The King Shag (Leucocarbo carunculatus) is endemic to New Zealand and only occurs in the Marlborough Sounds and is considered a nationally endangered species with a population numbering fewer than 900 individuals.
The King Shag is also known by a number of other names, kawau, te kawau a toru, kawau pāteketeke, New Zealand king cormorant, rough-faced shag, carunculated shag, Marlborough Sounds shag, Cook Strait cormorant.
A tale from He Korero Pūrākau Mo Ngā Taunahanahatanga a Ngā Tūpuna (Place Names Of The Ancestors) – A Māori Oral History Atlas tells of Kupe travelling with his pet birds. The most loyal of these was a giant shag, Te Kawau a Toru, which discovered Te Aumiti (French Pass) which runs with great violence between Rangitoto (D’Urville Island) and the mainland. Te Kawau A Toru was overcome by the strong currents when testing the pass for Kupe and perished there. The body of the great bird forms the reef which lies in the Pass.
The King Shag is about 76 cm long and 2.5 kg in weight. They are black and white with big pink feet. The black feathers on forehead, crown and nape extend to just under the bill, making King Shags appear ‘dark-headed’ compared to the similar-sized pied shag. The dorsal area of mantle, scapulars, back and tail are black apart from adults, which have a white patch or stripe near the leading edge of the inner wing.
Breeding adults have a patch of sulphur-yellow warty ‘caruncles’ on each side of the upper bill base; the size and colour intensity of these is reduced at other times of the year. The cobalt blue eye-ring (not part of the eye) is shared with other pink-footed ‘subantarctic’ shags, providing this group with the generic, but technically incorrect name “blue-eyed shags”. Juvenile birds differ from the adults in having dull brown upper parts (rather than black) and pale facial skin.
King Shag breed on low rock plateaus, steep rock faces or rock ridges between 2 and 33 m above sea level, with 80% of the population breeding lower than 14 m above sea-level and occurs during winter. Nests are platforms of sticks and seaweed, cemented with guano. The 1-3 pale blue eggs are usually laid in May-June. There is no information on incubation length or nestling period, but juveniles are present at colonies from July onwards. Adults (likely females) feeding chicks depart colonies at sunrise, arriving back at the colony about midday. A second departure happens short after midday (likely males).
The King Shag feed up to 25 km in a predominantly southwest direction from the main colonies, mainly in waters up to 50 m deep. All the preferred prey items are bottom-dwelling species, highlighting the King Shag deep diving abilities and dependence on a healthy benthic environment in the deeper waters of the Marlborough Sounds.