红胸黑雁种

保育状况

其被列为《濒危野生动植物种国际贸易公约》附录二的物种，被限制出口及贸易。

中国国家重点保护动物等级：二级

The red-breasted goose (Branta ruficollis) is a brightly marked species of goose in the genus Branta from Eurasia. It is currently classified as vulnerable by the IUCN.

Taxonomy and etymology

The red-breasted goose is sometimes placed in its own genus Rufibrenta but appears close enough to the brant goose (Branta bernicla) to make this unnecessary, despite its distinct appearance. Today all major authorities include the red-breasted goose in Branta. Genetic studies indicate that the red-breasted goose may be one the few known examples of hybrid speciation in birds, being the result of ancient interbreeding between the ancestral brant goose and white-cheeked goose (the latter being the ancestral species that later split into all today's Branta species, except the brant and red-breasted geese). This interbreeding appears to have happened at least 3.5 million years ago, with the lineage of the red-breasted goose following its own evolutionary path since then.

Branta is a Latinised form of Old Norse Brandgás, "burnt (black) goose and ruficollis is from the Latin rufus "red" and collis "necked".

Description

All the species of the genus Branta are distinguished by their dark sooty colour, relieved by white, and as a distinction from the grey geese of the genus Anser. This bird measures 53–56 cm (21–22 in) in length, 1.16–1.35 m (3.8–4.4 ft) in wingspan. It is sexually dimorphic, with males being slightly heavier than females, weighing 1.2–1.62 kg (2.6–3.6 lb) and 1.05–1.13 kg (2.3–2.5 lb), respectively. This brightly marked species is unmistakable, but can be surprisingly difficult to find amongst brant geese. At long distances, the red of the breast tends to look dark.

Distribution

The red-breasted goose breeds in Arctic Siberia, mainly on the Taymyr Peninsula, with smaller populations in the Gyda and Yamal peninsulas. Most winter along the northwestern shores of the Black Sea in Bulgaria, Romania and Ukraine (occasionally moving further southwest to Greece), but some winter in Azerbaijan. It is a rare vagrant to Ireland and other western European areas, where it is sometimes found with flocks of Brent or barnacle geese. However, since it is common in captive wildfowl collections, escapees outside its usual range are fairly frequent.

A large part of the population traditionally wintered in Kirov Bay in the Caspian Sea, but in the 1960s the area became unsuitable for the geese due to the agricultural change. Vineyards and cotton replaced the cereal crops used by the wintering geese.

Behaviour

Calls of red-breasted goose are include honking and hissing in aggression.

The red-breasted goose often nests close to nests of birds of prey, such as snowy owls, peregrine falcons and rough-legged buzzards, which helps to protect this small goose from mammalian predators such as the Arctic fox. The closer the goose's nest to the eyrie (bird of prey nest), the safer it is from predation. Based on the size and how timid the geese are, they rely on the bird of prey for defense. It is extremely unusual for the bird of prey to attack, but is still possible. Additionally, the larger the colony the safer it is. This in turn positively influences the survival and reproductive success of the red-breasted goose. Aside from nesting close to birds of prey, red-breasted geese nest on islands on rivers which also protects them from land-based predators.

Conservation

In autumn of 1997 the population was estimated to be around 88,000 individuals. In the winter these numbers can shrink to around 70,000. The red-breasted goose is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies. The red-breasted goose is legally protected in many states, however hunting is still continued. The AEWA is monitoring the species and providing up to date information on the status of the species, its habitat, migrations, ecology, and conservation needs. It was considered a Vulnerable species by the IUCN. Over 80% of the population roost during the winter at just five sites, with nearby feeding areas threatened by changes in land use. In addition, there has been a strong decline in numbers in the last decades. However, it is possible that this decline may have been exaggerated, as it is possible that some birds may winter at unknown sites.