Feral Cats vs Native Birds

by gloria schole
Spring 2003

What is Feral? :: Feral Cat Problem :: Proposed Solutions :: TNSVR :: Cats Indoors :: Compromise :: Resources

According to many conservation groups, habitat loss from human development is the greatest threat to the existence of native species, ecology and biodiversity. The second greatest threat is the invasion of feral and non-native plants and animals

Unfortunately, resolving the human threat to planet ecology is a complex issue involving politics, finances and cooperation among nations. Although the human impact on ecology is being addressed on many fronts, a complete solution may be decades away. Meanwhile, we cannot ignore the danger of other environmentally invasive flora and fauna, particularly those whose presence is because of human action and not from natural transition.

Habitat loss from human development is the greatest threat to native species, ecology and bio diversity The second greatest threat is the invasion of feral and non-native plants and animals.
What is Feral?

The word feral refers to non-native species that invade an eco-system not adapted to them. Sometimes non-native species are deliberately introduced to an area for a specific purpose. Other times it happens by accident when plants or animals, intended for domestic use, escape or are released into the wild.

Kudzu, for example, is a plant introduced for erosion control. Now the plant itself is spreading out of control. The Gypsy Moth, Nutria, Zebra Mussel, Sea Lamprey, Garlic Mustard, and Purple Loosestrife are among many non-native species that have proliferated and crowded out native species because the normal controls of their native ecosystems are not present in the new areas. As a result, they have caused considerable economic and ecological damage.

Plant and animal members of an ecosystem community normally adapt to a process of checks and balances as they evolve to form a relationship with one another over time. When non-native species from other ecosystems invade, this balance is disrupted and future existence of the plants and animals in that ecosystem is placed in jeopardy.

However, The Environmental Protection Agency writes: "the effects of most non-native animals pale in comparison to the damage done by domestic and feral (free-ranging and wild) cats. Our domestic and wild felines are widely recognized as the greatest threat to birds of any non-native predator. There are probably more than 100 million domestic and feral cats nationwide. Clawed or declawed, well-fed or hungry, bell or no bell, all cats that spend time outside will hunt and kill birds, as well as other wildlife."

Feral Cats

Feral cats are the wild offspring of domestic cats, which originate from Africa. The feral cat population results primarily from the failure of pet owners to spay and neuter their animals. Owner abandonment is another source of feral cats.

Pamela Hatley, a law student at University of Florida's College of Law, summarized the results of a UFL study of the feral cat impact on the feral cat on the hunt environment: "They impact native wildlife in three primary ways: predation, competition, and disease." Hatley goes on to say: "Cats are non-indigenous predators that compete in the wild with native predators like owls, hawks, fox, because cats, being subsidized by humans, outnumber these native predators and prey on the same small mammals and birds. Thus, cats reduce the prey base for native predators, making it difficult for native predators to feed themselves and their young. In addition, these cats spread diseases - rabies in particular - that can kill wildlife. The Centers for Disease Control and Prevention reports that rabies is more than twice as common in cats as it is in dogs or cattle, and cats have the highest incidence of rabies among domestic species."

Tri-State Bird Rescue & Research Inc. concurs: "According to a study in Illinois, cats are killing 5.5 million rodents and 2.5 billion other vertebrates from a 26,000 square mile area. This depletes the prey which are necessary to sustain wintering raptors and other native predators. Data taken from wildlife rehabilitation centers around the US agree with this conclusion."

The University of Florida's is not the only study to find that feral and free-roaming cats have had a devastating effect on native wildlife. Researchers at the University of Wisconsin published the findings of their study Cats and Wildlife: A Conservation Dilemma by J. S. Coleman, S. A. Temple, and S. R. Craven. They found that in Wisconsin alone, cats kill an estimated 39 million birds per year. They wrote: "worldwide, cats may have been involved in the extinction of more bird species than any other cause, except habitat destruction."

The American Zoo and Aquarium Association compiled on their website reports that attribute to free-roaming cats:

Dick Peterson, a bluebird expert and designer of the Peterson bluebird-house pattern has specific concerns about bluebirds: "A cat is about the worst mammal there is on the bluebird trail," Peterson says. Particularly lethal, Peterson explains, are the cat's curved claws, which it uses to reach into the bird house and hook fledglings and nesting adults.

