Visitors to Mount Taranaki are being reminded to leave their pets at home after some Aucklanders took their cats for a walk at the Egmont National Park.
Department of Conservation (DoC) staff recently saw jacket-wearing domestic cats being carried in backpacks by their owners.
DoC senior ranger Dave Rogers said one of his staff did a double-take when they saw the scene.
The Aucklanders' antics have prompted the department to urge visitors to obey the rules, with cats and all other domestic animals forbidden from the park.
They pose a threat to endangered birds, like kiwi and whio, as well as other native species including geckos and insects.
According to DoC, the cats were in the carpark at North Egmont and were being put into the backpacks by their owners when approached by the ranger.
The visitors from Auckland said they weren't aware of the rules and now potentially face an infringement fine; and they're not the first to think that taking their pets up the maunga is a good idea.
Dogs, rabbits, cats and even a parrot have been brought into Egmont National Park by visitors in recent months, DoC said.
"Bringing a pet into the park may seem a harmless thing to do," Rogers said. "But it has potentially deadly consequences for our native wildlife, particularly should the pets run loose or escape from their owners' control."
"Our conservation land is vitally important for the survival of endangered species. Many of our native birds are flightless and have few or no defences against predation. A dog can sniff out and kill a kiwi with ease. Uncontrolled dogs and cats can severely impact our native wildlife.
"Even the most docile and well-controlled pet can instinctively kill," he said.
No pets are permitted in National Parks or dog prohibited areas unless express written approval is granted. Under the National Parks Act owners found with pets in Egmont National Park may be issued an instant infringement fine of up to $800.
Serious or repeat offenders may face prosecution and a fine of up to $100,000 or up to a year in prison. A pet may be seized and impounded if it's found in a National Park or controlled area without a permit.