One of the most contentious debates between wildlife enthusiasts and cat owners is the impact of domestic cats on other species, including songbirds, reptiles and small mammals. Cats have a talent for killing small animals. Cat owners who allow their pets outdoors and those people who feed colonies of feral cats play a role in cats' damaging effect on local wildlife. But there are solutions.

For some cat lovers, keeping cats indoors is not an option they'll consider (even though science has proven indoor cats live longer, healthier lives). Such was the case of Nancy Brennan, creator of the Birdsbesafe cat collar.

She says her cat George "was a terror in our Vermont yard and woods. Sometimes, he would catch a bird each day. It was altogether heart-breaking, but George was used to going outdoors at will through his cat door. What to do? We agonized, and tried every so-called solution we could find." (Every solution except the obvious one of keeping him indoors, which of course is the only fail-proof way to stopping a cat from killing wildlife.)

George isn't the only cat with a predilection for killing. A 2013 study published in Nature estimated that "free-ranging domestic cats kill 1.3 to 4.0 billion birds and 6.3 to 22.3 billion mammals annually. Un-owned cats, as opposed to owned pets, cause the majority of this mortality." The researchers also state that "free-ranging cats cause substantially greater wildlife mortality than previously thought and are likely the single greatest source of anthropogenic mortality for US birds and mammals."

Instead of the indoor-only option for George, Brennan created the Birdsbesafe collar as a way to allow George to remain an outdoor cat but to reduce his ability to catch birds.

The colorful collars with reflective trim make the cat more visible to its prey, giving songbirds a better opportunity to spot the cat and escape danger. It is a loop of fabric that fits around a break-away collar, which also helps keep the cat safe if the collar gets snagged on anything. The collars have an extra benefit as well: the reflective trim makes cats more visible to cars at night.

cat collar

Anecdotally, the collar worked, with George only killing a reported two or three birds over the next 18 months. But does the collar really work? On all cats? Two independent studies have taken a closer look at the efficacy of the Birdsbesafe collar and have given it the thumbs-up.

One study by researchers at St. Lawrence University and published in Science Direct did two tests, one on 54 cats in autumn and one on 19 cats in spring. The researchers found that cats wearing the collars killed 3.4 times fewer birds than uncollared cats in autumn, and 19 times fewer birds than uncollared cats in spring.

Another study published in Applied Animal Behavior Science looked at 114 pet cats in Australia over two years and found that among prey with good color vision, captures were reduced by 47 percent (the rainbow collars worked better than the yellow collars for alerting birds). The researchers note, "To date, the [Birdsbesafe collar] is the only predation deterrent that reduces significantly the number of herpetofauna brought home. It is unsuitable where endangered mammalian prey or large invertebrates are vulnerable to predation by pet cats."

While it certainly helps to reduce the number of birds a cat kills, it doesn't eliminate the cat's ability to catch songbirds or birds in general. It also has no clear impact on a cat's ability to catch rodents. In the St. Lawrence University study, the small mammal data wasn't as clear and in the Australian study, "captures of mammals were not reduced significantly."

Though a Birdsbesafe collar on outdoor pet cats may help songbirds to an extent (and reptiles and small mammals to some extent), it doesn't represent a perfect solution to the problem of free-ranging cats feasting on wild fauna, especially since feral cats have a much greater impact on wildlife than pet cats. It is a debate that will continue to rage on between wildlife advocates and feral cat advocates (who could start by putting Birdsbesafe collars on feral cats...).

Still, for those cat owners whose feline family members like to bring home songbirds, the Birdsbesafe collar is proven to be something worth trying.

Is it something you would try on your cat? Let us know in the comments.

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Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.