Mr Darby championed the hoiho for about 20 years in the 1970s and ’80s, researching hoiho feeding strategies and patterns.
He did his conservation and monitoring work in his spare time while working as assistant director of Otago Museum in Dunedin, a role he earned in 1971.
After retiring to Wānaka in the 1990s, he began monitoring the rare grebes and built them a nesting sanctuary at the Wanaka Marina.
"I am chuffed," Mr Darby said.
"They are the two species of birds I’ve really worked on. But I had nothing to do with it," he hastened to add.
He was delighted Thura Otago Museum had got on board to champion the hoiho and bring attention to its environmental troubles.
"When I first started, every dead and dying penguin was referred to me and my kid grew up with penguins in the bath," he said.
He hoped by winning the Bird of the Year award, there would be more communication about the private hoiho and the type of conservation work needed to protect them in the wild.
Asked if he had a third bird he championed that could come to national attention next year, Mr Darby, who is now 88 years old, laughed.
"No! The big thing is having the time to do the work," he said.
The top 10 birds announced on Monday are:
- Hoiho yellow-eyed penguin (6328)
- Karure Chatham Island black robin (5442)
- Kākāpō (4548)
- Ruru morepork (4467)
- Kea (4,206)
- Pīwakawaka fantail (4205)
- Takahē (3892)
- Tawaki piki toka eastern rockhopper penguin (3834)
- Kōkako (3445)
- Toroa Antipodean albatross (3415)