Refer: David Klinger
During "International Migratory Bird Week," A New Internet Publication to Help Pet Owners Become Wiser Wildlife Conservationists
Twenty-five centuries later, Aesop's question continues to perplex wildlife managers and pet owners alike, faced with the dilemma of curbing the effect of America's growing feral feline population on declining populations of songbirds, waterbirds, and small mammals, including those in rapidly urbanizing areas of Pacific region states.
And it is a particularly appropriate question during this, the fifth national observance of "International Migratory Bird Week," May 4 through 10, as amateur bird watchers and professional ornithologists alike review the state of North America's bird populations, faced with a number of threats throughout the hemisphere.
First, let it be acknowledged: some of our best friends are cats ... and dogs, for that matter. It is indeed possible to be both wildlife conservationist and responsible pet owner. Fish and Wildlife Service employees are some of the best at both. America's love affair with domestic cats and its fascination with birds need not be mutually-exclusive infatuations.
But it is no secret that feral cats -- particularly those who have been abandoned and allowed to revert to a wild state by careless owners -- pose serious threats to some of the Pacific region's most highly endangered mammals and ground-nesting birds. In fact, predation by feral cats and non-native, introduced predators has been a primary cause in the growth of the Federal endangered and threatened species list in recent years.
Yet pet predation on rare birds and mammals could be one of the easiest threats to eliminate. The solution lies not in additional government regulation, but in personal responsibility -- a remedy on which most wildlife managers and animal advocates can agree.
A new publication by the University of Wisconsin-Madison, supported with funds from the U.S. Fish and Wildlife Service's National Conservation Training Center, reviews the issue and presents several constructive steps that pet owners can take to minimize the problem and to continue to enjoy the pleasures that cats and wild birds bring to our lives. Cats and Wildlife/A Conservation Dilemma, a new, six-page brochure reviews the impact that uncontrolled predation poses on wildlife and recommends simple solutions to the problem that Aesop noted long-ago in the hills overlooking Athens.
It suggests that the solution need not come from government, but through individual initiative, public awareness, and responsible pet ownership. The brochure encourages pet owners to keep only as many pet cats as can be properly cared for, to confine cats indoors to discourage their tendency to roam and to stalk wild animals, and to neuter pets as a deterrent to unwanted reproduction.
Additionally, the brochure recommends against both the feeding of stray cats and the disposal of unwanted animals by releasing them into the wild -- the latter a problem noted on more than one national wildlife refuge. Maintaining colonies of free-ranging or feral cats encourages high densities of animals that kill and compete with native wildlife, while release into the wild subjects cats to disease and physical injury.
Wildlife and pets. Issues arising from their incompatibility are as ancient as antiquity and as current as today's politics ... and as touchy as any issue that blends people, animals, and public policy.
Adlai Stevenson confronted it in 1949 as governor of Illinois, writing, "The problem of cat versus bird is as old as time. If we attempt to resolve it by legislation who knows but what we may be called upon to take sides as well in the age old problems of dog versus cat, bird versus bird, and even bird versus worm?"
Faced with a particularly contentious bird protection law, future Presidential candidate Stevenson took the expedient route ... and vetoed the Illinois Legislature's bill.
But resource managers don't possess the luxury of the line-item veto when it comes to wildlife problems. And they say the growth in America's feline population -- estimated to have doubled since 1970 to 60 million cats -- coupled with the rapid urbanization of areas that previously afforded sanctuary to wildlife populations, makes this an especially vexing problem.
"Cats are our companions and are popular pets for nearly 30 percent of American households," says Professor Scott Craven of the University of Wisconsin's Department of Wildlife Ecology. "In order to have and care for our pets -- and still protect our native wildlife -- we must make an effort to limit in a humane manner the adverse effects free-ranging cats can have on wildlife." Craven joined colleagues Stanley Temple of the University of Wisconsin-Madison and John Coleman of the Great Lakes Indian Fish and Wildlife Commission, the principal authors of the new publication.
The effects they cite have helped land several species on the endangered species list. They have caused experts to estimate the annual toll on birds from rural cats at several hundred million ... and on small mammals, an astounding one billion a year! While many of these kills are house mice, rats, and other pests, a significant share are native songbirds and other wildlife whose populations are already stressed from habitat decline and pesticide pollution.
Endangered Species Affected
Nowhere along the Pacific coast is the problem as acute as in San Francisco Bay, where several national wildlife refuges spotted along the perimeter of the intensely urban shoreline face problems from feral cats and the non-native eastern red fox, an alien species introduced to California in the last century. Locally these predators threaten at least three imperiled ground-nesting birds and an endangered mammal -- the California clapper rail, the California least tern, the western snowy plover, and the salt marsh harvest mouse.
Wildlife biologist Joy Albertson of the Don Edwards San Francisco Bay National Wildlife Refuge noted the declines in clapper rail populations due to cats and foxes as she studied predators in south San Francisco Bay during academic investigations in the early 1990's. The clapper rail, a secretive denizen of the salt marsh, is found nowhere else in the world except San Francisco Bay tidal marshes. One clapper rail, fitted with a radio telemetry device as part of the research study, was, itself, killed by a feral cat, and biologists continue to observe cats frequently stalking rails in area marshes.
Sightings in 1991 in a marsh complex managed cooperatively with the City of Palo Alto detected either one or two cats in the marsh or along levees in six of 10 nighttime surveys; by 1992, those numbers had jumped -- up to five cats in eight of 11 evening surveys. In four other marshes more distant from residential neighborhoods, however, the number of cats was lower.
Says Albertson, "Feral cats are a serious and increasing threat to endangered species in the Bay area and in other urban areas where sensitive wildlife habitat is close to residential housing and pets."
Elsewhere in the Bay area, California least terns facing cat and fox predation abandoned their nesting colony on the grounds of Oakland International Airport in the early 1990's. Apparently the once-thriving ground-nesting terns could adjust to the regular disturbance of jet landings and take-offs, but couldn't tolerate the non-native predators. A similar threat is faced by least terns on Alameda Naval Air Station, a property soon to be added to the complex of Federal wildlife refuges that ring San Francisco Bay. Farther south, predation problems continue at Salinas National Wildlife Refuge and at adjacent state parks in the Monterey area, where exclosure fencing has been built to protect western snowy plover nests.
Concerns exist in other states, too. In Florida, marsh rabbits in Key West face predation from domestic cats, and several unique species of island mice and woodrats have been driven to near-extinction by cats introduced by people living on coastal barrier islands. A recent Wisconsin study put the annual toll to migratory birds from free-ranging domestic cats in the rural areas of that state at an estimated 39 million birds.
Cats and Wildlife/A Conservation Dilemma makes the point that predation on birds and other wild animals is less a problem of feline behavior -- cats are, after all, simply exhibiting and acting on their innate behavior -- and more a symptom of human influence in modifying the natural environment. As more domesticated animals enter natural areas -- either on their own or through human intervention -- conflicts will inevitably occur. Specifically, the brochure notes:
Single copies of the six-page brochure are also available for a limited time by writing the Office of Public Affairs/Regional Publications Unit, U.S. Fish and Wildlife Service, 911 N.E. 11th Avenue, Portland, Oregon 97232-4181. This publication is not copyrighted and duplication is permitted and encouraged by the authors.