What do feral and free-roaming house cats do when they’re out of sight? University of Illinois researchers – and many cat-owners – wanted to know. A two-year study using sophisticated tracking devices followed 42 cats on the outskirts of the cities of Urbana and Champaign in Central Illinois. The study found that one feral male roamed widely over 1,351 acres, while pet cats stayed closer to home, with a mean range of just under 4.9 acres. Results of the study were published in the April 21, 2011 online issue of The Journal of Wildlife Management.
Jeff Horn, a former graduate student in the University of Illinois Department of Natural Resources and Environmental Sciences, collaborated with colleagues from his department, along with the Prairie Research Institute and the Illinois Natural History Survey, on a two-year study of pet and feral outdoor cats. The researchers used radio telemetry and collar-mounted activity sensors to capture the haunts and habits of dozens of pet and feral cats with overlapping urban, suburban and rural territories. Together, the 42 adult cats ranged over a territory of 6,286 acres (2,544 hectares).
Of the radio transmitters used in the study, 23 had tilt and vibration sensors that tracked the animals’ every move. Horn said:
There’s no … data set like this for cats. Without these sensors, it would require a field team of 10 to 12 people to collect that data.
As expected, in most cases the feral cats had larger territories than the pet cats and were more active throughout the year. But the size of some of the feral cats’ home ranges surprised even the researchers. The feral cat with the largest range of 1,351 acres was a mixed-breed male seen in both urban and rural sites, from residential and campus lawns to agricultural fields, forests and a restored prairie.
That particular male cat was not getting food from humans, to my knowledge, but somehow it survived out there amidst coyotes and foxes. It crossed every street in the area where it was trapped. It navigated stoplights, parking lots. We found it denning under a softball field during a game.
The pet cats had significantly smaller territories and tended to stay close to home. Even though the mean home range for pet cats in the study was less than 4.9 acres…
… some of the cat owners were very surprised to learn that their cats were going that far. That’s a lot of backyards.
The pet cats managed this despite being asleep or in low activity 97 percent of the time. On average, they spent only three percent of their time engaged in highly active pursuits, such as running or stalking prey, the researchers reported. The feral cats were highly active 14 percent of the time.
The un-owned cats have to find food to survive, and their activity is significantly greater than the owned cats throughout the day and throughout the year, especially in winter. These un-owned cats have to search harder to find food to create the body heat that they need to survive.
The cats also differed in the types of territories they used throughout the year. Pet cats randomly wandered in different habitats, but feral cats had seasonal habits. In winter, feral cats stayed closer to urban areas than expected. And throughout the year, they spent a good amount of time in grasslands, including a restored prairie.
Most of the cats in the study stayed within about 300 meters of human structures, said co-author Nohra Mateus-Pinilla, a wildlife veterinary epidemiologist at the Illinois Natural History Survey at Illinois:
Even feral cats were always within range of a building. That shows that even though they’re feral, they still have a level of dependency on us.
One feral cat chased another out of a dairy barn. Another feral cat waited for a pet cat to emerge each morning and tried to chase it out of its own backyard, Horn said. This overlap of feral and pet cat territories outdoors spells trouble for the environment, the cats, and potentially for cat owners, the researchers said.
In an earlier study, co-author Richard Warner followed the cats of about two-dozen rural residences over several years. He said:
Two of the leading causes of cat deaths in that study were other cats and disease. And both of these leading causes of death are sitting here waiting for these owned cats outdoors.
Mateus-Pinilla said that cats also get diseases from wildlife or other cats and can bring them home and infect their owners and other pets. She gave an example:
Toxoplasma gondii, a parasite spread primarily by cats, may cause neurological, reproductive and even respiratory problems in humans, cats and wildlife, depending on the species affected.
According to Mateus-Pinilla, rabies, cat scratch fever, feline leukemia and feline immunodeficiency virus are also of concern to pet owners whose cats encounter other cats outdoors. Vaccination of pet cats will reduce but not eliminate the threat of disease transmission.
The researchers explained that pet cats — even though they have relatively small ranges and are active only in short bursts — have a much more intense impact on wildlife in the immediate vicinity of their homes than do feral cats that wander over a larger territory. Unlike other feline predators, such as bobcats, which are native to the Midwest, domestic cats are an invasive species with a disproportionately damaging effect on wildlife -– either through predation or disease. Wild animals that have adapted to ecosystems that are already fragmented, such as the prairies of Central Illinois, are even more endangered because domestic cats are disrupting the ecosystem by hunting, competing with native predators or spreading disease.
Bottom line: A two-year study, published in the April 21, 2011 online issue of The Journal of Wildlife Management used sophisticated tracking devices to follow the movement of feral and pet cats on the southern edge of Urbana and Champaign,
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