Critically Endangered
Chatham shag
Leucocarbo onslowi
Chatham shag is a bird in the family Phalacrocoracidae (order Suliformes) — Leucocarbo onslowi, recorded as Critically Endangered.
Appearance
It is a large pied shag with a white throat, breast, belly and patches on the scapulars of the wings, and black or black-brown elsewhere. When breeding the head and hind-neck have a blue metallic sheen, the wings and mantle have a greenish sheen and the rest of the black areas have a purplish-blue sheen. The head has a prominent crest and there are white filoplumes on the neck.
An adult Chatham Islands shag is 63 cm (25 in) in length and weighs around 1,790–2,400 g (63–85 oz).
Range and habitat
The species is endemic to the Chatham Islands, an archipelago around 700 km (430 mi) to the east of New Zealand. In the Chathams it is an inshore species, rarely going more than a few kilometres away from shore, and it is more commonly found in sheltered water such as bays and inlets. It also forages in the large brackish Te Whanga Lagoon.
The Chatham Islands shag, also known as the Chatham shag, is a bird in the cormorant and shag family, Phalacrocoracidae. It is endemic to the Chatham Islands of New Zealand.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
Like all cormorants, the Chatham Islands shag is a pursuit-diver, propelling itself underwater with its feet and returning to the surface to consume small prey caught in its bill. The specific diet of the Chatham Islands shag is poorly known, but is dominated by fish, among them opalfish, flatfish and bullies, as well as cephalopods such as octopuses, squid and cuttlefish.
Little is known about the breeding biology. Males attract a mate with an advertising display in that it stands with its tail cocked up and throws its neck and head back towards its tail, up to 13 times, while making a gargling noise.
In crisis
The species is threatened by introduced predators, disturbance at its breeding colonies and habitat loss. The Chatham Islands shag is threatened by a range of human activities and threats. Colonies on the main islands are also vulnerable to introduced predators such as weka, feral cats and possums.
It is considered critically endangered by the IUCN.
Chatham shag is Critically Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Chatham shag, Wikidata item Q27074620. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
