Do Cats Impact Wild Bird Populations? (by Chad Gooch, 11946)


chadpicI chose to focus on the environment and wildlife for my research and volunteer work. I have always had an interest in birds, so I chose to do a research project through the Scientific American website. The research project is a bird identification data base called Ebird where volunteers go online and record various species, numbers and locations of birds found during their outings. Songbirds across the U.S. are on the decline and the subject of house cat predation showed up in several publications that I read during my research. The question I came up with, which is the topic of my blog article is, “Do cats have an impact on wild bird populations”.

The bibliography below is a collection articles that discuss the impact of domestic cats that are allowed to roam outdoors as well as wild, or feral cats that live predominately outdoors. I found the information contained in the sources very interesting and honestly, quite shocking.

Songbird predation is a topic not many people think about and I am hoping that by bringing attention to it, it will provoke taking a deeper look. A lot of people who own cats like to feed birds and squirrels in their backyards. I am hoping that the articles below and the overall piece will bring awareness to the impact cats have on the very birds these people are attracting to their back yards.


  1. Ghose, Tia. “Cats Kill Billions of Animals a Year” Life Science . 29 Jan 2013. 03 Mar 2015 <>.  This article discusses the impact of cats on rodent and bird populations. Peter Mara, a prominent animal ecologist with the Smithsonian Conservation Biology Institute conducted a joint study that found that house cats are responsible for the annual deaths of up to 4 billion birds and up to 20 billion small animals, such as voles and chipmunks.
  1. Johns, Robert. “KittyCam” Reveals High Levels of Wildlife Being Killed by Outdoor Cats” American Bird Conservancy. 06 Aug 2013. 03 Mar 2015 <>.  The American Bird Conservancy cites a study by the University of Georgia that studied house cats and how they hunt and capture prey. The study was done by attaching video cameras around the necks of 60 house cats that are allowed to go outdoors. 30 percent of the cats sampled were active hunters and successful at capturing prey. These cats averaged one kill for every 17 hours outdoors, or about 2.1 kills per week.
  1. Raasch, Chuck. “Cats Kill up to 3.7B birds annually” USA Today. 30 Jan 2013. 03 Mar 2015 <>. This piece talks about not only the impact of cats on wild bird populations, but methods of reducing the environmental damage the cats are causing. One method mentioned is TNR, or Trap-Neuter-Return. This study is advocated by a group called Alley Cat Allies who defend the idea of free roaming cats. The goal of the policy is to gradually reduce outdoor cat populations while avoiding the more drastic measure of euthanasia.

Understanding the Issue

Almost everyone has heard of Sylvester and Tweety: the rambunctious cartoon cat and bird duo permanently engaged in an endless battle of gotcha: Sylvester constantly obsessing over how he will eat Tweety while evading the inevitable beat down with Grandmas broom. Believe it, or not life for real cats and birds is very similar. The only real difference is the bird ends up dead and Grandma doesn’t beat the cat.

A staggering 3 to 4 billion birds and 10 billion small animals are killed each year by house cats in the U.S. (Life Science). Some of these cats are from nice urban homes, while some are barn cats and many are feral, or basically wild and live outdoors. According to a study done by the University of Georgia, 60 cats were fitted with collar cams. Thirty percent of the cats sampled were successful at killing prey. These cats averaged one kill for every 17 hours outdoors, or 2.1 kills per week. “The results were certainly surprising if not startling”, says Kerrie Anne Loyd of the University of Georgia, who was the leader of the study. (American Bird Conservancy). That might not sound like a lot of birds on the surface, but when you consider there are 80 million cats spread across the United States, the numbers swell immensely. Dr. George Fenwick, President of the American Bird Conservancy states, “Cat predation is one of the reasons that one in three American bird species are in decline”. (American Bird Conservancy)

Many cats are feral and live outdoors full time. A group called Alley Cat Allies supports a TNR policy (Trap-Neuter-Release). This group advocates for feral cats and thinks that by sterilizing them the problem will stop. The only other alternative to TNR is euthanasia. No one wants to kill cats, but simply releasing them back into the wild is not effective. They just go back to killing birds for the rest of their days.

