It was almost like a scene out of Halloween movie.
Backyard wildlife enthusiasts in western Washington reported finding six dead bats scattered on their porch and lawn.
Washington Department of Fish and Wildlife (WDFW) biologist Chris Anderson, based in the North Puget Sound region office in Mill Creek, explored the possibilities with the concerned reporting party.
The neighborhood was full of birds, bats, raccoons, squirrels, and cats, Anderson learned. When he first suggested there might be a situation that allowed a house cat – a potentially very effective predator – to take advantage of the local bats, there wasn’t initially much belief.
But when the property owners set up a night watch to learn what was happening, the results were as educational as scary….
They keyed in on a locally-familiar, free-ranging, homeless cat hiding by their flowering yucca plant.
Yuccas flower both day and night and are great nectar sources for butterflies and moths. They hadn’t realized until that night how attractive yucca nectar is to night-flying moths, and they watched many coming in to feed.
And then nature’s food chain displayed itself.
The feeding moths attracted hungry bats, swooping in to grab a meal of moth. The feeding bats, in turn, were killed by the quietly waiting cat.
With two more dead bats left by the cat on their lawn, two things became clear: the cat wasn’t necessarily hunting out of hunger, and for the sake of the neighborhood’s wildlife, it needed to be removed from the area.
The situation was relayed to neighbors, some who may have been feeding the homeless but tame cat, and then it was taken to a shelter for care and adoption by a cat lover who will keep it indoors.
“These folks gave both the bats and the stray cat itself a break,” Anderson said. “It was really the best option. And the situation helped them realize that free-ranging domestic cats are deadly to wildlife.”
Americans’ most popular pet is also one of the most harmful to backyard wildlife.
Our 84 million or so pet cats, plus perhaps at least that many homeless feral cats, kill billions of birds, small mammals and other wildlife each year.
Anderson is a cat owner who believes we can have both in our lives.
“Research shows that spending time with pets and spending time watching wildlife both lower stress levels,” Anderson said. “So why not have both?”
Anderson walks his cat outdoors on a leash with a harness, but otherwise keeps it indoors. “He didn’t like the leash when we first adopted him,” he said, “but he adjusted to it and my two dogs. Now my cat enjoys the outdoors safely, both for him and for wildlife.”
The lives of free-roaming pet cats are often cut short by vehicle collisions, disease, poisoning, parasites, territorial fighting, and predation. According to the Humane Society, indoor cats and those confined or controlled when outdoors can average at least three times the lifespan of free-ranging cats.
Wildlife definitely benefits from keeping cats indoors and under control when outdoors.
Extensive studies of the feeding habits of free-roaming domestic cats have been conducted over the last 55 years throughout the world. These studies show the number and types of animals killed by cats varies greatly, depending on the individual cats, the time of year, and availability of prey. Roughly 60 to 70 percent of the wildlife cats kill are small mammals; 20 to 30 percent are birds; and up to 10 percent are amphibians, reptiles, and insects.
Some free-roaming domestic cats kill more than 100 animals each year. One well-fed cat that roamed a wildlife experiment station was recorded to have killed more than 1,600 animals (mostly small mammals) over 18 months. Rural cats take more prey than suburban or urban cats. Birds that nest or feed on the ground, such as California quail, are the most susceptible to cat predation, as are nestlings and fledglings of many other bird species.
Well-fed cats kill birds and other wildlife because the hunting instinct is independent of the urge to eat. In one study, six cats were presented with a live small rat while eating their preferred food. All six cats stopped eating the food, killed the rat, and then resumed eating the food.
Other studies have shown that bells on collars are not effective in preventing cats from killing birds or other wildlife. Birds do not necessarily associate the sound of a bell with danger, and cats with bells can learn to silently stalk their prey. Even if the bell on the collar rings, it may ring too late, and bells offer no protection for helpless nestlings and fledglings.
Wildlife rehabilitation centers report that most small animals injured by cats die. Cats carry many types of bacteria and viruses in their mouths, some of which can be transmitted to their victims. Even if treatment is administered immediately, only about 20 percent of these patients survive the ordeal. A victim that looks perfectly healthy may die from internal hemorrhaging or injury to vital organs.
Anderson noted that the idea of trapping, spaying/neutering, releasing, and leaving food out for feral cats is misguided.
Cats are solitary animals, but groups of feral cats often form around an artificial feeding source, such as garbage dumps or food put out for them. These populations can grow very quickly, even if most are spayed or neutered — it only takes one intact cat to start multiplying!
These feral cat colonies can have significant impacts on wildlife populations and feeding doesn’t prevent them from following predatory instincts. Feral cat colonies can also cause significant health risks to other cats and humans.
“Cats are good pets but lousy outdoor companions,” Anderson said. “It’s a cat’s nature to stalk prey, even when they’re well fed. We cat owners need to take responsibility for them and keep our wildlife safe.”
For more information see American Bird Conservancy’s “Cats Indoors” campaign at http://www.abcbirds.org/abcprograms/policy/cats/