The Reef Heron (Egretta sacra) is a NZ native that is widespread in New Zealand but much less common than the more recently arrived White-faced Heron. I have had very little luck getting close enough for a good photo of this species and have probably only come across half a dozen individuals with a camera in hand. So this poor photo is a placeholder for something better.

Reef Heron
Photo taken by Alexei Drummond on 7 October 2017, Omiha, Waiheke island, NZ