When does inter-cat communication become inter-cat aggression?

The PDSA's most recent Animal Wellbeing Report surveyed 12 334 cat owners and 1699 of their veterinary surgeons. It found that 25% of the UK population has a cat — an estimated 11.1 million cats (PDSA, 2015). Many of these cats are living in multi-cat households, despite 1.7 million owners recognising that their cats ‘aren't keen on each other’. The report also found that within these households a substantial proportion of the cats are forced to share their resources with other cats, with 50% sharing litter trays and 58% sharing water and food bowls.

Yet companion and feral cats have evolved from a species (Felis silvestris lybrica — the African/Arabian wildcat) that only about 12 000 years ago was still to embark on the domestication process (Serpell, 2000). These ‘wildcats’ were solitary hunters; they had to be, as prey was scarce and competition from another cat within an individual's territory immediately reduced a cat's capacity to perform that most basic of functions — to thrive and survive (Fitzgerald and Turner, 2000). Each cat, as do present day feral cats, required 12 to 15 rodents per day to survive. To successfully kill 12 rodents, with an approximately 10% success rate, a cat needed access to a minimum of 120 opportunities to hunt. As this precarious existence was occurring in harsh conditions, another cat attempting to share the resources provided by the environment would not enhance either cat's chances of survival (Bradshaw et al, 2012).