Why Feral Eradication Won't Work
The following article is copyrighted by Sarah Hartwell and presented by the Feral Cat Coalition with permission. Sarah has written many articles about feral conditions in the United Kingdom, United States, and Australia. Many of her works were originally intended for audiences outside the U.S., but the information is very good and useful to people from all corners of the globe. One of her original reasons for research and writing was to raise money for feral programs.
In parts of Australia and America there is talk of exterminating stray/feral cats to protect wildlife, a strategy enthusiastically supported by those who view ferals as nuisance animals. However, extermination isn't simple or straightforward and is often counter-productive. No eradication method is 100% effective in eliminating cats from large areas and cats which evade the exterminators breed several times a year depending on climate and available food/shelter, quickly re-colonising the area. Cleared areas have under-utilized food sources which attract new cats from outside. The only way to keep an area cat-free is to remove food sources (edible refuse, prey species, handouts by cat-lovers), something which is often impossible or impractical.
Throughout the world there are conflicting views on feral cats. In some places they are viewed as beneficial animals, controlling vermin. From the days of ancient Egypt ferals have been "employed" to control vermin. Their presence may give pleasure to people who enjoy watching them, although some misguided "carers" disagree with neutering ferals because they enjoy seeing the kittens (90% of which die in their first year). Elsewhere, ferals are considered pests on grounds of hygiene, vectors of disease (rabies, toxoplasmosis), predation upon wildlife or simply because their presence is inconvenient.
FCC Note: The literature indicates that cats are actually not a vector for rabies. They can, however, carry the disease for the very short time it takes them to die from it themselves. Another item of note here is that rabies is transmitted by saliva (bites), not claws (scratches). Feral cats are a very minor player in the rabies chain.
Are Ferals a Nuisance?
In Australia, it is claimed that ferals decimate wildlife although there is a strong counter-argument that cats are scapegoats for direct human activities. Although cats are generally believed to have been introduced by European settlers, aboriginal peoples have claimed that cats were present prior to the settlers' arrival. Factors such as overclearing and overstocking of land, clearing of land for development and the deliberate introduction of other alien species are rarely considered. Studies indicate that the cats prefer to hunt introduced "pest" species (pigeons, rabbits, mice etc) and in Tasmania the feral cat co-exists with the marsupial "native cat."
In America, ferals were blamed for the declining songbird population in San Francisco's Golden Gate Park. A 1992 article in the San Francisco Chronicle blamed the cats, but citizens who fed both cats and birds, some for over 20 years, disagreed since the decline followed a park landscaping programme which had removed undergrowth needed by birds for food and habitat. Predators rarely overbreed to a point where the food supply is too depleted to support their population — the supply of prey limits the number of predators in the area.
Many of the Parks's cats had been neutered and by removing them, Park authorities encouraged other cats to move in and begin their breeding cycle in the vacant ecological niche. Similar situations arose at Riverside Park, Virginia where the cats were perceived as a threat to wildlife and the Gillis W. Long Hansen's Disease Center, Louisiana where they were considered a health hazard. In Louisiana the problem was complicated by the fact that patients enjoyed seeing the cats and ignored regulations forbidding them to feed feral cats around the institution. At Riverside Park, cats were trapped and destroyed during the spring breeding season, despite opposition from welfare groups. Trapped cats included lactating females; dead and dying kittens were subsequently found in the park, yet the trapping programme was supported by the Humane Society of the United States.
In Britain, ferals are viewed as a nuisance by gamekeepers afraid for their pheasant stocks and by some farmers. Some farmers ask rabbit shooters on their land to shoot ferals. One farmer even organised a "feral-shooting party." Pet cats living near such farms have gone missing or returned with shotgun injuries or trailing rabbit snares. Feral colonies may be viewed as a health hazard (faeces, spraying, disease) at hospitals or factories, or as a general nuisance (calling, spraying) in residential areas.
Attempts at Extermination
Southeast of South Africa is the small and inhospitable Marion Island (12 miles by 8 miles). In 1949, a group of scientists left the island, leaving behind 5 unneutered cats. By 1975 there were 2,500 cats on the island preying on ground-nesting seabirds. Deliberate infection with feline enteritis killed around 65% of the cats, but the remainder developed an immunity to the disease. Terrier dogs were used to flush out the remaining cats. Between 1986 and 1989 further surviving cats were exterminated by hunting. Finally poison was used to eliminate the remaining cats. It took 16 years of crude and cruel methods to eradicate 2,500 cats in a small, isolated area, so how can eradication work where cats from outside can recolonise cleared areas?
