The country’s highest administrative court has given the provincial authorities in Overijssel six months to prove it is necessary to shoot geese in protected nature reserves, after finding the province does need a permit to cull the birds after all.

The case was brought by bird protection group Vogelbescherming.

The Council of State first ordered the province to carry out more research into the goose culls in December 2015 so that a proper permit could be granted. Nevertheless, the province decided no permit was necessary and pressed ahead with shooting hundreds of geese instead.

In Wednesday’s judgment, the council said that the provincial authority had not been able to prove that it did not need a permit to shoot geese and it must now carry out the necessary research within six months. Overijssel will also have to pay all Vogelbecherming’s legal costs, local broadcaster RTV Oost said.

The Dutch government wants to reduce the size of the goose population in the Netherlands back to its 2005 levels which, experts say, will entail the slaughter of 500,000 birds.

Farmers in the Netherlands were paid €16.3m for damage to crops and farmland caused by wild animals in the first six months of last year, most of which was due to geese.