Fish and Game rangers will be out in force this weekend to ensure duck hunters do not jump the gun and break the ban on hunting.
The first Saturday in May is traditionally the opening of the game bird season, but the government decided last week to delay it to support efforts against Covid-19.
Fish and Game chief executive Martin Taylor said the season would now open on the second Saturday following the introduction of alert level 2 - unless that date fell on Queen's Birthday weekend.
This was to avoid a clash with Moving Day on 1 June, when large numbers of farmers shift to new farms.
"Game bird hunting is a national tradition and an important population management tool," he said.
"It's great that all New Zealanders will have an opportunity to hunt ducks, after we move to alert level 2."
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Based on current government projections, opening day was likely to happen mid-May or early June, according to Fish and Game.
For instance, if level 2 was introduced between 11 and 15 May, Opening Day would be 23 May.
If level 2 came into effect between 16 and 29 May, Opening Day would be 6 June.
Meanwhile, Fish and Game rangers will be active throughout the country this weekend to ensure hunters are complying.
Under level 3, hunters other than game bird shooters are able to hunt locally on private land, although overnight trips and motorised vehicles are not allowed and hunters have to stick to their bubble.
Hunters breaking the rules could be fined $4000, face up to six months in prison and risk losing their firearms license.