We've talked in class about the impact of domesticate/companion animals on our environment. One example that affects our local communities is the outdoor cat. Over the years, a number of studies have linked both feral and free-ranging domesticate cats to ecological disruption, including bird predation that in turn impacts the rest of the ecosystem. Here's a recent article that appeared in the "Science" section of The New York Times:
Tweety Was Right: Cats Are a Bird’s No. 1 Enemy
By ELISABETH ROSENTHAL
While public attention has focused on wind turbines as a menace to birds, a new study shows that a far greater threat may be posed by a more familiar antagonist: the pet house cat.
A new study in The Journal of Ornithology on the mortality of baby gray catbirds in the Washington suburbs found that cats were the No. 1 killer in the area, by a large margin.
Nearly 80 percent of the birds were killed by predators, and cats were responsible for 47 percent of those deaths, according to the researchers, from the Smithsonian Institution and Towson University in Maryland. Death rates were particularly high in neighborhoods with large cat populations.
Predation was so serious in some areas that the catbirds could not replace their numbers for the next generation, according to the researchers, who affixed tiny radio transmitters to the birds to follow them. It is the first scientific study to calculate what fraction of bird deaths during the vulnerable fledgling stage can be attributed to cats.
“Cats are way up there in terms of threats to birds — they are a formidable force in driving out native species,” said Peter Marra of the Smithsonian Conservation Biology Institute, one of the authors of the study.
The American Bird Conservancy estimates that up to 500 million birds are killed each year by cats — about half by pets and half by feral felines. “I hope we can now stop minimizing and trivializing the impacts that outdoor cats have on the environment and start addressing the serious problem of cat predation,” said Darin Schroeder, the group’s vice president for conservation advocacy.
By contrast, 440,000 birds are killed by wind turbines each year, according to the United States Fish and Wildlife Service, although that number is expected to exceed one million by 2030 as the number of wind farms grows to meet increased demand.
The American Bird Conservancy generally supports the development of wind energy, but it argues that wind farms should be “bird smart” — for example, positioned so that they do not interfere with major migration paths or disturb breeding grounds, with their power lines buried to prevent collisions.
“I’m excited about wind; we just have to be careful where and how we put the turbines,” said Dr. Marra, who studies threats to birds, including from climate change and habitat loss. He said the leading cause of bird deaths over all, as opposed to the catbird fledglings in the study, remained collisions with buildings, windows and towers, followed by predators.
Yet wind turbines often provoke greater outrage than cats do, said Gavin Shire, vice president of the Bird Conservancy. “The idea of a man-made machine chopping a bird in half creates a visceral reaction,” he said, “while the idea of a predator with its prey in its mouth — well we’ve seen that on the Nature Channel. People’s reaction is that it is normal for cats to kill birds.”
Household cats were introduced in North America by European colonists; they are regarded as an invasive species and have few natural enemies to check their numbers. “They are like gypsy moths and kudzu — they cause major ecological disruption,” Dr. Marra said.
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By ELISABETH ROSENTHAL
While public attention has focused on wind turbines as a menace to birds, a new study shows that a far greater threat may be posed by a more familiar antagonist: the pet house cat.
A new study in The Journal of Ornithology on the mortality of baby gray catbirds in the Washington suburbs found that cats were the No. 1 killer in the area, by a large margin.
Nearly 80 percent of the birds were killed by predators, and cats were responsible for 47 percent of those deaths, according to the researchers, from the Smithsonian Institution and Towson University in Maryland. Death rates were particularly high in neighborhoods with large cat populations.
Predation was so serious in some areas that the catbirds could not replace their numbers for the next generation, according to the researchers, who affixed tiny radio transmitters to the birds to follow them. It is the first scientific study to calculate what fraction of bird deaths during the vulnerable fledgling stage can be attributed to cats.
“Cats are way up there in terms of threats to birds — they are a formidable force in driving out native species,” said Peter Marra of the Smithsonian Conservation Biology Institute, one of the authors of the study.
