There is a colony of Pied Shags just upstream of the footbridge but one day I thought I saw an all-black shag fly past me. This was recently confirmed by Marion Cherry, who kindly sent the photo above of two Kawau Tūī, Little black shags:
Length: 61 cm; Weight: 800 g
Similar species: Little shag, Black shag
A medium-sized shag of coastal and inland waters with all-black plumage, dark facial skin, a thin black bill and black feet. The distinctive iris is much brighter green eye than other shag species.