Gru dal collo nero

Identificazione

This medium-sized crane is mostly grey with a black head and neck. The lores and crown are naked and dull red. A small patch of white feathers are present below and behind the eye. The tail is black and makes it easy to distinguish at a distance from the similar looking common crane which has grey tail.

Tassonomia

Nome scientifico

Grus nigricollis

Autorità

Przevalski, 1876

Ordine

Gruiformi

Famiglia

Gruidae

Genere

Grus

Areale e habitat

The black-necked crane summers mainly in the high-altitude Tibetan Plateau. The breeding areas are alpine meadows, lakeside and riverine marshes and river valleys. They also make use of barley and wheat fields in these areas. Wintering areas tend to be in sheltered valleys or lower altitudes. The largest populations are in China with smaller numbers extending into Vietnam, Bhutan and India. Small populations have been noted in northern Sikkim. A small group of 20 to 40 was once known to regularly visit the Subansiri area in the Apa Tani valley until 1975, and vagrants have been recorded in Nepal.<p>In 1991, an estimated 600 to 900 cranes inhabited the Hongyuan-Ruoergai Plateau, Sichuan, China, making it the most crucial breeding and summering area for the cranes at that time. According to a 2013 survey, the total crane population in the Zoigê Marsh was 893.<p>In 1996, there were about 4,000 of the birds, most of whom spent their winters in Tibet in the valleys of the Nyanga, Lhasa and Pengbo rivers and the middle reaches of the Yarlung Tsangpo.The Hutoushan Reservoir in the Pengbo valley is an important winter resting place, with a 96 square kilometres (37 sq mi) Linzhou Black-necked Crane Preservation Zone established in 1993.Black-necked cranes also winter in small numbers in two valleys of western Arunachal Pradesh, India. These are Sangti and Zemithang.

Areale riproduttivo

PAL : Tibet and wc China

Areale non riproduttivo

n OR

Migrazione

Vertical migration

Comportamento

Black-necked cranes forage on the ground in small groups, often with one bird acting as a sentinel. In winter, the groups arrive and leave the feeding grounds together, but may split into family groups, each group keeping their own small feeding territories in a big marshes or fields. They spend nearly 75% of the day foraging with peak feeding in the early morning and late afternoon. While foraging, they keep walking and they also walk long distances between the feeding spots. In this manner, they cover several kilometers a day while foraging. They feed on the tubers of sedges, plant roots, earthworms, insects and other invertebrates, frogs and other small vertebrates. They may also feed on fallen grains of barley, oats and buckwheat and will sometimes dig up and feed on potatoes, carrots and turnips. Their loud trumpeting calls are similar to those of other cranes.<p>These birds are very wary, but in some areas they are accustomed to the local people who do not disturb them. These cranes appear to be able to distinguish people in traditional dress and are especially wary of others.

Conservazione

Tendenza della popolazione

stable