the significant role that environment plays in foraging behaviour. Giant coua tend to use microhabitats in logged forests with a greater canopy cover, and forage in logged
gallery forests with higher canopies than other areas, while avoiding sites with more stems and obstacles . ==Distribution and habitat==