Westchester and Putnam
Songbirds and Free-Roaming Cats

Cats, Cats, Cats

Americans love cats. In fact, cats have become the most popular pet in the United States. 30% of households include cats with an average of 2.1 cats per household. Sadly, many families have not fully accepted their responsibility to their pets. Their negligence has contributed to a large pet overpopulation problem in the U.S. 8-10 million adoptable pets enter U.S. shelters each year and 4-5 million are euthanized annually because there are simply not enough homes or room at shelters for them all. The overpopulation/homeless pet crisis has also led some environmental and wildlife groups to blame cats and especially feral cats for the decline in bird populations

Singling out feral cats to blame for the disappearance of birds and other wildlife becomes problematic when one takes into account that cats elude simple categorizations. Free-roaming cats are often referred to as either stray or feral, but these terms do not reflect the many types of outdoor cats. Any cat that is not confined to a house or enclosure is "free roaming." As stated in the Humane Society of the United States "Statement on Free-Roaming Cats", free-roaming cats can be:

owned cats who are allowed to roam;
owned cats who have become lost;
previously owned cats who have been abandoned and no longer have a home;
quasi-owned cats who roam freely and are fed by several residents in an area but are "owned" by none of them (in the U.S.A. 7-22% of households feed stray cats);
so called working cats who serve as "mousers";
and feral cats who are lost or abandoned domestic cats who have reverted to a wild state or are cats who have had little or no human contact born to a stray or feral mother. Many subsist in colonies of homeless cats living on the fringes of human existence.

Because individual cats exhibit varying degrees of sociability, even an animal care and control professional may not immediately be able to tell the difference between a feral cat and a frightened indoor-only cat who has escaped and become lost. Although free-roaming cats generally cause whatever cat-related problems exist in a given area, feral cats, specifically, are usually blamed for such problems.

Lack of Evidence

Two studies most often quoted to support holding feral cats responsible for the decline in songbirds are the Churcher/Lawton study and "The Wisconsin Study" by John Coleman and Stanley Temple. Both studies are severely flawed in their methodology.

Peter Churcher and John Lawton looked at what kind of prey cats were bringing home in an English village By taking a guess as to how many cats were in Great Britain, Churcher concluded with an astronomical number of killed birds. However, the Churcher/Lawton study is missing vital information. Answers to such fundamental questions as, "How did the birds die?" and "Did the cats kill them?" go unanswered in this study. These and other questions need answers before any of the estimated figures from this study can be relied upon to gauge the impact of cats on Great Britain's birds.

Both studies have been criticized for basing their estimates on very limited data and in the case of the "Wisconsin Study" derived from unpublished data. The "Wisconsin Study" estimates are presented as legitimate research by groups seeking to use them to advance their agenda, despite the fact that data from the relevant study was never published and therefore has not been subject to the peer review process ("How Many Birds Do Cats Kill," Wildlife Control Technology. Jul-Aug 1995: 44). When interviewed on the subject, John Coleman states, "The media has had a field day with this since we started. Those figures were from our proposal. They aren't actual data; that was just our projection to show how bad it might be." Both Dr. Temple in Wisconsin and Peter Churcher in England have expressed dismay at how their projections have been used.

The following excerpt from Gary J. Patronek's, VMD, Ph.D. Tufts University, "Letter to Editor," Journal of the American Veterinary Medical Association, Vol. 209, No. 10, November 15, 1996 speaks to the "science" of the claims made by those who charge feral cat predation for declining bird populations, "Whittling down guesses or extrapolations from limited observations by a factor of 10 or even 100 does not make the estimates any more credible, and the fact that they are the best available data is not sufficient to justify their use…If asking for reasonable data to support the general assertion that wildlife mortality across the United States attributable to cat predation is unacceptable high can be construed as 'attempting to minimize the impact,' then I am guilty as charged. What I find inconsistent in an otherwise scientific debate about biodiversity is how indictment of cats has been pursued almost in spite of the evidence."

