The Stewart Island shag is a species of shag found on New Zealand's South Island and Stewart Island. The Stewart Island shag has sometimes been split into two species, the Foveaux shag and the Otago shag.
Region
Southern New Zealand
Typical Environment
Occurs along the southeast coast of the South Island and around Stewart Island/Rakiura, especially near rocky coasts, headlands, and offshore islets. It forages in inshore marine waters over kelp beds and rocky reefs, rarely far from land. Breeding colonies are located on cliffs, stacks, and low rocky islands with ledges for nesting. Roosting sites are reused for many years and accumulate conspicuous guano deposits.
Altitude Range
Sea level to 200 m
Climate Zone
Temperate
Ease of Keeping
Beginner friendly: 1/5
A large blue-eyed shag of southern New Zealand, it shows striking plumage dimorphism: some birds are pied with clean white underparts, others are wholly dark bronze-brown. The taxon has often been split into two species, the Foveaux Shag (Leucocarbo stewarti) around Foveaux Strait and Stewart Island, and the Otago Shag (Leucocarbo chalconotus) along the Otago coast. Colonies are highly sensitive to disturbance at breeding sites, where birds nest in dense groups on rocky islets and headlands.
An 1845 lithograph by Charles Hullmandel of the bronze phase
An Otago shag in Otago
Temperament
social and colonial
Flight Pattern
strong direct flight low over water with rapid wingbeats
Social Behavior
Breeds in dense colonies on rocky islets and coastal cliffs, often returning to the same ledges year after year. Pairs are seasonally monogamous, building nests of seaweed and vegetation cemented with guano. Typical clutches are 2–3 eggs, with both adults sharing incubation and chick-rearing duties.
Migratory Pattern
Resident
Song Description
Generally quiet at sea but becomes vocal within colonies. Emits low grunts, croaks, and hisses during courtship, nest defense, and when interacting at roosts.
Plumage
Dimorphic: a pied morph with glossy black upperparts and white underparts, and a bronze morph that is uniformly dark brown-bronze with a slight greenish sheen. Feathers are sleek and tightly set, giving a streamlined look. Breeding birds show fine white filigree on the head and neck.
Diet
Primarily takes small to medium demersal fish, along with cephalopods and crustaceans captured by pursuit diving. It uses powerful feet and partially spread wings to propel itself underwater. Foraging is usually solitary or in loose groups near reefs and kelp beds, with dives commonly reaching the seabed in shallow coastal zones.
Preferred Environment
Forages in clear, inshore marine waters over rocky reefs, kelp forests, and sandy patches adjacent to reefs. Often feeds within a few kilometers of breeding and roosting sites.
