INSIDE, OUTSIDE, OR BOTH--WHERE SHOULD CATS STAY?

by Whit Gibbons

July 31, 2011

Killer cats roam the country and the world. I am not referring to superstars like tigers, lions and leopards, simply to the common house cat. Between feral cats and those with owners who let them outside on a regular basis, cats kill 20 million birds each year in Britain. Another published report estimated the annual wildlife toll from cats in Virginia to be at least 3 million songbirds and 27 million native mammals. Another study recognized feral cats as the greatest nonhuman cause of mortality to some Australian wildlife.

A cat lover might quibble over the actual numbers but surely not the essence. Outdoor cats kill lots of native wildlife wherever they are. But whether cats should stay inside permanently or be permitted outdoors regularly is a volatile issue that will never be resolved to everyone's satisfaction. Many people tend to take an inflexible position about the proper place for a cat's whereabouts. Social gatherings go more smoothly if opinions about cats go unstated. Otherwise, you might end up in a discussion about whether Susiebelle should let her cats out to pillage wildlife in their heartless way or why Tom, Dick, and Harry keep their cats imprisoned in a stuffy apartment condemned to a lifetime of boredom and inactivity. A recent scientific article in the Journal of Wildlife Management provides information on the topic of free-roaming cats.

Jeff A. Horn, at the University of Illinois, and colleagues addressed what the home range, habitat use and activity patterns were of outdoor cats, but with a different twist. The study is a mixture of ecology and behavior with practical applications for wildlife management; it should also be of interest to laypeople, whether they keep cats or not. The researchers compared feral cats that are ownerless nomads with the home-grown variety that live inside most of the time and go out whenever their owners decide it is time. They used collar radiotransmitters to track where outdoor cats went. To determine how much time a cat spent wandering, how much time napping and how much time actually hunting, they used movement-sensing transmitters that registered activity.

Some of the findings were not surprising. Feral cats, which have no owners and have to find their own food, were more active throughout the year and shifted to different habitats as the seasons changed. The behavior reflected a need for subsistence hunting to capture prey that was a staple for survival. A domestic cat has the luxury of recreational hunting, catching whatever happens to be in the front yard during an outing. My interpretation is that domestic house cats are lazy most of the time when they are outside. Anyone who has an indoor cat already knows this to be true when they are inside.

Feral cats were also more likely than domestic cats to be active at night. The investigators speculated that nocturnal behavior would allow greater opportunities for finding prey and provide less chance of encountering humans. Of course, the time of day that domestic pets are outside reflects the behavior of the owner as much or more than that of the pet. Probably lots of house cats end up indoors at night because the family routine includes bringing pets inside before bedtime.

Not surprisingly the projected survivorship of a feral cat with no permanent home and no caretaker was substantially below that of its feline counterparts that had the protection of a house and humans. Two feral cats were killed by coyotes and several inexplicably disappeared, whereas the only mortality to a domestic cat during the study was under the front wheel of a moving car. Survival estimates showed that half the feral cats in the study were likely to die within 13 months whereas 90 percent of the domestic cats were still alive after more than 19 months.

This latest study provides some interesting new perspectives on just what domestic cats do if they are permitted outside. But I am still keeping my opinion about indoor versus outdoor cats to myself at parties.

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