Stewart Island Shag
A species of Cormorant, Also known as Bronze Shag Scientific name : Leucocarbo chalconotus Genus : Cormorant
Stewart Island Shag, A species of Cormorant
Also known as:
Bronze Shag
Botanical name: Leucocarbo chalconotus
Genus: Cormorant
Content
Description General Info
Photo By Lars Petersson
Description
The species is dimorphic, with two plumages. Roughly one quarter of the individuals are pied, with dark and white feathers, and the rest, known as bronze shags, are dark all over. Both morphs breed together. These large, chunky birds are about 70 cm long, weigh about 2–3 kg, and are slightly larger than Foveaux shags. They can be distinguished from Foveaux shags by their facial ornamentation in the breeding season: Foveaux shags have dark orange papillae on their face, whereas Otago shags have both papillae and small bright orange facial caruncles above the base of the bill.
Size
71 cm
Feeding Habits
Stewart Island Shag principally consumes fish, accounting for 70% of its diet, including various species like Tripterygion. It also eats crustaceans, cephalopods, and polychaetes, favoring invertebrates in winter. Stewart Island Shag employs pursuit-diving to forage, occasionally forming small groups for feeding.
Habitat
Stewart Island Shag typically inhabits coastal marine environments, favoring sheltered waters such as bays and inlets for foraging. Its breeding and roosting sites are often situated on rocky coastlines and small offshore islands or stacks, offering a proximal relationship with nearshore waters.
Dite type
Piscivorous
General Info
Distribution Area
Archaeological evidence shows that Otago shags were formerly found along the entire east coast of the South Island up to Marlborough, but when humans arrived the population was devastated, reduced by 99 percent within 100 years with a corresponding loss of genetic diversity. It became restricted to the rocky offshore islets off the Otago Peninsula, and has scarcely recovered since that time. There are less than 2500 Otago shags remaining, but they can be seen at Otago Harbour, as far north as Oamaru, and as far south as the Catlins. Restricted to a small area, and having little or no genetic variation, they require conservation efforts tailored to these extinction risk factors; this could include reintroduction to part of their former range. Otago shags breed colonially from May to September, making raised cup nests out of organic material and guano on islands and sea cliffs. Colonies are large enough to be strikingly visible, and are used year after year. One notable colony is on the northern shore of Taiaroa Head, at the mouth of the Otago Harbour. They feed in coastal waters less than 30 m deep and are rarely if ever seen inland or far out to sea.
Photo By Lars Petersson
Scientific Classification
Phylum
Chordates Class
Birds Order
Gannets and Relatives Family
Cormorants Genus
Cormorant Species
Stewart Island Shag