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.

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