Australian pied cormorant

The Australian pied cormorant (Phalacrocorax varius), also known as the pied cormorant, pied shag, or great pied cormorant, is a medium-sized member of the cormorant family. It is found around the coasts of Australasia. In New Zealand, it is usually known either as the pied shag or by its Māori name of . Older sources may refer to it as the "yellow-faced cormorant".

Taxonomy

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.

Two subspecies are recognised: It stands between tall, with a wingspan of . 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.

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).

Distribution and habitat

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.

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 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).

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. Birds in colonies can often be observed entangled in recreational fishing line with hooks embedded in the body.

[[File:Distribution and trends.jpg|center|frameless|880x880px|Distribution of pied cormorant in Australia and New Zealand It will dive both in shallow, still water and in rapidly moving currents. Typical dive times are around 40 seconds, with a recovery period of 10–15 seconds between dives although this is dependent on depth. Risk of predation by sharks and the abundance of food comprise a trade-off where the pied cormorant may choose to hunt in deeper waters where prey is less abundant if the risk is too high during warmer months when sharks are present more often.

Breeding

thumb|With nesting material

The pied cormorant preferably breeds in small (<30 pairs) sheltered colonies (harbours, estuaries and lakes) with rarer occurrences on exposed coasts or islands, Courtship behaviour is initiated by the male in close proximity to a future nest site. Wing waving by the male is conducted in silence while gargling can be a form of female recognition. The males can also hop up to 1 m in the air with both feet to attract female attention.

Nests are typically large platforms formed of sticks and foliage cemented with droppings averaging in diameter on the ground or in trees. Males collect most of the nest material, while both sexes share construction tasks.

Gallery

File:Australian pied cormorant (Phalacrocorax varius hypoleucos) in flight Blanchetown.jpg|Murray River, South Australia

File:Pied Cormorant RWD1.jpg|Auckland, New Zealand

File:Pied Cormorants.jpg|Pair in Abel Tasman National Park, New Zealand

File:Immature and adult pied shags (Phalacrocorax varius).jpg|Immature and adult, New Zealand

File:Pied Cormorant on a beach in Australia.jpg|Pied cormorant resting on sand

File:Pied Shag . (8064361718).jpg|Pied shag drying wings

File:AustralianPiedCormorantAtSydneyOperaHouse2012.jpg|Pied cormorant in an urban setting – the Sydney Opera House

File:Pied Shag Fishermans Point.jpg|On water at Fishermans Point, Lake Ellesmere.

File:Phalacrocorax varius 2026 02.jpg|At Zealandia Wildlife Sanctuary, New Zealand

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References