The Noord Holland provincial authorities are not responsible for cat owners whose cats kill protected wildlife, a court in Haarlem ruled on Wednesday.

The association Huiskat Thuiskat, which advocates keeping cats indoors, had argued that the Noord-Holland local authorities are not exercising their legal duty to safeguard protected species by fining owners who let their cats roam outside.

The judge ruled, however, that “there is insufficient proof that cat owners consciously take the risk that their pet will kill a protected animal”.

Association chairman Roel van Dijk said after the hearing that cat owners should face the same penalty as dog owners who break the law.

“When a dog off the leash kills a fawn, its owner is fined. Cats kill millions of birds and small mammals every year, and nothing happens. The law forbids the killing of protected species and that includes the birds that are being hunted by cats,” he told RTL Nieuws.

Maggie Ruitenberg, of cat expertise centre Kattenkenniscentrum Nederland, who had earlier argued keeping cats indoors is “cruel”, said Van Dijk’s approach to the problem is too “black and white”.

“The figures they quote are often from studies done abroad, for instance in Australia, where there are many stray cats. The situation is not the same as here. And not every domestic cat goes out hunting and not every cat that does catches birds,” she said.

Ruitenberg said her organisation also wants to protect birds by raising awareness among owners. “If you live in an area with lots of birds, then don’t have a cat that likes to go outside, or make sure it can’t get out of the garden,” she said.

Van Dijk said his organisation will appeal against the court decision.