There are some 36 species of shag worldwide. Twelve of these are found in New Zealand, of which eight are endemic (found nowhere else). In many countries, shags are called cormorants. The name shag is thought to refer to the shaggy crest some species have on their heads. Four species of shag are found at ZEALANDIA: the kawau pū (black shag), kāruhiruhi (pied shag), kawau tūī (little black shag) and kawau paka (little shag). These four species all belong to the genus Phalacrocorax, the black footed shags, which are found mainly in freshwater or coastal seawater.
Shags are swift underwater swimmers, with a sharp hooked beak to help them catch fish and small crustaceans. After a bout of fishing, shags must spend a lot of time perched with their wings spread out, preening and drying their feathers. This is because their feathers are not waterproof, making it easier for them to dive and stay underwater, but it also means the birds quickly get waterlogged and cold and must dry off afterwards.
The little black shag is small and black with a greenish gloss. Their dark edged feathers give a scalloped effect on the back. They have a long, slender, grey bill, dark facial skin and green eyes. Juveniles are similar but more brownish. They can sometime be confused with black-phased and juvenile little shags, but can be distinguished by differences in bill and tail length. Little shags have short, stubby, yellow bills, yellow facial skin and a noticeably longer tail than the little black shag.
These shags are also found in Australia, and are believed to have arrived relatively recently to New Zealand. First reported in 1840, their distribution has spread through the North Island and to parts of the South Island.
The little black shag is the only shag species that doesn’t yet breed at ZEALANDIA, so few roost here between November and March when they are breeding elsewhere. However, up to 60 have been observed roosting here in winter, the highest numbers usually in August/September.