are generally monogamous and breed between January and June; oriental pied hornbills typically commence breeding in February. This coincides with the onset of rain depending on geographic location, and peak abundance of fruit. 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. Because hornbills rely on pre-excavated cavities, selection of suitable nest-sites within their environment has major impacts on breeding success. 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. The male forages for the female and chicks, and the female feeds the nestlings. Chicks remain inside the nest with the female for several months until there are ready to fledge. Oriental pied hornbills have shown to return to their previous nest for subsequent nesting seasons. Nest selection Hornbills select nest sites based on the availability and type of fruiting trees, as well as on the availability and quality of nest site cavities in their particular habitat. 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. The main difference in the structural characteristics of nest cavities between hornbill species is cavity size, which is highly correlated with body size. Cavities preferred by the oriental pied hornbill are elongate and may be located at a height between 1–18 m or more. Cavity entrance shape is rounder than for other hornbills. Oriental pied hornbills tend to select nesting sites in close proximity to rivers or other bodies of water. Compared to other hornbill species such as the great pied hornbill and wreathed hornbill, the oriental pied hornbill demonstrates tolerance to disturbed habitats. Nests have been found in disturbed, secondary forest areas such as plantations, degraded forests and logging sites, while other hornbill species tend to avoid such sites. Nests found in human disturbed areas are however often unsuccessful or abandoned; in general, hornbills prefer undisturbed forest areas. Because oriental pied hornbills inhabit various habitats, nest structural characteristics may vary from one habitat to another, and may also vary