Rainbow cat collars could save lizards and birds

This article is available in Spanish through a partnership with the Institute of Ecology at the National Autonomous University of Mexico. Read in Spanish >>

Whether you’re a cat person or a dog person (disclosure: this writer is a dog person), we can all probably agree that pet cats can unleash a tremendous amount of destruction on wildlife if they’re allowed outside. According to one study conducted in Great Britain, domestic cats brought up 92 million individual prey items over five months, an estimate that doesn’t include any prey items left out or entirely consumed before returning home. In an average year in the US, cats wipe out around 684 million birds and 1.2 billion mammals. Some owners try to limit the damage their cats do on their local ecosystems, and one popular technique involves using a brightly colored fabric collar with a reflective strip to serve as a warning sign for the cats’ prey.

The idea is that bright colors give animals with good color vision, like birds, a leg up in noticing a stalking predator, allowing them the chance to escape with their lives. Obviously, the best strategy to enjoy a pet cat without inflicting damage elsewhere would be to keep a cat inside at all times. But in places like Australia, the UK, the US, and New Zealand, many owners neither confine their cats to the indoors nor even to their own properties. An intermediate solution is called for, and that’s where devices like the Birdsbesafe cat collar (BBS) come in.

The Vermont-based company claims that their product helps to reduce the number of songbirds killed by cats in North America. They don’t make claims for critters other than songbirds, nor for songbirds outside of North America. Still, since predation by cats happens all over the world, a group of researchers at Australia’s Murdoch University wanted to see whether the BBS could be effective there, and for which taxa.

They expected it would help birds; but amphibians and reptiles also have good color vision and could also be served by the BBS. Most small mammals (not including marsupials and primates) tend to have poor color vision, so they wouldn’t be expected to benefit from the BBS. And perhaps that’s a feature rather than a bug, since cats are often used as de facto control agents against pests like rats and mice.

For two 5-month periods, the researchers, led by graduate student Catherine M. Hall, took to the suburban towns of Perth, Australia, to field test the BBS. The brightly colored cloth fits over a standard cat collar and looks something like a clown collar. Over the two periods, 100 cat-owning households participated. Each cat’s prey count was tallied was counted for six weeks: three while wearing a collar, and three without.

The majority of the reptiles, amphibians, and birds brought in by the cats were native, while most of the mammals were invasive – primarily black rats and house mice – though over the course of the study, cats also brought home 14 southern brown bandicoots, a species of conservation concern.

Among prey with color vision – birds, reptiles, and amphibians – the rainbow colored collar did result in a statistically significant decrease in prey animals brought home by cats, while the red and yellow ones did not. And that result was driven more by the herpetofauna (reptiles and amphibians) than the birds, despite the birds being at the center of the product’s marketing efforts.

Folks might quibble over just how much damage cats truly inflict on wildlife populations, and the truth is that it varies according to location and prey species. In some places, pet cats might hunt common species, even invasive ones which themselves damage an ecosystem. But in other places, cats are responsible for local extirpations of native species and can do serious damage to populations of threatened or endangered ones. Even where actual predation is low, the very threat of predation by cats can lead bird populations to suffer – either through reduced provision to offspring, or because nestling alarm calls attract additional predators, like corvids. The fact is that cats, both feral and owned, cause lots of other animals to lose their lives.

This particular device – at least the rainbow pattern – appears useful for owners who wish to curtail their cats’ successful birds and herptile hunts, while allowing them to continue going after small mammals. Indeed, those same native birds, reptiles, and amphibians could benefit from having fewer rodents around.

Still, it’s not enough for the collars to work. Cat owners also have to believe that they work if they’re to purchase them and dress their cats in the ridiculous-looking fabric getups. At the end of the study, most of the owners (77%) said they had plans to continue using the BBS. Several even felt that the collars also helped to protect the cats themselves, since the bright colors and reflective strips could help cars avoid running them over.

“Concerned owners who do not wish to confine their cats may consider a collar-worn predation deterrent instead,” conclude the researchers. It’s not a perfect solution, but in some places, it may be enough to help struggling native birds, reptiles, and amphibians. – Jason G. Goldman | 09 December 2015

Source: Hall, C. M., Fontaine, J. B., Bryant, K. A., & Calver, M. C. (2015). Assessing the effectiveness of the Birdsbesafe® anti-predation collar cover in reducing predation on wildlife by pet cats in Western Australia. Applied Animal Behaviour Science 173, 40-51. DOI: 10.1016/j.applanim.2015.01.004.

Header image: shutterstock.com



  • Grant Sizemore December 9, 2015 at 9:32 am

    The conservation impacts of outdoor cats are truly vast and challenging, and I appreciate the interest in identifying effective techniques to reduce direct and indirect cat-caused mortality.