The Minnesota Department of Natural Resources Joan Galli, a DNR non game wildlife specialist explains: "Birds are having a hard enough time these days from habitat loss. As we try to save their habitat, it only makes sense to make sure that birds aren't being killed by our pets."

The Ohio Wildlife Rehabilitation Association offers compelling evidence of the damage caused by free-roaming cats: "cat attack cases and animals orphaned by cats is the single largest reason for admission into many wildlife centers, a larger number than car and window collisions, pesticides, tree felling, and other reasons for injuries and death. The prognosis for recovery of those animals attacked by cats is small---less than 10-20% survive a cat attack! Massive internal hemorrhaging and soft tissue damage from crushing result even when the external damage seems minor. Even small puncture wounds can be fatal, as there are over 60 types of bacteria known to exist in a cat's saliva."

A revealing article by Pat Roberto on the California Department of Fish and Game website begins: " When she lived in Forestville, a small town in Sonoma County, Marilyn Davis was known as a friend to cats. She took in strays at the house she and her husband had built by a creek and in time there were twelve. The Davises and the cats lived happily enough until Marilyn saw a troubling pattern: rabbits, quail, varied thrushes, even snakes and frogs were being dragged over her threshold from the creekside. Because she was also a friend of wildlife, Davis reluctantly confined the most active hunters indoors, but the other cats only seemed to take up the slack. More and more wildlife arrived DOA on her doorstep. More and more cats were brought inside for good until only a few old fat ones were left lolling around on the deck. Whatever flew over their heads, though, they swatted and swallowed, almost in one motion. Finally she faced the truth: "This is their nature, every one of them. They're hunters." "

Such evidence is repeated throughout the United States and in other countries on numerous websites belonging to concerned individuals, wildlife organizations, rescue and rehabilitation organizations, schools of education, parks and recreation departments and state and federal offices.

Alley Cat Allies and The Feral Cat Coalition dispute the findings of cats as hunters. They maintain that cats are opportunistic feeders that prefer to hang around garbage bins and scavenge. Thus, they are of little threat to native wildlife. The majority of documentation they offer to support this premise is from the 1940's and 50's. A later reference is from C. J. Mead, 1982: "The birds in suburban and rural parts of Britain have coexisted with cats for hundreds of generations, and they may now be under less pressure from cats than they were in the past from the assorted natural predators. Any bird populations on the continents that could not withstand these levels of predation from cats and other predators would have disappeared long ago."

These references, 20 to 60 years past, do not account for the fact that birds were once more abundant than they are now and there also were not so many cats. We are dealing with circumstances as they exist today. The cumulative message of current documentation is both overwhelming and convincing: Feral and free-roaming cats are definitely responsible for killing millions of small animals and birds every year.

So, what can we do about it?

Proposed Solutions

Of course, if cat owners would take responsibility for their pet cats, there would be no problem of free-roaming cats and then there would be no ferals. By responsibility I mean that owners insure every pet cat is spayed or neutered so they cannot reproduce. I also mean that when pet owners, are no longer able to keep their cats, they find new homes for them. Finally, I mean that cat owners keep their cats indoors so they cannot kill birds and other wildlife. Educating cat owners to this ideal should be a priority for all of us who care about cats and about birds.

Meanwhile, we must address the problems of the present.

The traditional approach of dealing with stray cats and kittens is to either shoot them or trap them and bring them to the pound or local animal shelter. Some former pets will get adopted and some will find their owners but the vast majority of such cats are euthanized.

Many shelter personnel involved with euthanizing the huge numbers of unwanted pets become sickened with their jobs. Some can manage the emotional issues longer than others and some 'burn out' rapidly. They look at these animals and see them as individuals with a desire to live. They recognize that cat overpopulation results from poor human management but the animals are unfairly being punished because of it. Shelter workers often adopt as many as they can afford to keep, but this effort has little effect on the sheer numbers of unwanted pets.

In repudiation of euthanization, some cat lovers have developed a plan that they hope is the answer to the exploding stray cat population. This program involves Trapping, Spaying, Neutering, Vaccinating and Releasing the cat back into nature. There, the cats will form colonies that will be supplied with food by human volunteers. The theory behind TSNVR programs is that sterilized cats cannot reproduce so eventually the colonies will die out with age. Meanwhile, their presence in an area prevents the influx of other feral cats. Eventually, with this program in place, all feral cat numbers will decline.

