Ducks may be leaving traditional water habitats and looking to dairy farms for food.
Duck shooting season enters its second week today and reports from the first seven days are of patchy shooting.
Some hunters have reported great hauls of game birds, but others say it
has been their worst opening.
George Herman, manager of Whakatane Hunting & Fishing, was one of the unlucky ones, saying his catch last Saturday was the worst in 25 years of shooting.
"Usually we see thousands of ducks," he said. "We only saw 10 per cent of what we normally see, and the birds are getting very, very skinny."
Fish and Game New Zealand said a variety of factors were likely to be responsible for the poor number of ducks in some areas, including a increase in dairy farming and corresponding use of crop silage.
"That seems to be a more attractive food supply," Fish and Game spokesman Ric Cullinane said. "The ducks are thinking 'there's better food over there, I'll go and eat at that dairy farm'."
Drought was also a major factor, with the long, hot summer taking a toll on the duck population and drying up dams and ponds. And clear, calm conditions on opening day had favoured ducks rather than hunters.
"The ducks all quickly disappear and head out to sea," Mr Cullinane said.
"If it's windy, they have to go and find some [inland] water - water where hunters are usually lurking."
But despite the disappointing start for some and the rising cost of ammunition and petrol, duck shooting's popularity is showing no sign of waning.
Forty thousand licences have been issued this season, and about half a million ducks are expected to be killed.
