The bar-headed goose (Anser indicus) is a goose that breeds in Central Asia in colonies of thousands near mountain lakes and winters in South Asia, as far south as peninsular India. It is one of the world's highest-flying birds, known for the extreme altitudes it reaches when migrating across the Himalayas.
Bar-headed geese are large pale grey birds. They are easily distinguished by the black bars on their head from which they get their common name. Both males and females are similar in appearance but males are slightly larger and heavier than females.
Bar-headed geese breed in Central Asia and winter in South Asia, migrating south from Tibet, Kazakhstan, Mongolia, and Russia before crossing the Himalayas. They usually breed near mountain lakes; on wintering grounds, they prefer freshwater marshes, lakes, streams, or river wetlands, as well as mountain grasslands, cultivated fields, or flooded agricultural areas.
Bar-headed geese are social birds that migrate in flocks and nest in colonies of thousands. They fly in "V"-shaped formations and in order to maintain spacing while flying birds communicate with each other visually and vocally. Bar-headed geese are very powerful fliers and have a slightly larger wing area for their weight than other geese, which is believed to help them fly at high altitudes. When on the ground, they walk well and spend most of the day grazing.
Bar-headed geese are herbivores (graminivores, granivores) and feed mainly on grasses that surround lakes where they nest. They also eat corn, barley, rice, and wheat, and occasionally will take mollusks, insects, and crustaceans.
Bar-headed geese are monogamous and form pairs for several years; however, sometimes males may exhibit polygynous behavior in which they mate with other females. Bar-headed geese breed between late April and July. They nest mainly on the Tibetan Plateau in big colonies and during this time females become very aggressive and defend their nests from lower-rank females that try to lay their eggs in the nests of higher-ranking females. Females usually lay 3 to 8 eggs at a time in a ground nest and incubate them around 28-30 days. Upon hatching, goslings are precocial (well-developed) and are ready to leave the nest 1 or 2 days after birth. They fledge at 55 to 60 days old but remain dependent on their parents for another 10-20 days. Young Bar-headed geese usually reach maturity and are ready to breed for the first time when they are 3 years old.
The main threats to Bar-headed geese include habitat loss, overhunting, egg collection, and persecution from farmers as large flocks may damage grain crops. These birds are also vulnerable to avian influenza and suffer from the presence of power lines, particularly those positioned along key flyways or close to nesting sites.
According to the World Association of Zoos and Aquariums (WAZA) resource, the total Bar-headed goose population size is around 52,000 and 60,000 individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List, but its numbers today are decreasing.
Bar-headed geese serve as seed dispersers due to feeding on a wide variety of plants. These birds are also an important food source for predators of their habitat including crows, foxes, ravens, sea eagles, gulls, and others.
