Will bigger cats lead to bigger prey?

At the 14th Australasian Vertebrate Pest Conference just finished in Darwin, the view from participants was crystal clear - we don't need these "Savannah" hybrid cats in Australia (or New Zealand for that matter).  Not one of the 300 plus delegates had a good word to say to me when they found out that these hybrids may shortly be for sale.

The last paper of the meeting, by Dr. Ricky Spencer from the University of Western Sydney was a fascinating, and disturbing, insight into the growth of wild dog/dingos in eastern Australia.  He presented data that dog/dingos are getting bigger.  He speculated that beyond about 21.5kg, these dogs may switch to larger prey.

What if the same is true of cats?

I had a worried call from Australia (and no doubt the world's) only koala chiropractor, Shane Wassington.  No joke.  He was concerned that if feral cats grow larger, they may become capable of taking on a koala - a species that has never really had to cope with a climbing predator.

We have no idea really whether bigger cats would engage in prey-switching.  But Spencer's paper shows new genes into a population can lead to growth in the population.  Savannah cats are bred to be big.  One of the importing companies says on its website it's "F5s" are more like "F3s" in appearance (ie more like a serval) and once they have the animals in Australia, they'll be breeding for serval appearance - that means big cats doesn't it?

Hmmm - for the sake of a designer cat to indulge fashion sense.