The Effect of Cats on Wildlife

The domestic cat is considered an "introduced species" or "invasive species". It is a carnivorous predator. If left to roam or become feral, it can have a negative effect on local species through (a) competition - competing and succeeding in preying on wildlife that is a common prey (b) predation - preying on other species (c) interbreeding - cross breeding with wild cats diluting the wild cat purebred stock - example: Scottish Wildcat (d) disease  - transmitting disease to other wild species of animal. The cat has been accused of the extinction of native species.

Australia is the place where the feral and domestic cat is most commonly attacked in the media for the above reasons. Australians prefer pets other than cats. However despite the continued debate and publicity "the role of feral cats in the decline and extinction of Australian mammalian species remains unclear".(Burbridge & Manly 2002 as referred to in The Welfare of Cats ISBN 978-1-4020-6143-1).

Human activity causing habitat destruction through "over-exploitation of resources, pollution and introduction of exotic species" is the biggest cause of species extinction. The human is the world's most prolific and destructive invasive species. The destruction of rainforest in places such as Borneo and Indonesia are well documented and have an enormously destructive effect on wildlife including rare wild cats such as the clouded leopard and bay cat. This is one of a multitude of examples. "Cats have not been shown to be the primary cause of the loss of native species on mainland continents" (Mead 1982, Mitchell & Beck 1992 and as referred to in The Welfare of Cats).

In the UK the Royal Society for the Protection of Birds (RSPB) says "there is no scientific evidence that predation by cats in gardens is having any impact on bird populations UK-wide" (see RSPB webpage and my comment: Domestic Cats Do Not Decimate Bird Populations and How Feral Cats Affect Wildlife).

Cats are attacked because they are considered an invasive species. They are "targeted for control measures even when there is little evidence to support this" (The Welfare of Cats page 162). An example is blaming cats for the loss of three species of petrel in New Zealand (Little Barrier Island). There was no evidence that the petrels were ever on the island! (ref: Veitch 2001 and Girardet et al 2001). More recently the impact of other species such as ferrets and stoats have been considered in a more balanced appraisal.

There is no doubt in my mind that studies on the impact of cats on wildlife have not been conclusive but have been hijacked by interested parties to promote vested interests. A more balanced approach needs to be taken and more respect afforded to the feral cat.