Your pet cat is probably a killer but it doesn't have to be that way

When filmmaker Gavin Andrews took in an injured stray tomcat, he wasn't expecting his good deed to be repaid with the lifeless bodies of small birds.

"Taika survived outdoors for years, and he makes life miserable for everyone if he's not allowed outside. So at first, we were happy to oblige," says Andrews. "Then came the birds bits and pieces of them, scattered around the house. It was a nightmare."

Andrews wanted to know if he could take the killer out of the kitty. He shares his research in My Pet Assassin, a 17-minute documentary hosted by The Nature of Things's Sarika Cullis-Suzuki.

Cats are the most popular pet in Canada. Yet, despite their cute and cuddly reputations, our feline friends have a dark side: they are instinctive hunters that are considered one of the greatest threats to many rapidly declining bird populations. According to one study, outdoor cats are responsible for an estimated 100 million to 350 million bird deaths annually in Canada alone.

Conflicting opinions about cats

Canadians have strong and polarized views on free-roaming cats, as Annie Booth, a professor of environmental and sustainability studies at the University of Northern British Columbia (UNBC) in Prince George, found out in a recent survey she conducted.

"Indoor-outdoor or outdoor cats are actually pretty controversial for a number of different reasons. Some of it has to do with what cats do when they're outside wandering in their neighbour's yard. Some of it has to do [with] predation at bird feeders," Booth says in the documentary. "We ran a survey, and people either really liked cats and really sympathized with them and understood why they needed to go out or they really hated cats."

It's not a new debate. While some Canadian cities and towns have recently introduced bylaws prohibiting cats from roaming freely, animal welfare organizations and conservation groups have long made the case for keeping cats indoors, not just to protect birds and other wildlife but for the cat's own safety.

B.C.'s SPCA strongly recommends that pet owners keep their new cats indoors.

"It's really risky out there," Emma Hamill, manager of the B.C. SPCA animal centre in Victoria, says in the documentary. Common risks include contracting potentially fatal diseases and parasites, getting run over by cars and even being attacked by other predators.

Urban wildlife ecologist Jaylen Bastos can vouch for that. As lead researcher for the Vancouver Cat Count, Bastos processed and catalogued more than a million images from 34 cameras at over 80 locations throughout Vancouver.

At just one of these locations, the motion-activated camera photographed not only cats and birds but also skunks, raccoons and even a coyote. "[That was] very, very alarming, because those are one of the larger mesopredators that are going to be in direct conflict with cats," Bastos says in the documentary.

When Bastos saw their own cat, Keeta, photographed in the same location as the coyote, they started harness-training and adapting Keeta to a mostly indoors lifestyle. "While it was challenging at the start, it is something that I think has made his life much better," says Bastos.

Cat 'clown collars' could save lives

For Andrews, whose cat Taika has still not taken to indoor-only life, an alternative solution has appeared in the form of Birdsbesafe, a brightly coloured collar cover that makes cats remarkably visible to birds.

The device taps into the fact that birds have the ability to see a wider spectrum of colour than humans and small mammals.

Independent studies in the U.K., the U.S. and Australia have shown dramatic reductions in kill rates of birds by cats wearing the collar.

How this clown collar could stop cats from killing birds

7 months ago

Duration 1:55

The "BirdsBeSafe" cat collar may look like a clown collar, but its bright colours can warn wild birds of a cat's presence, preventing unwanted kills. Watch My Pet Assassin on CBC Gem.

In Canada, a recent study conducted by Booth and fellow UNBC professor Ken Otter confirmed this finding: "We found a significant reduction in the number of birds that were brought back, but not a significant reduction in the number of mammals." (Small mammals are essentially colour-blind, and the vibrant collars do not stand out for them in the same way they do for birds.)

The bright colours and reflective trimmings of the Birdsbesafe collar have the added benefit of making the cats more visible to motorists.

Between keeping his cat indoors after dark and letting him out for increasingly shorter periods during the day while wearing a Birdsbesafe collar, Andrews insists Taika hasn't caught a bird in over a year. "At least not one that's ended up on the kitchen floor!"