The Scourge of House Cats

Felines Fatales

With something like 150 million free-ranging house cats wreaking havoc on our wildlife, the last thing we need is Americans sustaining them in the wild.

By Ted Williams

Dusk descends over Honolulu, and from the shadows of bushes and buildings alien predators come in on little cat feet, sitting on silent haunches. But unlike the fog that also hangs over this city, they do not move on. Instead, they wait to be fed.

The University of Hawaii is overrun by feral house cats—more than one per acre—and it smells that way. They are fed by university professors and students, who also trap and medicate them, get them spayed and castrated, then release them. The idea is that the colony will eventually die out without individuals being subjected to the perceived hideous fate of euthanasia. Pioneered in North America at the University of Washington in the 1980s, it’s called Trap, Neuter, and Return (TNR). It’s all the rage across the United States. And it doesn’t work.

David Karl, rare among TNR practitioners in that he understands and advocates for native ecosystems, is one of the main organizers of the feral cat welfare at the University of Hawaii. He is, in fact, an eminent oceanographer and member of the National Academy of Sciences. One of his fellow professors, ornithologist Sheila Conant, who is committed to removing cats from bird habitat, describes him as “a fantastic scientist who brings in gobs and gobs of money.” Karl tells me that after 10 years of effort, about 80 percent of the feral cats on campus have been sterilized and that, therefore, TNR is working. In the same breath he estimates the population at 400.

The feral cats I encountered at feeding stations at Kapiolani Community College and Ala Moana Park, also in Honolulu, looked sick and sad, not that the ones at the university had struck me as perky. Dining with them at the college was a mongoose, another alien scourge, inadvertently sustained by cat feeders. At the park feral cats crouched, slunk, and crunched kibbles all around me, and above me they padded over rooftops.

My guide was Rachel Neville, manager of the Oahu Invasive Species Committee, which has accomplished the monumental task of ridding the island of coquí frogs from Puerto Rico. Her chances of ridding Oahu of feral cats: exactly zero. On this island alone there are 1,200 people registered as feral cat colony caregivers. And from July 1, 2007, to June 30, 2008, the Hawaiian Humane Society sterilized 2,573 feral cats at no charge for 461 people. That sounds impressive unless you consider that 71 percent to 94 percent of a colony needs to be sterilized before there can even be a decline (provided there’s no immigration) and that there are thought to be at least 100,000 feral cats on the island. Moreover, it’s nearly as hard to trap cats as it is to herd them, and welfare programs for feral cats encourage the dumping of unwanted pets.

According to Alley Cat Allies, a Bethesda, Maryland–based group that promotes both TNR and feral cats, there are now more than two hundred 501-C3–registered feral cat organizations dedicated to TNR. Funding—from private donations, the pet industry, and municipalities—is lavish. Alley Cat Allies, for example, has a staff of 25 and an annual operating budget of $4 million. With an endowment of $300 million, Maddie’s Fund (named for a deceased miniature schnauzer) awards large grants for TNR.

Wildlife biologists and law-enforcement officials contend that in most situations feeding feral cats violates federal law because it facilitates “take” of species protected by the Migratory Bird Treaty Act and/or the Endangered Species Act. The take is prodigious. The American Bird Conservancy estimates that 150 million free-ranging cats kill 500 million birds a year in the United States. And according to a peer-reviewed study published February 24, 2009, in Conservation Biology, TNR causes “hyperpredation,” in which well-fed cats continue to prey on bird, mammal, reptile, and amphibian populations so depressed they can no longer sustain native predators.

The political power of wildlife advocates is dwarfed by that of the feral cat lobby. Last year, for example, it squashed federal legislation to remove exotic species from national wildlife refuges because feral cats might be among them. In Hawaii legislation to ban the feeding of cats on state property is invariably shouted down. “TNR advocates are very well organized and funded,” declares Steve Holmer, director of public relations for the American Bird Conservancy. “They’re getting ordinances passed all over the place.”

