|An inconsiderate neighbor's cat scared away from my certified backyard habitat...|
Outdoor cats, whether they're pets, feral, or part of a TNR (Trap/Neuter/Release/Return) program, are for the most part harmful to wildlife (and bad for the cats and possibly humans as well). Numerous studies have shown that outdoor cats kill billions of birds, small mammals, and other critters. In fact, the Department of Interior's State of the Birds 2014 Report states that free roaming cats are the number one source of direct, human-caused mortality of birds. While the exact number of animals killed is debatable, that cats are hugely detrimental to wildlife is not. I am unaware of any scientific study that even suggests that outdoor cats actually benefits native wildlife in any way. On the contrary, such groups as the Smithsonian Institution, the US Fish and Wildlife Service, the American Ornithologists' Union, the American Association of Wildlife Veterinarians, the International Association of Fish and Wildlife Agencies, the National Association of State Public Health Veterinarians, the American Society of Mammalogists, and so many others have reached the same conclusion: that outdoor cats have serious negative effects on wildlife populations such as birds.
Domestic cats are not native to this continent and are one of the animals most responsible for extinctions throughout the world. This is particularly true on islands, including isolated patches of habitat that function as islands for the creatures living there (which is what most of our suburban parks are). Even animals that escape the cats' clutches normally do not survive, as cat saliva contains numerous bacteria and viruses that then often infect the cat-bite victim.
Even well-fed cats instinctively hunt for prey, meaning that those in TNR programs or those let out by pet owners continue to kill small animals, whether they wear bells, are declawed, or are well-fed. In fact, by feeding cats what you end up with are subsidized predators that compete unfairly with native predators who starve if they do not capture enough prey. More over, those native predators have even less food because of the cat competition (which are also usually present at predator density levels unknown in nature).
Living outdoors is also not good for the cats either. Feral cats usually live 2-5 years while indoor cats often live over 17 years. Free-roaming cats are exposed to predation, cold, heat, accidents and illness. Such diseases as rabies, distemper, feline leukemia, roundworms, bartonellosis, typhus, and toxoplasmosis can not only establish themselves in cats, but then can spread to wildlife and perhaps even humans. Indeed, cats are the main host or reservoirs for some of these such as toxoplasmosis, and cats are the primary route of infection of this to other creatures such as deer and bobcats.
It is for these reasons and many more that numerous environmental organizations are against outdoor cats, including the National Audubon Society, the Wildlife Society, the National Wildlife Federation, the American Bird Conservancy, and even PETA.
I often hear that it is not the animals fault, but rather humans who are responsible for the present situations, and yes that is true. But it also only man that can try and fix these problems, even if they involve tough decisions and actions. It is our responsibility to do so rather than allow things to get worse or condone our mistakes.
I do not know even one professional naturalist or natural resources manager that believes that outdoor cats are something that benefit wildlife, indeed just the opposite. Just because cats are charismatic does not mean that we should value their lives over that of native wildlife or give them special treatment. We do not allow dogs or other pets to run wild, form colonies, or defecate and trespass onto neighbors yards. So why do we treat cats differently, and at the expense of other deserving wildlife? We should not tolerate any non-native predator affecting our native wildlife, let alone subsidize them by feeding or forming colonies for them. Cats do not belong in nature and should be removed rather than encouraged. There's nothing wrong with cats, as long as they're indoor pets. So we need to make sure that people keep their cats neutered and safe indoors; safe for the cats and for wildlife.