Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Stercorariidae
Genus: Stercorarius
Species: S. antarcticus
Binomial name: Stercorarius antarcticus
Synonyms: Catharacta antarctica, Catharacta skua lonnbergi, Stercorarius antarcticus, Lestris catarractes, Lestris antarcticus, Stercorarius antarcticus, Megalestris antarcticus,
Common names: Brown skua, Southern skua, Southern great skua, Antarctic skua, Subantarctic skua, or hākoakoa (Māori),

Stercorarius antarcticus is a large, stocky (64 cm length, 2 kg weight) marine bird. It is a top avian predator in the subantarctic and other southern New Zealand islands.
It is dark brown plumage overall, sometimes uniformly dark brown or paler brown with pale creamy flecking. There is a distinctive white outer wing patch at the base of primary flight feathers. Its eyes are a dark brown and the webbed feet are black. This species is highly predatory and it has a large, stout, hooked bill that is used to rip open fish, other seabirds (eg. penguins), small mammals, eggs and carrion.
Stercorarius antarcticus breed on Stewart Island and the Chatham, Snares, Antipodes, Auckland and Campbell islands. Two eggs are laid during September to December, and the young are fed for 4–5 months. The New Zealand population is fewer than 2,000.

A Skua (Stercorarius antarcticus) at the Snares, Subantarctic Islands.
Photo by Tamzin Henderson @ www.tamzinnz.com
Skua by Tamzin S Henderson.jpg

Photos below are of a Brown skua taken by Malcolm Francis off Tutukaka, Northland.Sula Leucogaster by Mal Francis.jpg

Sula Leucogaster by Mal Francis-002.jpg 

Thanks to Wikipedia for text and information     https://creativecommons.org/licenses/by-sa/3.0/