The Arctic Skua migrates to New Zealand coastal waters during November to April and is the most numerous skua, seen often either settled on the water or harrying White-fronted Terns or Red-billed Gulls forcing them to disgorge fish which are then caught and eaten in mid air.

This bird is dimorphic, occurring in dark (about 80% in NZ) or light mottled plumage phases.  All adults have a black bill, legs and feet and a dark underwing with a single pale patch at the base of the primaries. Upperparts are dark except for 3 – 4 pale shafts at the base of the primaries.  The dark phase can have white flecks on the rump and the pale phase has a less distinct cap, streaked undertail and pale flecks on the rump and uppertail.  When in New Zealand the bird is usually silent.

Breeding occurs in the Arctic and Subarctic where they usually lay 2 brown eggs in a shallow scrape or cup of vegetation.

References: Heather, B.D.; Robertson, H.A. 2000 The Field Guide to the Birds of New Zealand. Auckland, Viking.
Moon, G The Reed Field Guide to New Zealand Birds.