The Indian gray hornbill (Ocyceros birostris) is a tropical bird that can be found on the Indian subcontinent. It is mostly arboreal and is commonly seen in pairs. It is one of the few hornbill species found in urban areas in many cities where they can make use of large trees in avenues.
Di
DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
Fr
FrugivoreA frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts, and seeds. Approx...
He
HerbivoreA herbivore is an animal anatomically and physiologically adapted to eating plant material, for example, foliage, for the main component of its die...
Ov
OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
Ar
ArborealArboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some anima...
Gl
GlidingGliding flight is heavier-than-air flight without the use of thrust and is employed by gliding animals. Birds in particular use gliding flight to m...
Zo
ZoochoryZoochory animals are those that can disperse plant seeds in several ways. Seeds can be transported on the outside of vertebrate animals (mostly mam...
Mo
MonogamyMonogamy is a form of relationship in which both the male and the female has only one partner. This pair may cohabitate in an area or territory for...
So
SocialNo
Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
I
starts withThe Indian grey hornbill is a medium-sized bird with greyish-brown upper parts and 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. These birds 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.
Indian grey hornbills are found from the foothills of the Himalayas southwards, bounded to the west by the Indus system and to the east by the Ganges Delta. They don't migrate but may make local movements in the drier western region. Indian grey hornbills live in dry forests, savannas, rural gardens, and even in cities that have old avenue trees.
Indian grey hornbills are active during the day and usually spend time in pairs or small groups. 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 have various social activities, including bill-grappling and aerial jousting. Indian grey hornbills are quite noisy producing squealing calls, loud cackling, or short pipping-like sounds. Their flight is heavy and involves flapping interspersed with glides.
Indian grey hornbills are mainly herbivores (frugivores). They feed on various fruits including the fruits of Thevetia peruviana (a poisonous plant) which are toxic to many vertebrates. They can sometimes take mollusks, scorpions, insects, small birds, and reptiles.
Indian grey hornbills are monogamous and form strong pair bonds. They typically breed between April and June and the clutch varies from 1 to 5 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 molts 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 incubation period lasts around 21 days and chicks fledge approximately 45 days after hatching. The regrowth of the female's feathers coincides with the maturity of the chicks, at which point the nest is broken open.
The main threats to Indian grey hornbills include the loss of dry forests along with fruit trees the birds rely on in their diet. They also suffer from hunting in some areas and disturbances due to agricultural practices by locals and livestock grazing.
According to the IUCN Red List, the Indian grey hornbill is common throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
Indian grey hornbills play a very important role in their ecosystem. They disperse the seeds of the fruits they feed on and thus help to regenerate the dry forests.
Social animals are those animals that interact highly with other animals, usually of their own species (conspecifics), to the point of having a rec...