How Cat Breeding Seasons Are Changing Due to Climate Change

AUSTRALIA – When Kristina Vesk first started working at the Cat Protection Society of NSW in 2006, she rarely saw kittens in winter. Now warmer weather means that cats are breeding all year round, increasing the numbers of unwanted kittens and the threat to native wildlife from strays and feral cats.

Animal behaviourist Erica Pankhurst at the Animal Welfare League with cats available for adoption. Photo: Peter Rae

Animal behaviourist Erica Pankhurst at the Animal Welfare League with cats available for adoption. Photo: Peter Rae

Ms Vesk, the society’s chief executive, said there used to be weeks from June to September when the shelter saw a mere few, if any, kittens. But with the climate changing and temperatures rising, it seems cats are increasingly going in heat.

“For the past three years, I don’t think we’ve experienced a full week at any time of year where we don’t have at least a couple of kittens in our care,” Ms Vesk said. “Kitten ‘season’ has grown longer and longer as we keep having … enough warm and sunny days in winter that make cats think it’s a good time to start breeding.”

Vanessa Barrs, a Professor of Feline Medicine at the University of Sydney, said that most cats do not breed in winter to conserve energy and help kittens survive. But breeding can also be influenced by photoperiod, the number of available daylight hours, and “cats artificially exposed to 12 hours of light indoors … can be induced to breed all year round”, she said.

More kittens were surrendered to the Cat Protection Society in the winter of 2013, Australia’s hottest year on record, than ever before in the past, Ms Vesk said.

Last month RSPCA NSW had more than 1110 cats in its care, including a total of 730 kittens. Of the 52,800 cats taken in nationally by the RSPCA in 2015, almost 17,400 could not be rehomed and were put down.

Erica Pankhurst, an animal behaviorist with the Animal Welfare League, said a cat’s biological drive to reproduce kicks in when the weather is warm enough. During kitten season, which usually runs from spring to autumn and is in full force in February, “there’s just kittens coming out of everyone’s ears.”

The shelter is one that has teamed up with Just For Pets, which represents independent pet industry retailer. Together they plan to rehome abandoned animals this weekend, offering pets for adoption in pet shops.

“There’s only a certain number of people going to rescue shelters,” Just For Pets chief executive Karen Justice said. “Making an animal visible so it is seen by pet lovers is the key to rehoming and adoption.”

The RSPCA now recommends early-age desexing of cats, from eight weeks of age, to prevent unwanted litters and that cats be contained on the owner’s property to reduce the impact of hunting.