In an area as large as Australia, eradication is an impossibility. In 1992, at a cattle station in the South Western Australian outback, 175 ferals were shot in a 10 square kilometre area. The army shot 400 more in 3 days, but a few weeks later they returned to shoot another 200. According to reports, cats were pouring into the vacated area. This vacuum effect caused by such culling can result in an area becoming more densely populated with cats, as found in Morialta Reserve, Australia. Even in locations where the vacuum effect is impossible, a single breeding pair is all it takes to replenish the cat population.
In the Essex village of Boreham there are several "problem" feral colonies. Many residents wanted the colonies removed. Despite regular trapping/removal programmes, the village's feral population quickly returned to its previous level as ferals from neighbouring colonies moved into the vacated area and unneutered pets and strays bred. A few residents were maintaining and caring for stable neutered colonies, but wherever the cats were removed completely, new breeding colonies quickly established themselves.
Cat-Kill Methods — Inhumane and Ineffective
Many methods have been proposed for exterminating feral cats. On Marion Island viral agents were only partially effective, yet such a method was recently backed by South Australian MP Peter Lewis as a way of killing off ferals in the same way that myxomatosis was used against rabbits. The introduction of myxomatosis in the United Kingdom caused a temporary drop in rabbit numbers and also killed many pets rabbits. Inevitably, some rabbits survived and with less competition for food they bred quickly, passing their immunity on to their descendants. A similar effect was seen among the Marion Island cats. In addition, a virus cannot distinguish between ferals and pets. Some cats do not develop good immunity after vaccination, some are allergic to vaccines and some cat owners simply cannot afford vaccinations as well as neutering (many rely on subsidised snipping), so many well-loved pets would be killed by viral agents.
Poisoning is sometimes used against feral cats, but is very indiscriminate as the huge death toll among native Australian animals from poison laid during a mouse plague has shown. The cat's sensitive nose might allow it to shun poison bait while beneficial animals such as the hedgehog might consume poisoned cat food. It's also worth considering that attempts to control pigeons through poisoning killed many birds of prey who ate poisoned prey. Creatures which eat carrion might consume the poison second-hand. Though there are restrictions governing the use of poison, these are not always observed. Poison has apparently been used quite recently against ferals at an Essex post office.
Steel-jaw traps are used in some countries, but are both inhumane and indiscriminate as pets and rare/endangered animals also fall victim to traps. This method probably does more harm than the trappers' intended victims. Shooting is possible if carried out by a trained marksman (untrained individuals may injure rather than kill), but it is impossible to distinguish a feral from a wandering pet at a distance (shooting may be the only safe method if the cat is rabid). Another utterly distasteful method is clubbing. I have been told that feral cats and kittens are killed by clubbing on a certain private golf-course in Essex, although hard evidence is impossible to obtain.
This leaves box-trapping and euthanasia; humane but tedious, and consequently costly, if carried out properly. The only people with the patience to continually check traps tend to be cat workers whose love for cats endows them with the devotion to duty needed for such work — and such people are rarely in favour of destroying healthy cats. Lactating cats should be freed for humane reasons (unless the kittens are also collected), domestic pets should also be freed as should wild animals which become trapped (hedgehogs are particularly attracted to cat food and are heavy enough to spring the trap). Less conscientious trappers who regard the cats as a nuisance may simply leave trapped animals (regardless of species) to die of dehydration or starvation to save effort or euthanasia fees. A number of years ago some newspapers reported that cats were being trapped in part of Japan. Anyone finding a trapped cat was forbidden to release it or to provide food or water and it was alleged that many cats were left to die in the traps. Once again the method is not 100% effective as cats too trap-shy to be caught will simply continue breeding.
