Whio or Blue Duck

This nationally endangered bird is endemic to New Zealand and lives on fast flowing, forested rivers.  It features on the back of our $10 note.  This pair were on the Kohaihai River, at the beginning of the Heaphy Track.  I was on the swing bridge when I saw them and luckily stopped and took this photo.  When I reached the bank on the other side I looked for them again but they had vanished.