The Sumba hornbill (Rhyticeros everetti) is an extraordinary avian species belonging to the Rhyticeros genus within the Bucerotiformes order. This bird finds its home on the Lesser Sunda Islands, particularly the island of Sumba. Adorned in a full black plumage with a long tail, the Sumba hornbill stands out with its distinctive features. This endemic species is native to Indonesia.
With an average length of about 55 cm, the male Sumba hornbill boasts a pitch-black plumage covering its entire body, including the head and neck. Its long tail is similarly black, adorned with a glossy green stripe on the upper wings. The male’s head and neck are characterized by rough feathers, while a darker patch graces the crown and nape of the head. The bare skin surrounding its eyes and throat showcases a light blue hue, contrasting the dark central patch on its back. The male’s large beak is pale yellow with reddish-brown bumps near the base, and it features a “horn” with deep parallel grooves forming the upper layer of this unique feature. The male’s eyes shine in vibrant red, complemented by slightly pink eyelids. Its legs and feet are of a dark gray hue.
In comparison, female Sumba hornbills sport an overall black plumage, including their head and neck, albeit with a smaller body size than their male counterparts. The young birds resemble adult males but possess a smaller bill and lack the distinctive “horns.”
Sumba hornbills are endemic to the Lesser Sunda Islands in Indonesia. They primarily inhabit semi-evergreen forests, areas with deciduous trees, secondary forests, and regions with fruit trees. These birds often prefer lowland habitats and can be found at altitudes of up to 950 meters.
Known for their unique call, the Sumba hornbills produce a sequence of quick “kokokokokok” notes, often compared to a boisterous laugh. They also emit a short “erm-err” sound.
Sumba hornbills predominantly feed on fruit, especially figs, rich in calcium. They occasionally consume large insects and earthworms. Notably, they move in long jumps using both legs and tend to live in pairs or small family groups. At night, they gather in large flocks for safety, returning to the same sleeping spot each evening, with flocks comprising up to 70 individuals.
Monogamous by nature, Sumba hornbills nest in natural tree cavities, usually situated 10 to 23 meters above the ground. The female creates a clay-like mixture using her own droppings, fruit, and feathers, plastering it over the nest’s entrance, leaving a small slit for food passage. Before nesting, the pair establishes a territory and protects an area around the nest. The male often provides courtship offerings at the entrance to the nest. After laying eggs, the female seals herself in the nest, while the male supplies food to both the mother and the young through an opening in the nest’s door. While details about incubation and chick care remain unknown, hatchlings typically lack feathers, are eyeless, and have ruddy skin that turns black within a week of age.