    However, a few points of clarification are warrented.

    1. Outdoor cats are estimated to kill approximately 2.4 billion birds and 12.3 billion mammals in the United States every year (Loss et al. 2013). This is considerably more than the 684 million birds and 1.2 billion mammals cited.

    2. Although the BirdsBeSafe collar is an interesting product, we must be careful to recognize its limitations and carefully evaluate Hall et al. (2015) and Willson et al. (2015). As the article stated, only one design indicated a reduction in cat kills, and the effectiveness is likely to vary by taxa. However, we must also realize that effectiveness will vary by other factors, such as time of day or age of prey. A bird at night will be unlikely to see the collar, just as a chick in the nest is unlikely to either see the collar or be able to escape.

    3. Owners, unfortunately, seemed largely unwilling to maintain the collar on their cats in the Willson et al. (2015) study. Only 22% continued to use the collar after the trial. It should be noted that the Hall et al. (2015) study indicated that 77% of owners “plan to continue using” the collar. How this will play out in actual behaviors and the cause for the discrepancy between the two studies is a matter of future research.

    Regardless of these clarifications, we can all agree that the impacts of cats on wildlife must be reduced and, ideally, eliminated. Of course, we should also seek to eliminate the wildlife and human health risks associated with diseases of roaming cats (e.g., toxoplasmosis). Unfortunately, no collar can yet address those concerns.


  • Nancy Brennan December 10, 2015 at 7:19 am

    My name is Nancy Brennan, and I invented the Birdsbesafe® cat collar cover, which I now market in order to help save birds from outdoor pet cats. I really appreciate the efforts of the American Bird Conservancy’s many programs, including the Cats Indoors program, which Grant Sizemore does run. I have a few clarifications on our product.

    Songbirds, known also as passerines, have specialized color vision ability, due to a fourth cone (you have three) that is particularly good at seeing bright colors such as those we use in our product–and those that male birds often have during mating season.

    Songbirds are those most often preyed upon by housecats in North America as these birds include common backyard favorites and many of the birds accessible to a hunting cat.

    Songbirds also have an abundance of rods in their eyes that help them detect bright color very well, even at dawn or dusk or in low light conditions. Their rods are specifically able to see bright colors.

    My own cat seemed to hunt in near darkness, at dawn, and he brought in deceased birds into the house through his cat door–until such time as I fashioned a bright colored cloth collar cover for him, and then, he never did bring in another bird.

    That was my story, of how I invented the product for one of the “worst” and highly skilled bird-hunting cats that I had ever heard of. My early customers had to sort of take my word for it, and try the product themselves. Customers were skeptical–and then, they were very happy to find it worked well for their cats too. But still, we were left with trying to create confidence by word-of-mouth until the science study came along.

    When my product was tested by a science study in North America, they found an average of 87% reduction in birds caught by cats that wear it. This was not a surprise to me or my customers. That is the expectation.

    So, in short, Birdsbesafe cat collar covers do work very very well in North America and Europe. We do have more to learn about the unique birds and needs in New Zealand and Australia, which we clearly describe on our website.

    As to customer satisfaction: Thanks to a carefully designed ( and patented product) that does what we say it does, we have many many happy customers, many repeat customers, and we are thriving in large part due to the word-of-mouth marketing that our customers do for us. There was in 2013, in the first half of the New York study, an issue with cat collars, as described in the study, which had poor performing buckles, and that led to some of the testers feeling that the “product” performed poorly because the buckles broke. It had nothing to do with the Birdsbesafe cover directly.

    If you can keep your cat’s indoors, great. If not, this is something worth trying to protect birds. To me, the numbers of birds killed by cats is too many, as long as tens of millions of cats go outdoors. Our product is a serious conservation tool, and we are proud to help save hundreds of thousands of birds. Thank you. I ordinarily wouldn’t write such a lengthy comment, but it seemed appropriate.


    • Al-Hajji Frederick H Minshall December 10, 2015 at 2:43 pm

      I must point out that claiming this ‘cat-collar’ would have any effect whatsoever toward preventing cat depredation on reptiles and amphibians is erroneous. Most reptiles, such as snakes, do NOT see color. The few turtles, tortoises and iguanian lizards that do are vegetarian, and their color vision is geared towards identifying edible plants and fruit, not detecting predators–i.e., they see the color yellow best. This will NOT help them avoid stalking cats because they associate the few colors they do perceive with food, not danger.

      Amphibians likewise do not see color–their visual acuity is stimulated by movement. Cats get around this by remaining motionless until they’re in a position to seize their prey. The collar will be of no value in helping frogs and salamanders avoid cat depredation.


      Thank you.


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