Pied Cormorant

识别特征

The pied cormorant is predominantly black on its back and upper surface of the wings and white on the underside with males weighing approximately 2.2 kg and females 1.7 kg. It stands between 65–85 cm tall, with a wingspan of 110–130 cm. A small yellow patch between the bill and the eye on each side of the head is likely to have been the reason for the historical common name. It has large webbed feet which it utilises to pursue fish underwater, steering with half opened wings. The bird has a large hooked bill, green eyes with a blue eye ring and black legs and feet. The eyes have a special nictitating membrane for underwater protection. The pied cormorant can often be seen spreading its wings after diving to help dry the feathers, as it has inadequate waterproofing. This lack of feather waterproofing may help the cormorant spend longer underwater due to decreased buoyancy effects.<p>The two subspecies have slight differences in physical characteristics. Similar species include the black-faced cormorant (slightly smaller) and the little pied cormorant (substantially smaller).

分类信息

The Australian pied cormorant was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it in the genus Pelecanus and coined the binomial name Pelecanus varius. Gmelin based his description on the "pied shag" from Queen Charlotte Sound, New Zealand, that had been described in 1785 by English ornithologist John Latham in his book A General Synopsis of Birds. Latham had based his own description on a specimen in the Leverian Museum and on a watercolour by Georg Forster that belonged to Joseph Banks. Forster had accompanied James Cook on his second voyage to the Pacific Ocean. The Australian pied cormorant is now one of 12 species placed in the genus Phalacrocorax that was introduced in 1760 by the French zoologist Mathurin Jacques Brisson.<p>Two subspecies are recognised:

学名

Phalacrocorax varius

命名信息

(Gmelin, JF, 1789)

目

Suliformes

科

Phalacrocoracidae

属

Phalacrocorax

分布与栖息地

The pied cormorant is listed of least concern in the IUCN red list of threatened species, reflecting its large range with a relatively stable population.<p>In New Zealand its range on the east coast extends as far south as Christchurch, though this is a recent extension—older books report it no further south than Kaikōura. The range extensions have accompanied population recovery from heavy persecution in the early 1900s and likely represents recolonization of the former range. The pied cormorant is listed as Nationally Vulnerable in New Zealand. The population has been growing from around 700 breeding pairs in the 1950s to an estimated 3,000 pairs post 2000 (Refer to population trend data).<p>In Australia it is only moderately common in the eastern states (both the coast and inland wetlands), but abundant in the south-west, particularly along the coast. Its federal conservation status is 'secure' and only changes to 'near threatened' in Victoria. It can be found in all states except Tasmania. The pied cormorant has been calculated to be at high-moderate risk from fishing – particularly from set and inshore drift nets. Birds in colonies can often be observed entangled in recreational fishing line with hooks embedded in the body. In the past, the pied cormorant was seen as competition for commercial fishing and sometimes shot.<p>Although typically found in marine habitat—sometimes solitary, sometimes in pairs, sometimes in vast flocks of hundreds or thousands—it is also attracted to inland waters, including lakes, deep and open wetlands, and rivers. In Australia, the birds can often be found at inland waterways while in New Zealand it prefers coastal areas close to its prey. Adult birds are sedentary and can often be seen roosting in trees, on rocks or logs in the water. The birds seem unaffected by variable salinity, turbidity and shoreline vegetation provided there are available perches.

迁徙

Resident species

行为

Migration pattern: Resident species.

保护状况

种群趋势

unknown