There are about 54 species of hornbills in the world, out of which 9 occur in India. The hornbill pictured here is the Indian Grey Hornbill, which is common across the Indian subcontinent, except the wettest (Western Ghats and northeast) and the driest (northwest) parts of the country.

Indian Grey Hornbill, Ocyceros birostris at Pune, Maharashtra

Breeding/Nesting
Hornbills have unique breeding habits, where the female confines herself into a nest cavity in a tree, with only a narrow opening through which the male shares the food throughout the nesting period. For the Indian grey hornbills, the total nesting period is about 87 days, where the female is confined to the nest cavity for an average of 76 days. Most of the grey hornbill nests are in hollows of the Mahagony tree family, located nearby riverine habitats. Deforestation, agriculture and other developmental activities have restricted the range of many species like these hornbills.

Grey hornbills as seed dispersers
Hornbills play a key role in seed dissemination, germination and regeneration of trees. This is because they are mainly frugivores (fruit consuming) and can break up/swallow large fruits, and regurgitate the seeds without damaging, making them the perfect dispersers. Since they travel long distances in search of fruits, they are capable of moving these seeds to distant locations.

Grey hornbills are effective seed dispersers for trees such as Premna tomentosa (a teak like tree), Putranjiva, Fern trees and even Sandalwood trees! Many of these are medicinally and commercially valuable trees but they generate very few seeds and propagation depends on birds like these hornbills.

Mid-air play and fight
Like many other hornbills, the grey hornbill has a long curved bill, which has a casque (helmet) on the top. The male hornbills engage in midair clashes where they jar against each other’s casques to establish their dominance and as part of their social play. This behaviour is known as aerial jousting.

Species: Ocyceros birostris
English: Indian Grey Hornbill
Location: IITM colony, Pune, Maharashtra
Date: 30 Jul 2016

Reference:
1. Santhoshkumar, E., & Balasubramanian, P. (2010). Breeding behaviour and nest tree use by Indian Grey Hornbill Ocyceros birostris in the Eastern Ghats, India. Forktail, 26, 82-85.
2. Santhoshkumar, E., & Balasubramanian, P. (2011). Seed dispersal by the Indian Grey Hornbill Ocyceros birostris in the Eastern Ghats, India. Ecotropica, 17(2), 71-77. 
3. Balasubramanian, P., Aruna, R., Anbarasu, C., & Santhoshkumar, E. (2011). Avian frugivory and seed dispersal of Indian Sandalwood Santalum album in Tamil Nadu, India. Journal of Threatened Taxa, 3(5), 1775-1777.
4. Anbazhakan, S., & Balu, S. (2004). Macropropagation of the Indian Medicinal plant Premna tomentosa Willd. Ancient science of life, 23(3), 34.
5. Kasambe, R., Charde, P., & Yosef, R. (2011). Aerial jousting and bill grappling in Indian Grey Hornbill (Ocyceros birostris). Acta Ethologica, 14(1), 13-15.

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