Another plan, initiated by the American Bird Conservancy (ABC), states from their website: "Cats Indoors! The Campaign for Safer Birds and Cats to end the unnecessary suffering and death of birds and other wildlife caused by free-roaming domestic cats. Cats Indoors! seeks to educate cat owners, decision makers and the general public that free-roaming cats pose a significant risk to birds and other wildlife, suffer themselves, and pose a threat to human health."

"Cats Indoors! encourages cat owners to keep their cats indoors and advocates laws, regulations, and policies to protect cats and birds, including the humane removal of free-roaming cats from areas important to wildlife. The campaign promotes grassroots efforts to address the issue at state and local levels."

Let's take a closer look at each of these programs.

TNSVR

Trap-Neuter/Spay-Vaccinate-Release has become popular across the nation, especially in urban areas and on college campuses. According to Alley Cat Allies, Trap-Neuter-Return (TNR) is a full management plan in which stray and feral cats already living outdoors in cities, towns, and rural areas are humanely trapped, evaluated (for health and adoptability), vaccinated, and sterilized by veterinarians. Kittens and tame cats are adopted into good homes. Healthy adult cats too wild to be adopted are returned to their familiar habitat under the lifelong care of volunteers.

Texas A&M University College of Veterinary Medicine developed a campus program in August 1998 to Trap, Test, Vaccinate, Alter and Release (TTVAR) based on the one being used by Stanford University. It provided a unique opportunity for veterinary students to study the dynamics of cat colony members and the effect of the management program. The results of this study suggest that programs like theirs, Aggie Feral Cat Alliance of Texas (AFCAT, a group of volunteer faculty, staff and students) could be integrated into veterinary curriculums to educate students on issues involving feral cats and the need and methods for management of these populations.

The Stanford University program was established In 1989 after University officials planned to trap and kill the 500 campus strays. Because of this, Stanford Cat Network was formed to develop a TTVAR progam. Stanford cats now have a declining population. Over 60 kittens were caught, socialized and adopted during the first season. By 1994, only four kittens were found on campus. The campus population is now estimated at approximately 300 cats. Stanford's current cat population is healthy and well-cared for, and its maintenance involves students, staff, and faculty.

Dr. Margaret Slater, a participant of TNR program on the Texas A&M campus, gave presentations on TNR program to the American Veterinary Medical Association July 15, 2002 in Nashville. She described their program and other successful programs. One is conducted by San Francisco Society for the Prevention of Cruelty to Animals, which sterilizes cats for free and pays people $5 to bring in cats to be neutered. They also provide adoption and education programs. Another is the Merrimack River Feline Rescue Society in Newburyport, Mass., which, has reduced its feral cat population from about 200 to roughly 20 animals over a period of 10 years.

Some TNR programs are well-managed, successful, and the cats in the programs are healthy. Such successes, however, are not always the case. An article published in Shelter Sense Vol. 15, No. 5, pages 3-6. 1992, a publication of The Humane Society of the United States, cites several instances to the contrary:

The Universities Federation of Animal Welfare (UFAW), one of the first groups to develop a TNR program, reports long term results of different colonies in England.

  1. Nine of the original 19 cats of one colony either disappeared or were killed or euthanized because of illness, while 17 new cats entered the territory. This colony grew by eight cats despite the deaths of almost half the original colony.
  2. In another colony, the number of feral cats rose from 70-80 to 100 in one year, even though the number of feeders dropped to only one person. During the six and one-half years that this colony was watched, 40 kittens were "homed" and 200 cats neutered. Reports on other colonies tell the same story: large numbers of original members vanish or die and new cats come in on their own or are dumped there by people.

Dr. Carol Haspel, associate professor at LaGuardia Community College in New York, who studied urban feral cats for years reports that cats occupying a certain area do not keep others out, particularly if there is a feeder.

Ellen Kowalski, a cat rescuer in Baltimore, Maryland, says that free-roaming cats are used for target practice by kids with BB guns, firearms, and even bows and arrows. Although the cats in the area are well fed, they have eye infections, abscesses, sores, and deformed limbs.