Four billion birds and ten billion small animals is a lot of carnage. If the public knew the total impact cats have on the environment, they may very well change their position and keep their cats indoors. Keeping a cat indoors is quite easy and the cats really don’t mind. Not allowing them to roam eliminates the impact to wildlife and the danger cat’s face when they go out for a stroll. Cats allowed outdoors can visit 10 different yards before ending up back home for bed time. (Life Science)

People love their cats and they have strong opinions about how they should be treated. Many think cats are made to roam and it’s unfair to keep them confined indoors. Well, I look at it differently. We have an orange tabby and his name is Dixie…He was a Christmas present and given that name by our daughter when she was 5 years old. Dixie is an inside cat. Because of worms, fighting, fleas and potential traffic related fatalities, we made a decision to have Dixie live with us as an indoor cat. He is now 14 years old and doesn’t look a day over five and is a handsome devil. He has never been sick, or had fleas, been cut up in a fight, or run over and his fur is always clean. The litter box is a snap as long as it’s changed every few days. He is also environmentally friendly and does not kill wildlife, or leave kitty rocha in the neighbors flower bed. If you really care about the environment, but can’t afford a hybrid car, keep your cat inside. This one simple deed is free, will save billions of birds and will do more good for the world than driving a Prius.

How to Get Involved

If you are interested in birds, or are looking for a great hands on volunteer opportunity that helps local wildlife, check out the Audubon Society. They are located in Portland, Oregon and perform many functions from rehabilitating injured birds to field trips that teach people about bird identification. The have a volunteer procedure which requires an application and a bit of classroom training. If you are interested, they can be reached by clicking this LINK.

Some people like a little less structure than a formal volunteer opportunity requires. If the independent Ebird program sounds more to your liking, you can click HERE for more information. Have fun and if you have kids, this is a great way to get them outdoors and teach them about wildlife. Good luck!



  1. Sarah Rudarmel

    I really like your Culmination Post. Although, I’m not gonna lie, it made me kind of sad. You see, I have an outdoor cat and I have come to the conclusion that he is one of the vicious predators that you are referring to. I know of him having 7 confirmed kills; 4 mice, 2 birds, and 1 baby squirrel. He has also come home with just a squirrel tail, and I have spotted a tailless squirrel around the neighborhood. I know that every time I witness one of his victims with him sitting next to it so proud I feel so sad. This isn’t the pet I want, some serial killer, but alas it is just in his nature.

    My story aside I enjoyed the thoroughness and thoughtfulness of your writing. I think you did a good job luring the reader in with creating the image of taking a nice walk and looking at beautiful bird, and then hooking them. The hook being those feline assassins. One thing that I would of liked to have seen is maybe telling people about a way that their cats could go outside and not create mass genocide. I understand that you are trying to promote indoor cats, and it’s awesome that it works for you but it doesn’t for my cat. When he is cooped up inside for too long he looses his mind, and then I loose mine. I think that in the how to help section you maybe could of talked about how if you don’t want an indoor only cat buy them a break-away collar that has a bell so that it will alert the intended prey of his almost impending doom, and give it time to flee or fly.

    As far as your grammar and sentence structure goes I feel you have a pretty solid handle on it. I think that maybe some of the writing could have been condensed a little as not to be redundant, but also if it wasn’t it wouldn’t matter that much. I did notice that this comment, “These cats averaged one kill for every 17 hours outdoors, or 2.1 kills per week“, was in the bibliography section and the understanding the issue section, so maybe a little more revision would have helped. All in all I think you have a really nice solid paper and did a great job!

  2. Travis Iverson


    After having the opportunity to read your first couple of essays in the class, which were both well written and fun to read, I would have to say that you saved your best work for last. I thought this article was very informative and covered a theme that involves a lot of people, whether they realized it or not. The numbers that you referenced are mind-blowing. I could have never imagined that cats kill that many animals every year. It really makes you open your eyes to the impact they can have.

    I think it was really smart to use as many statistics that you did. They really helped to support your claim. The article flowed very well and there wasn’t any point where I had to pause or re-read. I also really liked that you linked the topic to a cartoon, which added another relatable aspect to the work. Overall I think you did a fantastic job.


  3. Briana Robles

    I had no idea that this was even such a big issue! It was very interesting to read. I’ve had cats most my life and they were usually outdoor cats as well. I never stopped to think what they did while they were out there. Of course they would sometimes leave mice on the doorstep but I didn’t realize how big an impact their hunting could be on a species population. I don’t currently have a cat but if I do get one I will definitely be keeping this in mind!

    That Ebird program sounds very interesting I will have to take a look! This post was very informative honestly. It brought up a topic I’ve never even heard of before. Really great research as well I learned a lot from this reading.

  4. Jonathan

    Hey there Chad! Great blog post! I thought your Sylvester and Tweety paragraph was hilarious. I know this a serious issue but wrote a very entertaining post. You offered some great information that was relevant to your research question. I will add that birds caused a lot of destruction in the movie, The Birds. Good luck on the rest of the term!

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