The reaction arose from a study conducted by the Smithsonian Conservation Biology Institute and the U.S. Fish and Wildlife Service’s Division of Migratory Birds. Published Jan. 29 in the journal Nature Communications, the report crunched numbers from 90 previous studies to conclude that while backyard cats kill their fair share of wildlife, an estimated 80 million farm cats, strays and feral felines are responsible for 69 percent of bird mortality and 89 percent of mammal mortality.
“This study…demonstrates that the issue of cat predation on birds and mammals is an even bigger environmental and ecological threat that we thought,” said George Fenwick, Ph.D., president of the American Bird Conservancy in Washington, D.C.
The Humane Society Veterinary Medical Association noted that the issue “can’t be solved overnight” and must be addressed in “a meaningful way.”
“It is clear that effective solutions to the problems of free-roaming cat overpopulation and wildlife predation will have to include newer and more innovative approaches,” said Barry Kellogg, VMD, the Washington, D.C.-based group’s senior veterinary medical adviser.
Dr. Kellogg pointed to community-based TNR programs as “the most viable, long-term approach available at this time to reduce feral cat populations.”
“Additional research, development of new contraceptive tools…and expanding public education campaigns, especially in relation to encouraging responsible pet ownership that includes spaying and neutering of cats and keeping them indoors, must all be addressed in an effort to prevent further escalation of this issue,” he added.
Educated, responsible cat owners are key to reducing predation, said Bruce Kornreich, DVM, Ph.D., Dipl, ACVIM, an associate director at the Cornell University College of Veterinary Medicine’s Feline Health Center.
Dr. Kornreich agreed with the researchers that domestic cats take a considerable toll on wildlife.
“Given the impact of owned cats on wildlife, educating owners about the importance of keeping their cats indoors is crucial,” he said. “Of equal importance is the necessity of making the cat-owning public understand that when a cat is adopted, this should be considered a commitment for the duration of the life of the cat, which may be between 15 and 20 years. The release of owned cats that eventually integrate with the burgeoning unowned population is a significant problem.”
CATalyst Council, an Annapolis, Md.-based cat advocacy group, stated that the study cast housecats in an unfavorable light and may hamper the ability of shelters to place cats in adoptive homes.
“We regret the fact that the articles written about the study have maligned cats as a whole, when in fact, the vast majority of the estimated destruction to wildlife was reportedly by feral or stray cats,” said Jane Brunt, DVM, the group’s executive director. “This works to discourage prospective cat owners from adopting one of the hundreds of thousands of healthy, enjoyable cats that are held in shelters across this nation.”
The group issued three observations:
• Cats should be kept indoors not only to protect wild birds and small mammals but also for the pet’s safety.
• TNR programs and the development of nonsurgical sterilization methods are deserving of community support.
• Some predation is acceptable. “Remember that some of the killed mammals cited in the study are pests, including mice and rats, which reproduce quickly and pose a public health concern when their numbers are allowed to grow unchecked,” CATalyst Council reported. “By helping to reduce the number of rodents, the cats are performing a valuable service.”
TNR programs keep individual cats from reproducing but are not 100 percent effective at reducing feral populations, said Ken Rosenberg, Ph.D., a conservation scientist at Cornell University’s ornithology laboratory.
“The incredible proliferation of trap-neuter-return programs has produced cat colonies on public lands, fed by volunteers and sanctioned by municipalities,” Rosenberg said. “Instead of the animals dying off, people are dropping off more cats and the colonies are ballooning.”
Rosenberg disagreed with the feline advocacy group Alley Cat Allies, which called the study “bad science” and “part of the continuing propaganda to vilify feral cats.”
“This study is not part of a cat-hating campaign,” he said. “It’s about the inappropriateness of cats having freedom to roam and policies that support the proliferation of top predators on public lands that are wreaking havoc on our native wildlife.”