The Indian gray hornbill (''Ocyceros birostris'') is a common
hornbill found on the
Indian subcontinent
The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...
. It is mostly
arboreal
Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...
and is commonly sighted in pairs. It has grey
feathers all over the body with a light grey or dull white belly. The horn is black or dark grey with a
casque
Casque is a French word for helmet. It can refer to:
* Casque (anatomy), an enlargement on the beaks of some species of birds, including many hornbills
*Hornbill ivory, the casque of the helmeted hornbill, collected as a decorative material
* S. C ...
extending to the point of curvature of the horn. It is one of the few hornbill species found in urban areas in many cities where they are able to make use of large trees in avenues.
Description
The Indian grey hornbill is a medium-sized hornbill, measuring around in length.
The upper parts are greyish brown and there is a slight trace of a pale
supercilium. The ear coverts are darker. The flight feathers of the wing are dark brown with a whitish tip. The tail has a white tip and a dark subterminal band. They have a red iris and the eyelids have eyelashes. The casque is short and pointed.
The male has a larger casque on a dark bill, and the
culmen and lower mandible are yellowish. The bare skin around the eye is dark in the male, but sometimes pale reddish in females. The female has a more yellowish bill with black on the basal half and on the casque.
The juveniles lack the casque, and the bare skin around the eye is dull orange.
Distribution
The species is found mainly on the plains up to about . It is found from the foothills of the Himalayas southwards, bounded to the west by the Indus system and to the east by the
Ganges Delta. It may make local movements in the drier western region. It is found even in cities that have old avenue trees.
[ The species has been observed, usually in pairs, in Dharamsala town (Himachal Pradesh) at about 1500 to 1600 masl during summer and in the rainy season (May to September, 2017). and does not overlap much with the ]Malabar grey hornbill
The Malabar gray hornbill (''Ocyceros griseus'') is a hornbill endemic to the Western Ghats and associated hills of southern India. They have a large beak but lack the casque that is prominent in some other hornbill species. They are found main ...
of the Western Ghats.[
]
Behaviour and ecology
The call is a squealing call somewhat like that of a black kite
The black kite (''Milvus migrans'') is a medium-sized bird of prey in the family Accipitridae, which also includes many other diurnal raptors. It is thought to be the world's most abundant species of Accipitridae, although some populations have ...
. The flight is heavy and involves flapping interspersed with glides. They are found in pairs or small groups.[
The nesting season is April to June and the clutch varies from one to five very symmetrical white eggs. Indian grey hornbills usually nest in tree hollows on tall trees. An existing hollow may 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
Mumbai (, ; also known as Bombay — List of renamed Indian cities and states#Maharashtra, the official name until 1995) is the capital city of the Indian States and union territories of India, state of Maharashtra and the ''de facto'' fin ...
noted that the key fruiting trees on which the hornbills fed were ''Streblus asper
''Streblus asper'' is a tree known by several common names, including Siamese rough bush, khoi, serut, and toothbrush tree. It is a medium-sized tree native to dry regions in Indonesia, Cambodia, Thailand, India, Sri Lanka, Malaysia, and Vietnam ...
'', '' Cansjera rheedii'', ''Carissa carandas
''Carissa carandas'' is a species of flowering shrub in the family Apocynaceae. It produces berry-sized fruits that are commonly used as a condiment in Indian pickles and spices. It is a hardy, drought-tolerant plant that thrives well in a wide ra ...
'', '' Grewia tiliaefolia'', ''Lannea coromandelica
''Lannea coromandelica'', also known as the Indian ash tree, is a species of tree in the family Anacardiaceae that grows in South and Southeast Asia, ranging from Sri Lanka to Southern China. It is commonly known as Gurjon tree and is used in ply ...
'', ''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
The rose-ringed parakeet (''Psittacula krameri''), also known as the ring-necked parakeet (more commonly known as the Indian ringneck parrot), is a medium-sized parrot in the genus Psittacula, of the family Psittacidae. It has disjunct native ran ...
chicks) and reptiles in their diet They are known to feed on the fruits of ''Thevetia peruviana
''Cascabela thevetia'' (syn: ''Thevetia peruviana'') is a poisonous plant native throughout Mexico and in Central America, and cultivated widely as an ornamental. It is a relative of '' Nerium oleander'', giving it a common name yellow oleander, ...
'', 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
Indian Grey Hornbill I2 IMG 9029.jpg, Individual with a shorter casque, either a juvenile or female
Indian Grey Hornbill I IMG 9017.jpg, At Uttarakhand
Uttarakhand ( , or ; , ), also known as Uttaranchal ( ; the official name until 2007), is a state in the northern part of India. It is often referred to as the "Devbhumi" (literally 'Land of the Gods') due to its religious significance and ...
, India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
Indian grey hornbill foraging.jpg, In Janakpur
Janakpurdham or Janakpur ( ne, जनकपुर, ) is a sub-metropolitan city in Dhanusha District, Madhesh Province, Nepal. The city is a hub for religious and cultural tourism. A headquarter of Dhanusha district, ''Janakpur'' is also the capi ...
, Nepal
Nepal (; ne, :ne:नेपाल, नेपाल ), formerly the Federal Democratic Republic of Nepal ( ne,
सङ्घीय लोकतान्त्रिक गणतन्त्र नेपाल ), is a landlocked country in S ...
Indian GreyHornbill.JPG, A pair (female right and male at left) at Mohali, Punjab
Punjab (; Punjabi: پنجاب ; ਪੰਜਾਬ ; ; also romanised as ''Panjāb'' or ''Panj-Āb'') is a geopolitical, cultural, and historical region in South Asia, specifically in the northern part of the Indian subcontinent, comprising a ...
, northern India
References
{{Taxonbar, from=Q223574
Indian grey hornbill
Birds of South Asia
Indian grey hornbill