White-Faced Heron (Ardea novaehollandiae)
Although not common in NZ until the mid-twentieth century, the white-faced heron is now the most common NZ heron. In the estuary it can be seen on the mudflats wading through the water in search of food or roosting up on the edge of the mudflats.
The white-faced heron is blue-grey in colour, with a distinctive white face and throat. Being a heron it has a long neck and long legs. Its legs are yellow in the non-breeding season but turn pinkish when it's breeding. The iris is also yellow. The long, sharp bill is black. When feeding it wades through the shallows at the water's edge and stops every few metres to stir up the mud with its foot, presumably to cause prey to move.