One of these places is the City of Los Angeles, which has recently embraced TNR and whose animal services manager, Ed Boks, proclaimed on his blog that National Audubon supports TNR. With considerable effort, Audubon’s director of bird conservation, Greg Butcher, got him to remove that gross misinformation. He describes Boks as “one of these people who believes that the only reason you don’t agree with him is that he hasn’t talked to you enough.” Butcher patiently explained the virtual impossibility of trapping and sterilizing enough cats to eliminate reproduction in a colony, and he reminded Boks of all the good wildlife areas in the jurisdiction of Los Angeles. Finally, he cited National Audubon’s board resolution opposing TNR, which reads in part: “Feral cat colony programs, wherein feral cats are captured, trapped, vaccinated, neutered, and fed, do not eliminate predation on native wildlife or reduce the size of feral cat colonies; and . . . bites, scratches, and fecal contamination from feral and free-ranging pet cats pose a risk to the general public through transmission of diseases such as toxoplasmosis, roundworm, and rabies.”

Each time representatives from the environmental community approached the city to remind it that its commitment to TNR required environmental review under California law, they were blown off. Finally, Los Angeles Audubon, Palos Verdes/South Bay Audubon, the Endangered Habitats League, and the Urban Wildlands Group emphasized the request with a lawsuit, now in progress.

One thing the animal-rights community and wildlife advocates agree on is the importance of keeping pet cats indoors. But that’s only half a solution or less because cats have been reproducing in the wild since European contact. For instance, recalling his 1866 visit to Hawaii, Mark Twain wrote: “I saw cats—Tom cats, Mary Ann cats, long-tailed cats, bobtail cats, blind cats, one-eyed cats, walleyed cats, cross-eyed cats . . . platoons of cats, companies of cats, regiments of cats, armies of cats, multitudes of cats.”

The “multitudes” of feral cats that blight America hasten the extinction process. On Hawaii’s Big Island, for example, they depredate about one of every ten nests of the palila—an endangered honeycreeper (see “Last Chance,” Incite, May-June 2009). Ten thousand feet up on Mauna Loa, cats are snatching endangered Hawaiian petrels from their burrows. The single chick can’t fly for 15 weeks, and adults don’t breed until they’re at least five. On Kauai threatened Newell’s shearwaters get disoriented by lights and crash. Usually they’re unhurt, but because they can’t take off from land people pick them up and deposit them in large “mail boxes” at fire stations from which they’re collected and returned to the sea. But feral cats have learned to congregate under the lights, and, increasingly, they’re killing the birds before they can be rescued.

On Maui, where, at last count, the public maintains 110 feral cat colonies, two cats killed 143 wedge-tailed shearwaters in one night. Wedge-tailed shearwaters lay one egg a year after they’re seven years old, and if one parent is killed, the chick dies. One study turned up Hawaiian stilt parts in 12 percent of feral cat stomachs. Scott Fisher of the Maui Coastal Land Trust points out that seabird guano that used to enrich coastal wetlands throughout the state has declined to the point that alien plants are destroying these habitats.

When Fern Duvall, a biologist with the Hawaii Division of Forestry and Wildlife, compared seabird production on main islands and offshore islands where cats were absent, he found 13 percent nesting success on the former, 83 percent on the latter.

Duvall points out that the fact that there are fewer birds in urban areas doesn’t mean TNR is okay in cities like Honolulu. “We finally have the amakihi, one of our native honeycreepers, somehow adjusting to avian malaria,” he says. “This is the thing everyone’s been waiting for, a forest bird adjusting to introduced disease. They’re recolonizing former habitat in Honolulu only to be taken out by feral cats.”

