Feral cats hunting high in Alps and crossing passes

Feral cats have been tracked roaming high into South Island hills and sometimes over the Main Divide.

Manaaki Whenua – Landcare Research field ecologist Ivor Yockney gave an update on the progress of a project to track the movements of 20 feral cats captured and fitted with GPS radio collars in the upper Hope River (Lewis Pass) and Hawdon River (Arthur’s Pass).

The research was started after confirmation that feral cats were killing adult kea at high altitude. Ten cats were trapped in each of the river valleys studied, and the cats were fitted with tracking collars before being released.

Little was known about feral cat habitat use, distribution, density, movement ecology, or impacts on native animal and plant life in these eastern beech forests, Landcare said.

Anecdotal reports of increased feral cat abundance and distribution in those areas would point towards greater threats to native animals from predation.

Yockney said it had been surprising to find feral cats hunting at such high altitudes.

While kea predation was the motivation for the study, the research was about feral cats in the mountain landscape.

Kea were just a sentinel species of presumably a large range of fauna falling victim to feral cats, Yockney said, adding that an adult kea was probably quite formidable prey for a feral cat.

Cats were defined as feral when they are born and bred in the areas where they are found, and had no physical association with humans. It was possible generations of cats had been living in the areas, and at the time the research stared no work had been under way to control the cats in the areas studied, Yockney said.

A ‘‘huge’’ amount of data had been gathered, but analysis had yet to start.

The sole non-tabby cat tracked was a black male in the Hope Valley, from which 336 days of data had been collected.

His home range was 23km long, and he spent much of his time on an area of river flats, but he had also been over the Main Divide to the headwaters of the Tutaekuri River on the West Coast, Yockney said.

There was 245 days of data on another male cat, referred to as the