Whio - NZ's Blue duck.
I first saw and heard this duck on a trip to the Whirinaki back country. I had been told that it was rare to see or hear these ducks. I was sitting beside the river after a days tramping - soaking my feet in the freezing water. Suddenly 2 ducks flew up the river with a rushing of wings. They didn't land but I thought myself lucky to have seen them albeit in a flash.
The next day following the river I heard a whistle - sounding like the whistle on a life jacket - Yes this was the Whio I was told.
Watching the river banks carefully it still was very hard to see these birds. I first saw their light coloured beaks and then was able to distinguish them from the riverbank foliage. Over the next 2 days I was lucky enough to see 4 pairs on the river.