Keep Your Cats In-Doors

I was feeling like getting some negative email so I thought I would mention a topic that gets some people a little catty: house cats as predators. It's kind of like the issue where some people think we need more assault weapons on the streets. But first, let me be clear, bad as the problem is, habitat loss is the number one factor driving down wildlife populations of all types and species. Cats are an important secondary issue, however, and there is a very simple solution that everyone can do: keep your cat in your house where it belongs.

Cats represent a super predator with a major impact. Hunting is instinctual and something they do even if well fed. Unlike wild predators, they have a steady source of food that they don't have to work to obtain. Because of that food resource, the fact that many people have multiple pets and cat ownership is widespread, the density of cat predators becomes much higher than the formerly natural environment where the predators are held in check by availability of prey. Also, many wild predators are constantly dealing with illness, injuries or parasites for which most domestic cats immediately receive care. All of these factors make domestic cats a much more effective predator.

The US Census Bureau found 60 million domestic cats nationwide in 1990. It's estimated that there are another 40 million feral cats. In a study in Wisconsin by John Coleman and Stanley Temple, they found that "small mammals like mice and voles make up about 70 percent of their (rural cats) diets, birds constitute about 20 percent of their kills and a mix of other animals constitute the remaining 10 percent." They contacted rural cat owners and followed 656 cats over an 18-month period. Just one cat racked up 1690 kills (all animals) during that time. The number of animals killed per cat in the study varied so they also looked at many other research projects. Their look at other research showed: "On an annual basis, studies record low estimates of 14 animals per free-ranging urban cat to at least one animal per day for rural cats. Other studies reported 28 kills per year for urban cats and 91 kills per year for rural cats." In the end their work estimated that rural cats, alone, in just the state of Wisconsin, were killing as many as 219 million birds per year. That was their high range, but think about it multiplied by 50 states. See to read an article they wrote on their findings.

This problem hits islands really hard. Cats and other introduced predators have devastated many seabird colonies in Hawaii and other Pacific islands. In New Zealand, cats are considered the primary cause in the extinction of eight bird species and the eradication from those islands (but not from the world) of forty others. On Vashon, cats are probably right after habitat loss or co-equal to it in the extermination of our native Blue Grouse and introduced species such as Gray Partridge (used to be known as "Huns") and Bobwhite. California Quail are still present but I expect them to be gone from Vashon within this decade.

This problem is easy to solve: keep your cat in-doors. Not only will that protect wildlife but also it helps the cat. Not letting it out keeps it from fighting and being injured by other cats. It seems like just about every time we have let our cat out here, it catches a bunch of voles and then gets a bunch of parasites and starts dropping worms out of its butt all over the house.

Some other things to do: 1. Neuter your cats so that they don't wander when they do get out and don't propagate more cats. 2. Support groups like VIP (Vashon Island Pet Protectors 206-389-1085) that promote neutering pets and help control and find homes for feral animals. 3. Don't rely on declawing cats or giving them bells, both have been shown to not prevent most cats from killing wildlife.