The Indian grey hornbill (Ocyceros birostris) belongs to the family of hornbills, Bucerotidae.
These hornbill species are distributed in the Indian subcontinent, excluding Sri Lanka. The Indian grey hornbill species predominantly eat berries and fruits. These hornbill species are monotypic bird species.
Indian grey hornbill - Overview
- Scientific name: Ocyceros birostris
- Species author: (Scopoli, 1786)
- Synonyms/Protonym: Buceros birostris Scopoli, 1786, Lophoceros birostris, Tockus birostris, Meniceros birostris
- Family: Bucerotidae › Bucerotiformes › Aves › Chordata › Animalia
- Vernacular names: English: Indian grey hornbill, Chinese: 灰犀鸟, French: Calao de Gingi, German: Keilschwanztoko, Spanish: Cálao gris indio, Russian: Индийский серый токо, Japanese: インドコサイチョウ, Tamil: Saambal Iruvaayan
- Other names: Common Grey-Hornbill
- Distribution: Indian subcontinent excluding Sri Lanka
- Diet and feeding habits: small fruits, berries, insects, lizards, rodents, nestlings
- IUCN status listing: Least Concern (LC)
Appearance, physical description and identificationThe Indian grey hornbill (Ocyceros birostris) is a medium-sized bird, measuring 50 to 60 cm in length and weighing about 370 to 400 grams. The overall plumage of these hornbill species is grayish. The supercilium is pale and grayish. The base of the large bill, ear coverts and casque are dark. The tip of the tail is whitish with a dark subterminal band.
The lower half of the curved bill is pale yellow. The casque is short and pointed. The tail is long and appears graduated. The irises are dark red and the eyelids have eyelashes. The feet are grayish. The hornbill call is a high-pitched penetrating squealing sound.
|Picture of Indian grey hornbill - Ocyceros birostris|
|Image of Indian grey hornbill - Ocyceros birostris|
|Photo of Indian grey hornbill - Ocyceros birostris|
Origin, geographical range and distributionThese hornbill species are distributed in Indian mainland, northeast Pakistan, southern border of Nepal and northwest Bangladesh.
In India, these grey hornbill species occur in the states of Gujarat, Rajasthan, Haryana, Punjab, Uttar Pradesh, Uttarakhand, Himachal Pradesh, Jammu and Kashmir, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Odisha, Maharashtra, Telangana, Andhra Pradesh, Karnataka, Kerala and Tamil Nadu.
The Important Bird and Biodiversity Areas (IBA) of the Indian grey hornbill species in Nepal are Sukla Phanta Wildlife Reserve, Parsa Wildlife Reserve, Barandabhar forests and wetlands, Koshi Tappu Wildlife Reserve and Koshi Barrage Ecosystem and habitat, Bardia National Park, Farmlands in Lumbini area, Chitwan National Park and Dharan forests.
Ecosystem and habitatThese Indian grey hornbill species are moderately forest dependent. These species occur in altitudes from 0 to 100 meters. They inhabit various dry savanna and forest ecosystems. They inhabit arable lands, rural gardens, tropical and subtropical forests and dry savanna.
Diet and feeding behaviorThe diet of these hornbill species is mostly small fruits and berries. The fruits and berries of toothbrush tree, bengal currant, Indian ash tree, fig tree and gum karaya are their primary food. They are also known to feed on insects, nestlings and snails.
Reproduction and breeding habitsThe breeding season of the Indian grey hornbill species is from February to June in the Indian subcontinent. These species are monogamous. They nest in tree hollows, preferably on tall trees. The nest is lined by the flight feathers moulted by the female inside the nest.
The female hornbill enters the tree hollow and seals the entrance with its excreta and mud-pellets supplied by the male. A small vertical slit is left for receiving food. Two to four eggs are laid and incubated by the female.
The male hornbill provides food for the female and chicks. The female regrows the flight feathers. When the chick grow big, the female breaks open the sealing and comes out. At this stage both the parents feed the chicks.
Migration and movement patternsThe Indian grey hornbill is a non-migrant, resident bird. Post breeding, the hornbill juveniles may disperse and establish in new locations within the range. They may make local movements for feeding and breeding within their range. Dearth of food may make them lead a nomadic life.
Conservation and survivalThe global population size of the Indian grey hornbill (Ocyceros birostris) has not been quantified. The overall population size of these hornbill species is considered to be stable. Throughout its range it is reported to be widespread and often common. The generation length is 10.3 years. Their distribution size is about 3,020,000 sq.km.
The Indian grey hornbill (Ocyceros birostris) does not approach the thresholds for being Vulnerable either under the range size criterion or under the population trend criterion or under the population size criterion. The impacts posed by the degradation and loss of habitat is the main threat that may endanger the survival of these species.
IUCN and CITES statusThe IUCN (International Union for Conservation of Nature) has categorized and evaluated the grey hornbill species and has listed it as of "Least Concern". CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) status is ‘Not Evaluated’ for the Indian grey hornbill (Ocyceros birostris).
1.Image source: https://commons.wikimedia.org/wiki/File:Indian_Grey_Hornbill_-_Ocyceros_birostris_-_DSC04595.jpg
Image author: Raman Kumar | License: CC BY-SA 4.0
2.Image source: https://commons.wikimedia.org/wiki/File:Indian_Grey_Hornbill_-_Ocyceros_birostris_-_DSC03965.jpg
Image author: : Raman Kumar | License: CC BY-SA 4.0
3.Image source: https://commons.wikimedia.org/wiki/File:Birds_breakfast.jpg
Image author: Ritu1747 | License: CC BY-SA 4.0
Current topic: Indian grey hornbill - Ocyceros birostris.