Although feral cats elsewhere in the nation must contend with coyotes, foxes, fishers, bobcats, and harsh winters, they frequently outnumber all native, midsized mammalian predators combined and compete with them and raptors for prey. This is the case in Wisconsin, where, in the late 1980s, the U.S. Department of Agriculture and the state Department of Natural Resources fretted that in creating new habitat for declining grassland birds they were funneling them into cat gullets. Accordingly, they commissioned Stanley Temple, then a wildlife ecologist at the University of Wisconsin-Madison, to undertake a major field study of feral cats.

Temple surveyed 1,200 landowners in rural Wisconsin, finding that feral cats, if they can be called that in a place where winters force dependence on humans, live in barns, scavenging and with no vet care. Most pet cats, he learned, were allowed to hunt outdoors. The data provided an accurate estimate of at least 1.4 million free-ranging cats in rural Wisconsin. And from observing cats he’d radio-collared and examining scats and stomach contents (the latter obtained with a mild emetic), he got an accurate estimate of between five and six birds killed per cat per year. That means that cats were annually knocking off somewhere in the neighborhood of 8 million birds just in rural Wisconsin.

It got so bad that in 2005 the Wisconsin Conservation Congress—a purely advisory entity sired by Aldo Leopold to ensure public participation in DNR decision making—considered a proposal to recommend that free-ranging cats be placed on the unprotected list along with skunks, starlings, and the like. At hearings in 72 counties the proposal was supported by a majority of the public. It was hardly a radical notion because cats have long been classified as unprotected wildlife in other states. It wasn’t even necessary because there had never been a Wisconsin law against drowning or shooting problem cats on one’s own property.

Still, cat lovers caterwauled. Failing to grasp the difference between game protected by seasons and bag limits and unprotected nongame, the press wrongly reported that the state was considering opening a hunting season on house cats. One inflammatory piece, in the Wisconsin State Journal, was used in a Society of Environmental Journalists workshop as an example of how to warp news. The din ultimately induced Governor Jim Doyle to issue a proclamation that cats wouldn’t be hunted in Wisconsin.

In all his research Temple never killed a cat. He never advocated cat removal. He never took a position on placing cats on the unprotected list. But because his data had been cited by wildlife advocates some cat lovers confronted him with hysterical shrieking sufficiently sustained to preclude response. Others vowed to kill him. One woman, recorded on his answering machine, hissed: “You cat-murdering bastard. What goes around comes around. I declare Stanley Temple season open.”

Such is the mindset of feral cat lovers across the country. “It’s like a religion,” remarks Fern Duvall, who also gets death threats. “You can’t sit down and reason with most of these people.” Facts are dismissed, data denied, suffering of wildlife and cats ignored. For example, the official policy of the No Kill Advocacy Center of Oakland, California, is that feral cats must be protected as “healthy wildlife.” The Santa Monica–based Voice for the Animals Foundation even stocks feral cats (supposedly for rodent control). Elizabeth Parowski, communications manager for Alley Cat Allies, informs me that the American Bird Conservancy’s estimate of 500 million birds annually killed by free-ranging cats (conservative because some estimates place the figure at a billion) is “conjecture and the conservancy admits that.” But when I ran her statement by Steve Holmer, he explained that the estimate is based on excellent data from the pet industry and extrapolations by researchers like Temple. Dismissing Temple’s statistics, Parowski said: “I know about his work. It’s never been peer-reviewed, never been published.” It was subjected to extensive peer review and has been published many times, originally in the Wildlife Society Bulletin, a scientific journal.

“Feral cats are territorial,” Parowski continued. “They will keep other cats from moving into their territories. That’s why trap and kill is so ineffective—because of the vacuum effect.” Without exception I got the same line from every TNR outfit I consulted. It’s rubbish. “The very fact that you can create a feral cat colony tells you they’re not territorial,” says Temple.

