Grey Crowned Crane

The grey crowned crane is closely related to the black crowned crane, and the two species have sometimes been treated as the same species. The two are separable on the basis of genetic evidence, calls, plumage and bare parts, and all authorities treat them as different species today. There are two subspecies. The East African B. r. gibbericeps (crested crane) occurs in the east of the Democratic Republic of the Congo and in Uganda, of which it is the national bird represented in its national flag, and Kenya to eastern South Africa. It has a larger area of bare red facial skin above the white patch than the smaller nominate species, B. r. regulorum (South African crowned crane), which breeds from Angola south to South Africa. The grey crowned crane is about 1 m (3.3 ft) tall, weighs 3.5 kg (7.7 lbs), and has a wingspan of 2 m (6.5 ft). Its body plumage is mainly grey. The wings are predominantly white, but contain feathers with a range of colours, with a distinctive black patch at the very top. The head has a crown of stiff golden feathers. The sides of the face are white, and there is a bright red inflatable throat pouch. The bill is relatively short and grey, and the legs are black. They have long legs for wading through the grasses. The feet are large, yet slender, adapted for balance rather than defence or grasping. The sexes are similar, although males tend to be slightly larger. Young birds are greyer than adults, with a feathered buff face.

This species and the black-crowned crane are the only cranes that can roost in trees, because of a long hind toe that can grasp branches. This trait is assumed to be an ancestral trait among the cranes, which has been lost in the other subfamily. Crowned cranes also lack a coiled trachea and have loose plumage compared to the other cranes. The grey crowned crane has a breeding display involving dancing, bowing, and jumping. It has a booming call which involves inflation of the red gular sac. It also makes a honking sound quite different from the trumpeting of other crane species. Both sexes dance, and immature birds join the adults. Dancing is an integral part of courtship, but also may be done at any time of the year.
Flocks of 30–150 birds are not uncommon.

Although the grey crowned crane remains common over some of its range, it faces threats to its habitat due to drainage, overgrazing, and pesticide pollution. Their global population is estimated to be between 58,000 and 77,000 individuals. In 2012 it was uplisted from vulnerable to endangered by the IUCN.

Source:Wikipedia

Publicado por joshua_sam joshua_sam, 06 de junio de 2020

Observaciones

Fotos / Sonidos

Qué

Grulla de Corona Gris Balearica regulorum

Observ.

joshua_sam

Fecha

Abril 10, 2019 03:00 PM IST

Lugar

Narok, KE (Google, OSM)

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