Laura Erickson's For the Birds

Last time I answered a couple of questions from a woman named Barbara, who also asked me what to do about cats. She happens to have indoor cats who cannot get near the birds in her yard, although as she points out, they’d love to. But she wonders how she can keep roaming neighborhood cats from stalking birds at her birdbath and feeders. She doesn’t want the birds to unwittingly be bait for other animals.

Barbara’s is certainly an important concern. There is an abundance of data establishing that cats are responsible for severe population losses in several species. According to the American Bird Conservancy, nationwide cats are estimated to kill hundreds of millions of birds and more than a billion small mammals such as rabbits, chipmunks, squirrels, and shrews every year. Cats not only kill plentiful animals but rare and endangered species for which the loss of even one animal is significant. The scientific community is increasingly concerned about cat predation. One regularly fed cat that roamed a wildlife experiment station was recorded to have killed more than 1600 animals, mostly small mammals, over 18 months.

Rural cats take more prey than urban or suburban cats. Birds that nest on the ground are the most susceptible to cat predation, as are nestlings and fledglings of many other species. But suburban and urban cats do their worst work at feeders, where some individuals can kill several individuals every day, especially during migration and winter, when birds can be very concentrated.

The ancestors of our domesticated cats were natural predators in their native land of Africa and extreme southwestern Asia, but since their domestication in Egypt, they’ve been subsidized by humans and cannot be considered part of any natural ecosystem. Being subsidized means that we humans provide them with food and veterinary care, so they are not subject to the same controls as natural predators. It also means that they can take a far greater toll of prey species than any natural predator could and remain in an area.

In my own yard back before Duluth established a cat leash law, I was cat-free most of the time because my dog chased them away. The exception was a hungry stray that I took in. I’ve taken in several strays in my lifetime, and without exception they were so grateful for a home that they never seemed to mind being kept indoors permanently. House cats are safe from exposure to feline leukemia, distemper, rabies, and automobiles, to say nothing of skunks, dogs, and other cats.

Many people do not realize that cats who toy with birds are the ones likely to carry toxoplasmosis, which is very dangerous for pregnant women and newborns. If your city doesn’t have a cat leash law, it should, not only to protect birds but to protect human beings and the cats themselves. Outdoor cats often use small children’s sandboxes as litter boxes, and cats outdoors have a much shorter lifespan than cats kept inside all the time. If you know the owners of a stray cat, it’s often difficult to approach and ask them to keep the cat indoors, but if you don’t have a dog to chase it away, it might be a good idea to talk to these people about it, using solid information rather than anger to make your point. Cats belong indoors.