Last year Hawaii Audubon Society president John Harrison attempted to penetrate the feral cat mindset by hosting a presentation by the state’s seabird, shorebird, waterbird coordinator, Norma Bustos. “No amount of exposition of rational facts could sway the cat lobby,” he told me. “Norma was very calm and even-handed.” Still, cat lovers screamed at her after she showed photos of cat feces full of bird bands, Hawaiian petrels decapitated by cats, cat-mangled wedge-tailed shearwaters, and a video of a cat dragging a palila chick from its nest. Attendees trotted out the old fairy tale that if more people fed feral cats, they wouldn’t eat birds. When Bustos suggested that pet cats should be kept indoors, a cat lover angrily intoned: “If you’re so worried about the birds, you should keep them indoors.”

When I met with Bustos at the town of Kailua she expressed as much concern about damage to wildlife by cat diseases as cat claws and teeth. About 73 percent of feral cats in her state are infected with toxoplasmosis, a parasite that sheds oocysts into the bowel. Cats are the only vector. Copious oocyst-laden cat feces is killing red-footed boobies and endangered nene geese. When the disease started killing endangered Hawaiian crows, all birds had to be evacuated from the wild and now must be maintained in captivity. Endangered monk seals have died from it. It’s nearly as bad in other states. Cats have passed toxoplasmosis to harbor seals, California sea lions, and sea otters. One study found toxoplasmosis in 42 percent of live sea otters and 62 percent of dead ones.

In humans toxoplasmosis damages embryos, causing infant mortality, cerebral palsy, blindness, mental retardation, and other birth defects. Recently Bustos visited a feral cat feeding station at an Oahu water park. She reports that the place reeked of cat urine and that cat feces could be fouling the pool in which kids and pregnant women were swimming. Feral cats are also transferring roundworms, hookworms, and ringworm (a fungus infection) to humans and wildlife. In Florida 75 percent of feral cats studied had hookworms and 93 percent had fleas, which pass such diseases as Bartonella, Ricksettia, and Coxiella between animals and humans. About 80 percent of rabies shots administered to humans result from contact with feral or stray cats. Feral cats spread the feline leukemia virus to cougars and possibly feline distemper and an immune deficiency disease to endangered Florida panthers. Stanley Temple was recently delighted to find a denning bobcat on his property. When all the kittens died he had them autopsied. “They’d succumbed to feline distemper,” he told me. “The only source in the area is free-ranging house cats. The mother may have killed some.”

If there’s one animal-welfare group that deserves respect, it’s the Humane Society of the United States. It doesn’t pretend that feral cats don’t suffer or that they don’t kill wildlife or transmit dangerous diseases. In 1992 it offered this excellent advice: “Responsibility means rescuing the cats and either taming them and placing them in homes, or humanely ending their lives, but nothing short of either.” But now the Humane Society touts TNR. Why the flip-flop, I asked CEO Wayne Pacelle. “The labor that the TNR folks invest is beyond formidable,” he replied. “I thought it was better to work with them, and to encourage others to actively manage these populations, than to simply will this away. I’d rather have managed colonies than unmanaged, and those are the two primary options, based on my experiences and observations.”

Some Audubon chapters agree. They’ve settled for TNR, but not because it’s a good idea. The City of Cape May, New Jersey, with some of the most important shorebird habitat in the nation, recently passed an ordinance permitting TNR—this to the horror of the New Jersey Audubon Society, which fiercely opposed it. Town after New Jersey town followed suit. Finally, with the battle clearly lost and facing the “option to do something instead of nothing,” as Eric Stiles, vice president for conservation and stewardship, puts it, New Jersey Audubon began working with and thereby marginally controlling TNR practitioners. Thus was born the New Jersey Feral Cat Wildlife Coalition, in which sponsors of feral cat colonies agree to keep the colonies away from nesting areas (though cats can get there easily enough). In Cape May, at least, sterilization rates are probably higher than any other TNR program in the nation.

Forty percent of the birds that Bob Sallinger, conservation director of the Audubon Society of Portland, Oregon, treats at his rehabilitation center are cat victims, and few survive. He hates putting cats back into the wild, but he has hatched a partnership with a TNR group called the Feral Cat Coalition. It’s worth it, he opines, if the partnership puts out a unified message that pet cats need to be kept indoors and if the caretakers keep their promise to keep TNR colonies away from natural areas.