The American Bird Conservancy estimates that up to 500 million birds are killed each year by cats — about half by pets and half by feral felines. “I hope we can now stop minimizing and trivializing the impacts that outdoor cats have on the environment and start addressing the serious problem of cat predation,” said Darin Schroeder, the group’s vice president for conservation advocacy.
By contrast, 440,000 birds are killed by wind turbines each year, according to the United States Fish and Wildlife Service, although that number is expected to exceed one million by 2030 as the number of wind farms grows to meet increased demand.
The American Bird Conservancy generally supports the development of wind energy, but it argues that wind farms should be “bird smart” — for example, positioned so that they do not interfere with major migration paths or disturb breeding grounds, with their power lines buried to prevent collisions.
“I’m excited about wind; we just have to be careful where and how we put the turbines,” said Dr. Marra, who studies threats to birds, including from climate change and habitat loss. He said the leading cause of bird deaths over all, as opposed to the catbird fledglings in the study, remained collisions with buildings, windows and towers, followed by predators.
Yet wind turbines often provoke greater outrage than cats do, said Gavin Shire, vice president of the Bird Conservancy. “The idea of a man-made machine chopping a bird in half creates a visceral reaction,” he said, “while the idea of a predator with its prey in its mouth — well we’ve seen that on the Nature Channel. People’s reaction is that it is normal for cats to kill birds.”
Household cats were introduced in North America by European colonists; they are regarded as an invasive species and have few natural enemies to check their numbers. “They are like gypsy moths and kudzu — they cause major ecological disruption,” Dr. Marra said.
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The American Bird Conservancy is anti-TNR and pro-euthanasia of feral/free-roaming cats, which doesn't seem to be an ethical solution, especially when we consider that the root of the problem is not cats but humans. At the same time, feral and free-ranging cats continue to be a problem not only for the ecosystem, but also for the cats. The following is a good list of reasons for keeping companion-animal cats indoors:
Why Should You Keep Your Cat Indoors?
Why Should You Keep Your Cat Indoors?
Cats may love to go outside, but for their own good, keep them in. Although cats are smart, alert and adroit, they are no matches for the many perils that await them outside. That's why the average indoor-only cat lives up to three times longer than the cat that goes outside. Consider these threats:
Disease: Feline leukemia and feline immunodeficiency virus are only two of the diseases that are passed from cat to cat and, once contracted, result in the eventual death of the pet. And outside cats are even more likely than dogs to come into contact with rabid wild animals.
Parasites: Outdoor cats suffer from fleas, ticks, ear mites and worms that indoor cats are generally not exposed to.
Poisoning: Poisons can be found in lawn chemicals, bait left out to kill rodents, auto antifreeze and other sources.
Other Animals: Fights with other cats, dogs and wildlife often leave cats maimed or injured. And it's not just tomcats. Female cats also get into fights because the very nature of cats is territorial.
Cruel People: Cats are often the victims of burning, tarring and feathering, and other tortures. Animal dealers may collect outside cats for sale to research facilities. Outside pets are at the mercy of the people they encounter.
Traps: It is estimated that over 100,000 cats are caught in traps each year. Those who aren't killed may suffer for days before being released and often lose limbs fro the injuries.
Traffic: Most outdoor cats die prematurely from auto accidents. It is a myth that cats are "streetwise" about cars. No matter how alert a cat is, it is no match for a fast moving vehicle.
Pet Overpopulation: Unaltered cats allowed to roam and mate at will account for millions of the cats that must be euthanized each year because there aren't enough homes for them. Allowing unaltered animals outside is irresponsible and at the root of the terrible pet overpopulation problem.
Cats can be completely happy inside if you provide them with toys, good care and most importantly, lots of love and attention. If you have a kitten, start it out right by never letting him or her outside. Older cats that are used to the "great outdoors" can make the transition to being indoor cats with time and attention. Spaying and neutering cats will also help you keep them indoors.
For another perspective on the Smithsonian study:
ReplyDeletewww.alleycat.org/NetCommunity/Page.aspx?pid=945