Denver Cats help rid households of mice, but charming kitties kill more than just rodents. Predation on Colorado's bird populations, and other wildlife, by free-roaming and feral cats is a daily occurrence.
Although there are no laws against cats preying on birds, squirrels, baby rabbits and other small species, Colorado wildlife officials suggests cat owners keep their pets inside to protect vulnerable wildlife.
Outdoor felines are usually active hunters and will occasionally bring home a "gift" for their owners.
"Everyone has had the experience of a cat bringing home a bird," said Dean Riggs, district wildlife manager in Pueblo. "But cats hunting at their own free will is equivalent to allowing hunters to go out without a license and shoot everything they see."
Cat owners need to realize that for every bird their cat drops on the doorstep, there are many more injured and dead that we do not see, he added.
According to the Lindsay Wildlife Museum of Walnut Creek, Calif., cats kill between four and five million birds a day in the United States, or more than a billion birds a year.
Studies show felines are dangerously depleting ground-nesting birds and killing countless numbers of baby songbirds in the spring.
Domestic cats are the most numerous pets (60 million -- 30 percent of households have them). And research shows the problem is not just free roaming "house cats," but also feral cats.
According to the publication Birder's World, there are 60 million wild cats roaming the country. With 120 million cats hunting in rural and urban areas, songbird populations have been seriously affected. Statistics show a decline in the numbers of songbirds such as, tanagers, warblers, vireos and others.
Even well-fed cats are predators, apparently out of instinct. According to Linda Cope of the Wild Forever Foundation in Colorado Springs, wildlife veterinarians in Colorado see thousands of birds each year that are injured by cats.
"Although cats are predators by nature, very rarely do they eat the birds they catch," she said.
Cope says that rehabilitators save the lives of less than half the birds they receive from cat attacks. Birds attacked by cats that do not die immediately may later die from infection.
"The bacteria in a cat's mouth is quite deadly to a tiny bird," Cope explained.
Although predation is natural, domestic cats are not native to the United States, are not wild animals, and are maintained at artificially high numbers by humans who provide food, shelter and veterinarian care.
Riggs recommends that people just keep their cats indoors, particularly during the evening and morning hours when birds are most vulnerable.
"Cats are healthier and live longer if kept indoors, and not given the privilege to hunt," he said.