[6] The plumage of the head, neck, back, wings and upper breast is black with a slight green sheen.

[5][6] Casques of mature oriental pied hornbills are laterally flattened “cylinders”, which may form a protruding horn.

Males can be distinguished from females by their larger body size, yellow bill, which has a black base, and bright red eyes.

Females have a slightly smaller body size, a yellow bill and casque with a partly black, browned patched mandible, and grayish-brown eyes.

[2] Its range encompasses eastern and northern India, Nepal, Bangladesh, Bhutan, Tibet, Myanmar, Thailand, Laos, Cambodia, Vietnam, Peninsular Malaysia, Singapore, Indonesia, Brunei and the Sunda shelf islands.

During the non-breeding season, oriental pied hornbills feed more on non-fig fruit such as small sized berries, drupes, arillate capsules and lianas (woody vines), however the availability of these food items is lower in the breeding season, which suggests that the species increases its habitat range during that time.

[2] Other target species include Rourea minor, Polyalthia viridis, Cinnamomum subavenium, Trichosanthes tricuspidata, and many others.

[2][7] Hornbills are secondary cavity nesters, meaning that they typically do not excavate their own nesting sites but use those created by other birds or by branches breaking off.

[7][12] Because hornbills rely on pre-excavated cavities, selection of suitable nest-sites within their environment has major impacts on breeding success.

[12] When females have selected and entered their nest, they seal the cavity with a mixture of saliva, mud, fruit, droppings and tree bark, leaving only a small opening through which food may be passed in.

[12] Some oriental pied hornbills have demonstrated tree species preferences for nest site selection.

In Rajaji National Park in India, oriental pied hornbills nest in a variety of tree species such as Bombax ceiba, Careya arborea, Cordia myxa, Lagerstroemia parviflora, Mitragyma parviflora, Terminalia belerica, Shorea robusta, and Syzigium cumini.

Oriental pied hornbills tend to select nesting sites in close proximity to rivers or other bodies of water.

Competition for nest-sites with other species such as squirrels, lizard and other cavity nesting birds can also have critical impacts on breeding success.

What declines in oriental pied hornbill population have been reported are mainly caused by legal and illegal logging, which decreases the availability of suitable nesting and fruiting trees.