TED Conversations

Jon Cox

This conversation is closed.

Cats pose a serious threat to biodiversity: Why do we accept it? What should be done?

According to the ASPCA, there are around 90 million owned domestic cats (Felis catus) in the U.S., and taking into account strays and feral cats, the total number is estimated to be as high as 160 million (1). Loss et al. (2013) estimates that cats roaming outdoors kill 1.4-­3.7 BILLION birds and 6.9­-20.7 BILLION mammals in the U.S. annually (2). Reptiles and amphibians such as snakes, lizards, frogs, etc., are also frequently killed by cats.

Cats are even more popular New Zealand, where they are contributing to declines of endemic birds such as the critically endangered kakapo (3), which have evolved in the absence of predators. Businessman/philanthropist Gareth Morgan is trying to gather support for legislation that would aggressively deal with stray and feral cats and potentially eliminate cats from New Zealand to take pressure off of threatened species (4 & 5). With Morgan’s plan, in addition to regulation that would reduce cat populations and increase owner accountability, residents would be encouraged to not replace their cats. As of now the majority of New Zealanders surveyed are in opposition to Morgan’s initiative.

Would a proposition like Morgan’s meet similar resistance in the U.S.? Probably, but is he on the right track? Would you personally support something like it for your state or country? Why or why not is it a good idea? Is this type of legislation necessary to curb the problem and protect wildlife? If you disagree, what are some alternatives? Will the aesthetics and familiarity of cats keep them off limits to such ideas in the opinions of the general public?

1. http://www.aspca.org/about-us/faq/pet-statistics.aspx
2. http://www.abcbirds.org/abcprograms/policy/cats/pdf/Loss_et_al_2013.pdf
3. http://www.avianweb.com/kakapo.html
4. http://www.npr.org/blogs/thetwo-way/2013/01/24/170191917/new-zealand-environmentalist-wants-to-eliminate-cats-to-save-birds
5. http://www.livescience.com/26525-cat-eradication-new-zealand-save-birds.html


Closing Statement from Jon Cox

Thanks to everyone who contributed to a thought provoking discussion!

I think we can all agree that we need to be responsible with our pets! For the sake of ecological and human health. And pet owners must realize that their carelessness is costly. Plans to completely eliminate cats from areas where they are very popular are pretty far fetched, but stricter regulation is a must, and domestic cats do NOT belong in the wild, period. Feral cats need to be seen and dealt with just as any other invasive species. However, extreme caution is necessary in any attempt to remove them where they have become established as a keystone species.

Check out Australian cat laws for a look at the legislation adopted by a people who cherish their native wildlife and do not want to see it be destroyed by invasives.

And lastly, we must keep in mind that invasive species are just one way in which we threaten biodiversity. Overexploitation and especially habitat loss pose even greater threats to species survival.

Thanks again!


Showing single comment thread. View the full conversation.

  • thumb
    May 7 2013: I find it pretty ironic to call for the elimination of cats as pets because of their effect on bird biodiversity, when humans are directly causing the loss of so many other species. You could argue that legislation to limit the population of humans in the US should be implemented, because "it is for the greater good and humans are just too destructive to justify", but of course most people would not support that. Similarly, the majority of people will never support a decision to make cat ownership illegal. There has to be a balance. I do not think it is reasonable to force people to give up pets, a major source of enjoyment and entertainment (a provider of "cultural services", if you will) to protect other species that the general population, to be honest, probably doesn't care all that much about.
    I think the focus should be on public education and on feral cat population control. The people who are most likely to want to donate their time and resources to organizations that advocate things such as the protection of bird biodiversity are probably animal lovers, and therefore are likely to keep pets themselves. If we increased public education that let people know that regulating their cats' outdoor activities could lead to more beautiful birds gracing their feeders and yards, I think people would be much more receptive to the idea that cats harm bird biodiversity. As another person mentioned, putting bells on cat collars is a great idea. Outdoor cats without bell collars could result in their owners being fined, similar to the concept of keeping your dog on a leash. Finally, I think increased control on feral cat populations would have a big impact, especially in the US. One study found that over two years, trap-neuter-return approaches decreased feral cat populations by 36%; without TNR, populations increased 47% (Stoskopf & Nutter). It's not perfect, but it's a much more balanced and reasonable approach to this issue.
    • thumb
      May 7 2013: Very well said. I had intended to create a post expressing similar sentiments, but you've saved me the trouble. :)
    • thumb
      May 7 2013: I can also see the irony in the situation, and the reason there are so many cats destroying other species is because of human domestication and breeding so I think it's reasonable for a need for more regulation and accountability for cat owners and even the general public. I agree that there should be a focus on feral cat population control but honestly, from experience volunteering with an animal rescue group, there are just too many feral cats for people to deal with, at least the small amount of volunteers and workers that care enough to deal with them. But I agree that this issue should be more publicized because people probably don't realize how much of an impact their house pets can have on biodiversity. Maybe there should be a government funded program in each city for trap-neuter-return methods instead of rescue groups applying for grants and using finite resources to deal with the issue.
    • thumb
      May 7 2013: I agree that it is silly for people to point the finger at cats when we are doing the most damage, it's just easier for us to fragment and change each destructive behavior rather than step back and see ourselves as a problematic species. I wonder if the law is harder on dogs because they have the potential to injure or kill humans and destroy property, whereas cats can only harm smaller organisms. If cats were as big as most dogs, there would certainly be a lot of restrictions. So much of our behavior and legislation is centered around human well being, with no regard for our neighbor species, that seems to be a theme of this class.
      • thumb
        May 7 2013: You are right Ryan, humans are egocentric so lets use that to bring light to this issue. Conservation efforts can use that fact to not only inform the public of the harm that felines do to our ecosystems but also the danger they pose to us. Cat overpopulation can be linked to extinction but also the spread of disease to humans and other organisms.
    • thumb
      May 7 2013: This is a great point, I wonder how the two threats compare in terms of scaling. Humans do more diversified and global damage for sure. They are also responsible for domestication and export of cats around the world. Rather than seeing cat-caused destruction as separate from human caused destruction, the loss of biodiversity due to cats is actually just an extension of human caused destruction.
    • thumb
      May 7 2013: I do think that human populations need to be limited and that we could offer financial incentives to people who choose to have only one or two children.

      I think the focus has already been on public education and feral cat population control but that hasn't worked.

      The fact that we humans have introduced cats to environments that previously didn't have such excellent predators and that we let their numbers grow to the point of destroying other species is pointing the finger more so at humans than cats, they're just doing what comes naturally.
      • thumb

        Jon Cox

        • +1
        May 7 2013: Exactly. It is not the animal's fault what so ever. It is a man made issue. Cats just do what they do, but we have engineered a serious problem by spreading them across the globe and turning a blind eye to the damage they do for so long. Destruction caused by domestic cats is just another way in which we are putting unsustainable pressure on our environment.

Showing single comment thread. View the full conversation.