Climate change raises cat threat

Photo / Supplied

Warmer temperatures would move feral feline colonies into conservation hotspots, researcher finds.

Vulnerable native species may face further risk as climate change makes more of our country hospitable to stray cats, a researcher says.

In a new study in the journal Applied Geography, Unitec natural sciences lecturer Dr Glenn Aguilar used species distribution modelling to describe areas highly favourable to stray cats, and then investigated what effects a warmer climate would have.

Under one grim 2070 model, climate change could widen the range of areas suitable for feral cats, bringing them closer to conservation hotspots in new places like the central North Island, and the top and central areas of the South Island.

Dr Aguilar's previous work has demonstrated links between human population density, economic deprivation and the occurrence of stray cats, showing that a dense population generally indicated stray cats would be present.

In Auckland, an analysis of two decades of records found how South Auckland, Glen Innes, the central city and pockets of West Auckland had the highest populations of stray cats, with spikes in December and March coinciding with breeding patterns.

"I had the idea that we could take all this cat distribution data from Auckland and try to expand it throughout New Zealand and see whether there's an effect when you have a climate change scenario for modelling."

Using the latest greenhouse gas trajectories set out in the UN-adopted Relative Concentration Pathways data and a series of GIS maps, he was able to show an increase in the areas suitable for at-large cats.

Peter Dormon, founder of the Lonely Miaow Association, an Auckland-based organisation focused on rescuing and caring for stray cats, saw the research as a "valuable contribution" for those in animal welfare.

"Cats can survive in very cold climates, such as the Auckland Islands and Kerguelen, but do thrive in warmer climes.

"The dispersal of stray cats today into rural and semi-urban areas is definitely a threat to the native wildlife in nearby areas of high conservation values," Mr Dormon said.

Dr Aguilar hoped his research would help how we plan for limiting the effects of such an eventuality.

"The modelling could provide some guidance in strategy and policy making - it's an interesting exercise when trying to build an idea of how climate change can effect some species, not only stray cats."

Responding to the study, cat control campaigner Gareth Morgan said the rates of extinction of our endemic species that were cat prey were already at unprecedented levels, "and on that issue at least the relevance of the authors' contribution is limited".

"However, their work does suggest that with climate change the scope for even greater destruction of New Zealand's endemic species by cats will increase above what we already are accommodating through management negligence."

The cat conundrum

•Globally, cats living in a wild or feral state are held responsible for at least 14 per cent of extinctions of birds, mammals and reptiles.

•A New Zealand Veterinary Association-commissioned review this year called for urgent measures to control roaming cats, including compulsory microchipping and registration, a restriction on ownership in "environmentally valuable areas" and keeping cats indoors. The review was criticised by Auckland SPCA executive director Bob Kerridge.

•The Morgan Foundation has blamed cats for causing harm to 33 endangered native bird species and the extinction of nine. It has controversially called for pet cats to be fitted with bells, kept inside at all times and not replaced after they die, and for homeless cats to be either homed or eradicated.