One aspect of eradication rarely given a second thought by those who want colonies removed, is what happens to the trapped cats. Many members of the public seem to think that the cats are transported to some farmyard paradise and let loose. Some have even asked pest control operatives "how the trapped cats are doing" and are horrified to learn that the cats are not happily living out their days on Old MacDonald's farm, but were destroyed. There is the risk that the method of "en masse euthanasia" used when large numbers of cats are trapped are the least costly, fast-throughput methods, not the most humane ones. Australian cat-workers have told me of the shooting of feral cats and kittens in crush machines at council depots. Even in animal-welfare-conscious Britain some rural people still prefer to drown excess cats by the sackful.
Eradication, by whatever method has been sanctioned, almost always leads to the vacuum effect, small islands excepted. "New" cats flock to the vacated area to exploit whatever food source attracted the original inhabitants or survivors breed and their descendants are more cautious or more disease resistant. "Eradication" is only a temporary fix. What is needed is a humane, long-term approach to feral control.
Cat-Control Methods — Enlightened and Effective
Firstly, why are the ferals being removed? Are they just inconvenient, do they pose a genuine threat to wildlife or are the cats themselves diseased and unhealthy? Extermination is usually attempted for human convenience; rarely is it undertaken because the cats themselves are suffering. Are the instigators of an extermination programme aware of the vacuum effect?
What attracts the cats into the area? On some airbases ferals colonies have been removed by CPL groups, but the presence of edible refuse (and consequently rodents) attracted new cats to the area. Only when refuse was placed in rodent-proof, cat-proof bins did the cats go for good. Elsewhere the cats were being fed by posses of cat-lovers who could not understand why "their" cats were considered a problem by other residents.
Would a smaller, stable and controlled population be acceptable in the area? Quite often those who are opposed to a teeming mass of 30 unneutered scavenging cats displaying all the problems associated with unneutered cats are amenable to a resident colony of 12 neutered cats which are fed in specific areas and which do not spray, fight, caterwaul, midden or breed. Those people who are opposed to seeing scrawny strays (on either aesthetic or welfare grounds) are often pleasantly surprised to find that cats in a neutered colony are healthier and altogether nicer to have around. Such a compromise might be possible if it is explained that the cats are not going off to some rural idyll, but will most likely be put to sleep.
How can a colony be reduced in size? Most colonies will contain cats which are FeLV/FIV positive, ill, injured or suffering from the ravages of age. For these, euthanasia is the kindest option. Feral cats are not co-operative patients and resent being kept captive while they are treated. Some cat sanctuaries have large enclosures with sheds, chalets and enough space for such cats to live semi-free lives, but there are always more cats than there are spaces at such sanctuaries and sanctuaries offering adequately sized enclosures which aren't overcrowded are few and far between. Other cats in the colony may be tame strays which are homeable; there may be tameable kittens or even a local landowner who actually wants to acquire some neutered ferals. The healthiest cats are the ones which should be neutered and returned to site as these have the best long-term chance of a decent life.
In contrast to the problems in San Francisco, Virginia and Louisiana, ferals in Longwood Gardens, Pennsylvania were trapped, neutered and released and provided with litterboxes and shelters. At the same time, efforts were made to preserve or increase bird habitats in the gardens. Despite the presence of the cats, the bird population, including ground-nesting species, has increased. The cats themselves are an added attraction with visitors. Australian studies found that the neutering of several feral colonies led to an overall reduction in cat numbers as the resident, non-breeding populations deterred other cats which would have swarmed into a vacated area. The few cats which did join the managed colonies could be identified, trapped and neutered, or rehomed if tame.
Eradication methods, even if implemented humanely, cannot solve the feral cat problem. Trap-neuter-return methods sometimes seem like a drop in the ocean, but offer a longer-term solution, giving healthy ferals the chance of a decent life and freedom from the otherwise endless cycle of breeding while those which cannot be re-released can at least be given a humane and painless escape from their predicament.
Further Reading
- Feral Cats: Suggestions for Control, UFAW Publications.
- "Practical Guide to Working with Feral Cats," Anne Haughie, FAB Bulletin, Autumn 1991, Vol. 28, No. 2.
- "Resiting Feral Cats," Anne Haughie, FAB Journal, Winter 1992, Vol. 29, No. 4.
Content Copyright 1995 Sarah Hartwell / Feline Advisory Bureau
HTML Copyright 1996 Feral Cat Coalition
[Page updated November 2009]