Surprisingly, Ingrid Newkirk, national director for People for the Ethical Treatment of Animals (PeTA), does not support TNR programs despite the fact that she has been reported saying she would like to see animals living free and separate from humans, "admired from afar." In the case of free-roaming cats, however, she asserts that TNR programs would only be acceptable if they were:

  1. Isolated from roads, people, and other animals who could harm them
  2. Constantly attended to by people who not only feed them but care for their medical needs
  3. Lodged in an area where the weather is constantly temperate.

Newkirk believes that part of the reason why some are so strongly in favor of TNR is because they don't see what eventually happens to the cats but Animal Control Officers and Shelter Workers do. Cats are hit by cars, attacked by dogs and people, are poisoned and suffer a variety of health problems that can't be treated once cats become trap-wise.

Finally, TNR programs do not address the problem of declining wildlife due to cat kills. Feeding cats keeps them strong and better able to hunt than native predators, which become weakened during time of environmental stress.

An article The Rights (and Wrongs) of Cats by Gordy Slack numerates several instances where cat colonies maintained by humans are responsible for wiping out or changing the wildlife profile of the area they inhabit:

Luis Baptista of the California Academy of Sciences, is one of the world's foremost ornithologists. He points to one of the cat feeding stations of Strawberry Hill park. "When I first came here in the 1960s, the rabbits and the quail could be seen on any lawn. White-crowned sparrows were so thick on Strawberry Hill I had trouble isolating the voice of any one of them with my parabola reflector (microphone). Now the ground birds and rabbits are just about gone. I haven't seen a cottontail for years here, and there is only one pair of quail left, inside the arboretum."

Marilyn Davis, a cat rescuer who we met earlier in this article. is co-founder of the Bodega Bay-based Native Species Network, which tracks the feral cat protection movement nationwide. Cities, counties, and park districts all over the country are shifting their land management priorities to accommodate cat feeding. Davis and others believe this is misguided affection, and a catastrophe for native wildlife.

Davis agrees with the view of the Humane Society of the United States, which states: "neuter and release programs amount to nothing more than subsidized abandonment." She adds: "Protecting the wildlife under our stewardship is a public responsibility. Protecting abandoned house cats in the wild is not,"

Douglas Bell, a California Academy of Sciences ornithologist participating in a long-term study of white-crowned sparrow dialects in Golden Gate Park, says cats have had a devastating impact on the park's songbird population. Particularly vulnerable are those that nest near the ground like white-crowns, song sparrows, juncos, and quail. Cats can easily grab a female on her nest.

Cole Hawkins, a Texas A&M researcher studied the difference in rodent and bird populations between areas occupied by and free of cats in the East Bay Regional Parks. He noted that there were significantly more birds in the no-cat areas. He said "I never saw any California quail in the cat area. There were lots in the no-cat area. Same with thrashers. Same with juncos."

Daniel Evans, at the Point Reyes Bird Observatory, states: "the main problem is that we are losing wildlife, and cats are a major cause. People have to decide if they want to go to the park to see wildlife or to see cats."

Something else to consider is this: The Migratory Bird Treaty Act protects native birds from being killed or kept by people. In some states, people are held liable for the cats they feed, in effect becoming their owners. Allowing these cats to hunt freely may place such people in violation of this Act.

During a series of sessions titled "Feral and free-roaming cats: the flip side of the coin," July 14 at the AVMA Annual Convention, Dr. David Jessup, a senior wildlife veterinarian for the state of California, made the point that there may be legal and ethical problems for veterinarians who participate in TNR programs. Dr. Jessup said many of the programs do not follow the AVMA guidelines. For example, some TNR groups keep colonies in public areas or areas designated as wildlife sanctuaries, which may be illegal. Also, by treating a cat and re-releasing it, a veterinarian may be violating anti-abandonment laws.

Cats Indoors

Linda Winter is the director and primary contact of the American Bird Conservancy's Cats Indoors campaign. ABC is providing a fact-filled brochure explaining why it is safer for both cats and birds if cats are prevented from roaming outdoors. http://www.abcbirds.org/cats/brochure/brochure.htm

What organizations such as Alley Cat Allies and other sponsors of TNR programs find alarming about the Cats Indoors program is that it provides no life-saving solution for feral cats. The program also seeks to pass laws against feeding and maintaining ferals.

Essentially, Cats Indoors and TNR groups hold opposing views.

