First posted on 06-08-2012
Non-native species almost always exact a toll on the natives. Large crayfish overpower smaller varieties, Japanese beetles decimate tree leaves, kudzu engulfs about anything that isn’t moving too fast, and both feral and house cats significantly diminish songbird populations.
The Audubon Society says that over 100 million songbird deaths are at the jaws of cats each year in the U.S. The American Bird Conservatory pegs that number closer to 500 million, and the U.S. Fish and Wildlife Service simply says “hundreds of millions” of songbirds die each year from attacks by cats.
Behind that gentle purr emanating from a puff of fur lies a killing machine. That’s not the fault of the cat. They naturally respond to the cries of fledgling birds and pounce on prey as the instinctive hunters they are. But those instincts clearly result in a huge destruction of wildlife when cats are allowed to roam outdoors.
Cats are not native to North America. Like many other non-native species, they were brought here from another location—Europe in this case—as pilgrims and pioneers made their way across the ocean to settle a new country.
Native species develop defenses to predatory native species, but become overwhelmed by the often superior predation strategies of non-natives. Evolving new defenses can take a long time, certainly longer for songbirds than the years that cats have roamed this continent. In the meantime, millions of birds die each year.
This is particularly worrisome as songbirds also get pressured by the loss of suitable habitat as human populations grow and cities sprawl. Birds seem to get squeezed from two ends of the spectrum at once.
Besides many millions of house cats, estimates range as high as 80 million for the number of feral cats prowling U.S. streets, fields and backyards. Many animal shelters across the nation take in feral cats and, rather than choose euthanasia, nurse the critters to health and release them back into the wild where they become more efficient songbird murderers as a result of their stronger state.
Even if you don’t own a cat, that tuft of feathers you discovered in the yard may be the result of a feral cat that scaled the privacy fence and feasted on a young bird. Those are the most vulnerable to attack—the young fledglings that remain grounded for days and squeak incessantly until the parent birds bring food. Unable to fly, they’re sitting fowl to become cat food.
Spring is a particularly bad time for songbirds and a good one for hunting cats. The number of helpless fledglings soars, at least for a while. Some studies say that cats can kill up to 20 fledglings each day. A robin typically hatches 3 to 4 eggs. The odds are not in the birds’ favor.
Hating cats would be a difficult thing to do. Even the more aloof ones often respond when petted. But their human owners need to consider before letting cats outside to wander, and to hunt. On a farm, there may be little choice since cats are efficient when controlling rodent populations. And, keeping cats indoors all the time may not be reasonable, either.
But penning them up inside, at least during spring bird birthing and fall migration periods, would certainly reduce the number of wildlife deaths domestic cats cause. Feral cats, on the other hand, do not help protect grain and hay, nor do they wish to settle down with human companions. Euthanasia seems a far better option than letting them run wild where they can negatively affect native wildlife.
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