More Studies

There is a large body of scientific literature that contradicts the conclusions of the studies of Churcher/Lawton and Coleman/Temple. Over 60 studies on feral cats have been written from different continents throughout the world--all showing three important points:

Cats are opportunistic feeders, eating what is most easily available. Feral cats are scavengers, and many rely on garbage and handouts from people. When the stomach contents of feral cats are examined, invariably the main diet is found to be human refuse, followed by rodents, and to a small extent, birds. Urban cats are connoisseurs of restaurant and other human food. It is cat's scavenging ability that allows them to survive as feral-living animals and live with us eating food off a saucer.
Cats are rodent specialists. Birds make up a small percentage of their diet when they rely solely on hunting for food.
Cats may prey on a population without destroying it. If this were not so, we would no longer have mice around.

Biologist Roger Tabor found that cats have low success as bird hunters and that the bulk of their diet is garbage, plants, insects, and other scavenger material. In short, cats are not impacting bird populations on the continents (The Wild Life of the Domestic Cat, London: Arrow Books, 1983).

Coman & Brunner concluded that "The common belief that feral cats are serious predators of birds is apparently without basis." (Coman BJ, Brunner H. Food habits of the feral house cat in Victoria. J Wildl Mgmt 1972;36:848-853)

Many international biologists agree that only on small islands do cats pose a severe threat to the wildlife populations. They agree with biologist C.J. Mead that "any bird populations on the continents that could not withstand these levels of predation from cats and other predators would have disappeared long ago."

The True Reasons for Declining Bird Populations

A 1994 WorldWatch Institute study showed that of the world's 9,000 bird species, 5,000 are in decline, while another 1,600 are threatened or nearly threatened with extinction. Some populations have fallen by 75% as result of four primary factors: habitat loss, over trapping, drought, and pesticides. Cats are noticeably absent as factors.

As development continues, available habitat for wildlife is carved up into smaller and smaller pieces. Habitat fragmentation and marginalization cause wildlife populations to become genetically separated, and if a particular population is not large enough, remnant populations are subject to genetic inbreeding. As a result, as habitat declines, so does diversity and heterogeneity, resulting in high extinction rates.

Pesticides are also recognized as a major cause in bird decline--particularly the effect of toxic lawn care products in the decline of the songbird. Insecticides, herbicides, fungicides, and rodenticides are routinely used throughout Westchester and Putnam Counties although Westchester is eliminating pesticide use on County property under the "Phase-Out of Pesticides on County Property" initiative. Poisoning as a result of the everyday use of pesticides has become so widespread that biologists term the phenomenon "lawn care syndrome." Other practices such as removal of low-growing shrubbery and tree trimming also impact birds and other wildlife.

Man Made Problems: Man Made Solutions

The ever increasing population of homeless/feral cats and the decline of songbirds both have their root cause in the activity of humans; both are "people problems." Our pets are regarded by many today as disposable commodities in our throwaway society. Too many individuals in America simply do not take responsibility for their pets and do not make the lifetime commitment having a pet demands. Countless irresponsible pet owners abandon their cats and doom them to a life on the streets every day. Feral/homeless cats have become the scapegoats while the real culprit, Homo sapiens, goes free to continue the destruction of the environment. Urban sprawl, shopping malls, road building, golf courses, pesticides in water and air, deforestation--these are the causes of songbird decline and these are the activities that must be curtailed or corrected if wildlife is to prosper once again.

Wildlife and environmental groups and feral cat advocates share one goal: to reduce the number of feral cats in the environment in the long term. The good news is that there is an effective and humane solution to the problem of feral/homeless cat overpopulation. Trap-Neuter-Return is a comprehensive ongoing program in which stray and feral cats already living outdoors in cities, towns, and rural areas are humanely trapped, then evaluated, vaccinated, and sterilized by veterinarians. Kittens and tame (stray) cats are adopted into good homes. Healthy adult cats too wild (feral) to be adopted are returned to their familiar habitat under the care of volunteers. Cats that are ill or injured beyond recovery are not returned to the environment.

Trap-Neuter-Return (TNR) has been used successfully in large and small jurisdictions in every region of the U.S. and is the only method proven to be effective in both the short and long terms in reducing the feral cat populations. The body of scientific evidence that TRN works will be the subject of next Animal-Link.org article on feral/homeless cats.