Those of a certain age and from certain not-too-big cities will recall when outdoor cats were commonplace. In the not-so-big Midwestern city of my childhood, there was at least one outdoor cat on my three block walk to school. He was an orange tabby, apparently with no other friends, judging by how he jogged over for a scratch when I walked past his house.
One problem with this, of course, is that there were then and still are dangers for outdoor cats. While coyotes weren’t common in that time and place, cats were frequently seen dashing across city streets, not always successfully. And cats frequently shared the outdoors with not-always-feline-friendly dogs.
Now, as a cat owner, the major disincentive to having cats that go outdoors is the propensity of outdoor cats to move down the street to the neighbors. As you may know, cats frequently need more attention than one person can provide. Or the food at home isn’t quite as good as that offered down the street.
And as recent research from the University of Illinois-Champaign points out, outdoor cats pose significant threats to birds and small mammals, not to mention other cats. Outside cats can transmit potentially serious diseases.
In an attempt to quantify the effects of outdoor cats, University of Illinois-Champaign researchers studied cats with and without owners. For their report in the Journal of Wildlife Management, Home Range, Habitat Use, and Activity Patterns of Free-Roaming Domestic Cats” (1), cats were fitted with radio collars in order to determine differences: 1) between the size and location of the cats’ home range (to determine impact on wildlife); and 2) in daytime versus nighttime activity.
In addition, the researchers hypothesized that cats with owners would have greater shortterm survival than ownerless cats.
The study period was from January 2007 through May 2008, and covered 6 habitat types: grasslands, forests, low-density urban areas (such as residential neighborhoods), high-density urban areas (industrial sites, roads, parking lots), farmsteads and croplands (corn and soybeans).
Forty-two cats participated in the study, 24 ownerless cats (11 male, 13 female) and 18 owned cats (8 males, 10 female).
This study, as previous studies, described larger home ranges for cats without owners, most likely due to the need to forage and hunt (no owner equals no guaranteed food source). Horn et al. noted that the larger home ranges of ownerless cats equated to a greater negative impact on prey species. Disease transmission potential is also greater for the more widely wandering cats. In particular, the researchers commented on the potential for spread of toxoplasmosis by cats.
This link from the Cornell Veterinary School provides good information about Toxoplasmosis in cats.
Counter to what we have heard about neutered cats staying closer to home, Gutilla and Stapp (2; 2010) did not find significantly different home range sizes between neutered and unneutered ownerless cats.
In this study, male cats did not have significantly larger home ranges than female cats. However, female cats were found to share habitats with other female cats, while male cats were found to be more solitary.
Different sizes of home ranges may reflect age and social status of male ownerless cats. Availability of shelter and prey also probably affects home range size of ownerless male cats.
Ownerless cats were most active during nighttime, most likely due to prey activity and the opportunity to avoid human activity. Owned cats activity was lower overall from their ownerless counterparts and most likely tied to their owners’ activity, with more activity in early mornings and evening when owners are preparing for and returning from work.
In addition, the research showed large differences in overall activity levels for cat with owners versus cats without owners; the cats without owners spent 14% of their time in high activity pursuits, compared to 3% of time in high activity for cats with owners. Pet cats spent as much as 97% percent of their time sleeping or in low activity pursuits such as grooming, compared to 86% for ownerless cats.
For the cat owners out there, this is not new information, that our pets spend 97% of their time sleeping or grooming themselves.
Survival analysis for this study showed that 50% of ownerless cats were expected to die within 392 days, whereas 92% of pet cats were alive after 596 days of observation.
While it’s hard to imagine my house cats having an impact on wildlife, I have seen the neighbor’s cat catch and kill a chipmunk. There is no doubt these primary carnivores are good hunters.
I don’t want to have to go to the neighbors to visit my cats, so despite their requests to go out, they’ll be staying in the house. The kids walking by on their way to school will have to walk up to the screened windows.
- Horn, J.A., Mateus-Pinilla, N., Warmer, R.E., Heske, E.J. (2010) Home Range, Habitat Use and Activity Patterns of Free-Roaming Domestic Cats. Journal of Wildlife Management 9999(xx) 1-20; DOI: 10.1002
- Gutilla, D.C., Stapp, P. (2010) Journal of Mammalogy 91, 482-9.