Mother's Day has spurred the SPCA to appeal to the human maternal instinct to find temporary mums for kittens.
Kitten season - the time of year when most kittens are born - begins in October, and the SPCA needs temporary homes for them until permanent homes are found.
"Mother's Day is drawing attention to the fact we have some beautiful animals for adoption," said SPCA executive director Bob Kerridge.
"I think we've got 200 kittens in foster care at any one point, and another 100 kittens waiting for recovery or adoption."
SPCA subsidises spaying and food for kittens while they are temporarily adopted.
"Every year, all SPCAs receive a huge number of kittens in a season. We have foster parents - temporary mothers - that look after them until ready for adoption."
"If we didn't have temporary mums, we wouldn't be able to handle the numbers we get," Mr Kerridge said.
Cats can have three litters during kitten season. Each gestation period lasts around 65 days.
"Three litters could represent 20-30 kittens so it's important that people do de-sex animals," Mr Kerridge said.
"We always need foster homes. We assist with cat food and veterinary problems. We cover all possible expenses, but we do find that a lot of families take care of food themselves and we're very grateful."
Two-legged mums are also needed to take care of the four-legged variety, Kerridge added.
"We get mothers surrendered because they dared to have kittens. We're always pleading for mother cats to find happy homes.
"Surveys we've done indicate that over 90 per cent of people feel that if they have an animal in the family, the animal is one of the family."