Keep cats inside to preserve health, local ecosystems
(University of Maryland) - The next time you crack your backdoor to let your cat outside for its daily adventure, you may want to think again. For a cat, the outdoors is filled with undesirable potential. Like the risks of catching and transmitting diseases, and the uncontrollable drive to hunt and kill wildlife, which has been shown to reduce native animal populations and degrade biodiversity.
A new study by University of Maryland researchers has concluded that humans bear the primary responsibility, and that these risks can be significantly reduced by keeping cats indoors. The study’s analysis used data from the D.C. Cat Count, a Washington, D.C.—wide survey that deployed 60 motion-activated wildlife cameras spread across 1,500 sampling locations. The cameras recorded what cats preyed on and demonstrated how they overlapped with native wildlife, which helped researchers understand why cats and other wildlife are present in some areas, but absent from others. The paper was published on November 21, in the journal Frontiers in Ecology and Evolution.
“We discovered that the average domestic cat in D.C. has a 61% probability of being found in the same space as racoons — America’s most prolific rabies vector — 61% spatial overlap with red foxes, and 56% overlap with Virginia opossums, both of which can also spread rabies,” said Daniel Herrera, lead author of the study and Ph.D. student in UMD’s Department of Environmental Science and Technology (ENST). “By letting our cats outside we are significantly jeopardizing their health.”
In addition to the risk of being exposed to diseases that they can then bring indoors to the humans in their families (like rabies and toxoplasmosis), outdoor cats threaten native wildlife. The D.C. Cat Count survey demonstrated that cats that are allowed to roam outside also share the same spaces with and hunt small native wildlife, including grey squirrels, chipmunks, cottontail rabbits, groundhogs, and white footed mice. By hunting these animals, cats can reduce biodiversity and degrade ecosystem health.
“Many people falsely think that cats are hunting non-native populations like rats, when in fact they prefer hunting small native species,” explained Herrera. “Cats are keeping rats out of sight due to fear, but there really isn’t any evidence that they are controlling the non-native rodent population. The real concern is that they are decimating native populations that provide benefits to the D.C. ecosystem.”
In general, Herrera found that the presence of wildlife is associated with tree cover and access to open water. On the other hand, the presence of cats