Compromise

One and all we need to be realistic and honest about the problems to wildlife posed by feral and free-roaming cats. Arguing that humans are also responsible for the decline of wildlife does not diminish the fact that free-roaming cats create a problem that requires resolution

We also need to be sensitive to the feelings and opinions of those whose priorities are different from our own. How can we expect cat lovers to care about our concern for birds if we don't respect their desire to protect cats? How can we expect bird lovers to care about our love of cats if we don't respect their desire to protect birds?

The solution doesn't have to be 'either/or'. Cats Indoors is an excellent program that protects birds, pet cats and people. Following its guidelines will help to prevent cat overpopulation and the unwelcome euthanization of so many cats in shelters.

TNR for ferals can be a valid option depending on where it is conducted. It is not appropriate everywhere, but it is more appropriate in urban areas away from parks where birds do not nest. However, the health and welfare of these cats is still an issue.

Another exception to free-roaming cats might possibly be those used specifically around farm buildings for rodent control. These cats should, of course, be 'fixed' so they will not reproduce and will also be less likely to roam. In addition they should be fed and have their health needs met.

Without a doubt, free-roaming cats do not belong anywhere near parks, wildlife sanctuaries, or places where birds nest. Laurella Desborough suggested an option that is barely mentioned in passing on a few websites. The concept involves a cat containment facility for
feral cats. Desborough says: "I have seen one cat containment facility for ferals and it was excellent. The trapped feral cats are quarantined, vetted and then released into a large and well planned indoor/outdoor facility from which they cannot escape. This makes better sense than allowing cats to destroy wildlife which belongs to ALL of us!"

With such a program not only would birds be protected, but the cats themselves would be assured of better management. They would not be run over, shot, poisoned, or attacked by dogs. If they became ill, they could be more easily caught for treatment.

The logistics of space and finances would be an issue but surely those who are passionate about cats would be willing to donate money and volunteer their time to support such a project. To protect wildlife, why couldn't city managers be convinced to set aside an area in each park, sanctuary, and college campus for an enclosure to contain feral cats? Volunteers could erect the facility and more volunteers would be responsible for feeding, much as they do now. It would be a win / win situation for all involved: birds, cats and the people who love both.

Think about it.

Online Resources

Stating the Problems

http://www.nativehabitats.org/cats.htm
http://floridaconservation.org/whatsnew/03/frdcfacts-st.html
http://www.napa.ufl.edu/2003news/feralcat.htm
http://www.enviroliteracy.org/article.php/40.htm
http://www.eco-pros.com/invasive_non-native_species.htm
http://www.worldwatch.org/press/news/1998/10/10/
http://fwie.fw.vt.edu/rhgiles/speciesssm/fcats.htm
http://www.epa.gov/owow/invasive_species/intro.html
http://www.epa.gov/owow/birds/basics.html
http://deal.unl.edu/icwdm/handbook/handbook/allPDF/ca_c45.pdf
http://www.dnr.state.mn.us/fwt/back_issues/december98/cats.html
http://www.aza.org/
http://www.tristatebird.org/cats.htm
http://www.owra.org/cateffect.htm
http://www.wisc.edu/wildlife/e-pubs.html
www.dfg.ca.gov/hcpb/species/nuis_exo/dom_cat/cats_wildlife.shtml
http://www.calacademy.org/calwild/sum98/habitats.htm
http://www.austinferalcats.org/birds.htm

Proposing Solutions

http://www.abcbirds.org/cats/catsindoors.htm
http://www.alleycat.org/index.html
report that tnsvr is effective at reducing populations
http://www.alleycat.org/pdf/buildingthebody.pdf
http://www.feralcat.com/acafcmc.html
http://www.avma.org/onlnews/javma/sep02/020915j.asp
http://www.austinferalcats.org/birds.htm
http://www.feralcat.com/acafcmc.html
http://www.cvm.tamu.edu/afcat/manageprog.htm
http://www.dfg.ca.gov/hcpb/species/nuis_exo/dom_cat/euthanize.shtml
http://catnet.stanford.edu/resources.html
Audubon Society position on feral cats
http://www.audubon.org/local/cn/98march/nasr.html
Humane Society of the United States position on free-roaming cats
http://files.hsus.org/web-files/PDF/PUBS_Slater3.pdf
Community Approaches to Feral Cats
http://www.hsus.org/ace/14631
http://www.abcbirds.org/cats/brochure/brochure.htm