These alliances were high-profiled in the Humane Society’s March-April 2009 All Animals magazine. The piece is well written and sincere, but the message is wrong. Attempting damage control by collaborating with TNR groups may occasionally be necessary, but it’s hardly something we should feel warm and tingly about or promote as a final goal. The authors of the February 24, 2009, Conservation Biology piece explain why: “Published research has been distorted by TNR proponents with little response from the scientific community, perhaps in part because TNR has been approached largely as an animal welfare issue instead of being recognized as a broad environmental issue with a range of impacts on species conservation, the physical environment, and human health.”

In rural areas where feral cats are killing threatened or endangered wildlife, sometimes the only practical way for state or federal management agencies to deal with them (and therefore the way required by the Endangered Species Act) is for animal-control professionals retained by state or federal resources agencies to shoot them in the head with rifles, a form of euthanasia approved as humane by the American Veterinary Medical Association. This approach is certainly kinder to the cats than stressing them with traps, transport, and eventually and almost inevitably lethal injection at shelters.

Another cooperative effort profiled by the Humane Society is its recent agreement with the U.S. Fish and Wildlife Service to care for feral cats the agency traps from 14,500-acre San Nicolas Island off the California coast. Despite a prolonged national stink during which the service received roughly 6,000 public comments, all the cats have to go because the U.S. Navy, which owns the island, is committed to protecting wildlife on all its properties and therefore forbids TNR. Cats are decimating seabirds as well as federally threatened island night lizards and western snowy plovers. They’re also depressing the endemic deer mice that sustain the state-threatened San Nicolas Island fox.

Feral kittens can be converted to pets, but adults have great difficulty adapting to captivity. Still the Humane Society has agreed to take trapped adult cats from the island and maintain them indoors for the remainder of their lives. The Fish and Wildlife Service claims that it will use live trapping as its “primary removal method.” But in what it calls a “pilot program,” in late 2008 and early 2009 the service succeeded in trapping only seven cats, and no one who knows feral cats believes that the vast majority won’t be controlled by the service’s little mentioned, secondary method—the rifle.

Like so many of his colleagues, Fern Duvall would like to see cities, states, and federal agencies follow the Navy’s enlightened example. In fact, he wants people who feed feral cats prosecuted under the Migratory Bird Treaty Act and/or the Endangered Species Act. But the departments of Justice and Interior lack the stomach. “There’s still a disconnect between the lower and higher echelons when it comes to hot political issues,” says Duvall.

That kind of timidity sacrifices wildlife, betrays the public, ignores the Fish and Wildlife Service’s mandate, and flouts federal law. To borrow Duvall’s analogy, it’s as if 19th century legislators had declared, “Well, American women really want those millinery feathers, and we’re just not going to bother with that.” But those legislators yielded to the tough, tenacious founders of the Audubon movement in the early 1900s, and the feather trade was permanently shut down. That example seems lost on today’s wildlife advocates, at least when it comes to dealing with the feral cat lobby.

“Unfortunately, the cat people have an emotional appeal with the public that’s superior to anything we bird people have,” says Audubon’s Greg Butcher. “We just have to take this free-ranging-cat problem head on.” That’s not going to be easy or pretty. Sterilizing pet cats and keeping them indoors, caging feral cat colonies, and even lethal control won’t solve the problem. These measures are, however, the best we can do, and they will help a lot.

WHAT YOU CAN DO

For instructions on how to break your cat’s outside habits, go to the American Bird Conservancy’s Cats Indoors! campaign. Cat “bibs” can help save birds; see Field Notes, January-February 2008. Push for the permanent removal of free-ranging cats near natural areas. Speak out against TNR, especially municipal ordinances.

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--Audubon, Sept. 2009; http://www.audubonmagazine.org/incite/incite0909.html