be excavated further to suit. The female enters the nest hollow and seals the nest hole, leaving only a small vertical slit through which the male feeds her. The nest entrance is sealed by the female using its excreta and mud-pellets supplied by the male. While inside the nest, the female moults her flight feathers and incubates the eggs. The male provides the nest inmates with a steady supply of bark pieces to ensure that the excreta is removed from the nest by absorption and adsorption and to help maintain the micro-climate within the next cavity. The regrowth of the female's feathers coincides with the maturity of the chicks, at which point the nest is broken open. A study at a nest near Mumbai noted that the key fruiting trees on which the hornbills fed were Streblus asper, Cansjera rheedii, Carissa carandas, Grewia tiliaefolia, Lannea coromandelica, Ficus spp., Sterculia urens and Securinega leucopyrus. They are also known to take molluscs, scorpions, insects, small birds (they have been recorded removing and possibly preying on rose-ringed parakeet chicks) and reptiles in their diet They are known to feed on the fruits of Thevetia peruviana, which are known to be toxic to many vertebrates. They are almost completely arboreal, but very rarely descend to the ground to pick up fallen fruits, to dust bathe, or to pick up mud pellets to seal the nest cavity during the nesting period. They indulge in various social activities, including bill-grappling and aerial jousting. Gallery References Indian grey hornbill Birds of South Asia Indian grey hornbill