VICTORIA -- Canada's 7.9 million house cats are the focus of intensifying public disquiet. There are those who loudly protest catastrophic predation by cats on wildlife and demand cat control. Others vociferously oppose any sort of cat constraint owing to their unique and iconic status that should exempt them from municipal oversight.
The controversy is pitting neighbour against neighbour.
At issue are the results of many studies confirming that more than two-thirds of house cats are permitted to prowl outdoors. Their hunting activities have been documented, confirming they destroy about 110 million songbirds each year in Canada and the United States, roughly 10 per cent of the total figure in Canada. But accumulating information suggests the actual mortality could be substantially higher still.
A 1987 study in the U.K. by Peter Churcher and John Lawton indicated on average, each house cat at large kills roughly four songbirds a year. That figure, which has since been substantiated, indicates the cat-caused songbird loss in Canada could be as high as 20 million a year.
Several regional and local studies indicate songbird mortality due to cat predation can be very high. Stanley Temple at the University of Wisconsin documented that house cats on the loose destroy 19 million songbirds annually in Wisconsin. Some newer estimates of the total North American songbird toll due to cat predation could top three billion annually.
According to the Humane Society of the United States, outdoor time is not a prerequisite of cat happiness.
Several studies have shown well-fed house cats are just as destructive of wildlife as are hungry cats. Research indicates this is because cats hunt largely for amusement. Neurological studies have confirmed hunting for food and hunting for sport are activities controlled in cats by different and independent parts of the feline brain.
Despite irrefutable evidence confirming the scope of wildlife mortality caused by cats on the prowl, there is widespread denial by cat-fanciers, according to evidence accumulated by the National Wildlife Federation.
Some cat owners claim they allow their cats outdoors to help rid the neighbourhood of mice. But studies suggest even if cats do reduce local mouse numbers, their hunting cuts the opportunity for local hawks and owls to catch and eat mice. Raptor nest density in areas regularly prowled by house cats is significantly lower than in areas where the birds do not have to compete with cats.
It is a common fallacy that belling house cats can prevent songbird predation. But domestic cats are not native to North America, and consequently, wild birds lack a natural fear of the animals. As well, decades of research has shown birds do not link the sound of a tinkling bell to pending danger.
In addition to their destruction of wildlife, cats are also under fire on account of their extraordinary reproductive rate. Some urban areas are overwhelmed with cats.
According to the Society for the Prevention of Cruelty to Animals, "cats can't add but they sure can multiply."
House cats, when allowed outdoors, regularly interbreed with local feral cats, and the resulting hybrid cat population preys on wild birds to the degree that up to two-thirds of their regular diet comprises songbirds.
Owing to the major impact cat predation can have on local songbird numbers, the matter of cat control has surfaced on the agendas of municipal authorities across Canada. Politicians are sensitive to the possibility of public furore over the notion of any kind of cat control. That is because cats have a special place in the hearts of cat owners to whom the concept of cat control is abhorrent. Since about 40 per cent of Canadian households have at least one cat, the scope of outrage could be very substantial.
Even so, several Canadian municipalities have taken bold steps in that direction.
In early April, Victoria, B.C., became the most recent municipality in which there have been suggestions by members of the public that cat licensing would be wise, owing to "the impact that cats can have on our environment."
In 2007, Calgary put in place mandatory cat licensing, and required that house cats be kept indoors or leashed when outside. Since then, 50,000 cats have been licensed and the number of euthanized strays has been cut in half.
Toronto's municipal code requires all house cats to be licensed -- there are 323,000 house cats in Toronto.
In Kingston, Ont., all cats more than 20 months of age must be registered. Recently, Hamilton pondered taking similar steps but backed off owing to anticipated public opposition.
Although Canada's wild birds are protected by federal and provincial legislation, there are no laws prohibiting cats from killing wild birds. Cat owners are off the hook if their felines kill wild birds because they can claim their pets were let outdoors to kill mice not birds.
There are close to 220 million house cats in the world. But very few politicians have ventured into the minefield of cat licensing, cat neutering or any other kind of cat constraint, even though dog control has a long history.
That is because, as the old adage points out, "you can own a dog... but your cat owns you."
Robert Alison is a zoologist and freelance writer based in Victoria, B.C.