Citizen Science

Tracking the Secret Lives of Cats

November 3, 2015

Follow Lisa
Domestic cat (Felis catus). Photo © R∂lf Κλενγελ/Flickr through a Creative Commons license

Is your cat ‘cheating’ on you? When you let your kitty out for a stroll, where does she go? What risks does she take and is she a threat to local wildlife?

You can find out with Cat Tracker and the answers may surprise you!

If you have an outdoor cat and are willing to build a GPS harness, you can participate from anywhere in the world. In just two weeks you can learn about your cats’ secret travels and trysts.

What Is Cat Tracker?

It all started with a friendly bet between Roland Kays of the North Carolina Museum of Natural Sciences and Rob Dunn of North Carolina State’s Your Wild Life group.

“Roland had recently done some work with ocelots and wondered why there weren’t any large scale studies on domestic cats when you could use a similar sized collar to that of the ocelots,” says Troi Perkins of Cat Tracker.

The two decided to track Rob’s cat Chica for a weekend and see where she went.

Chica's incredible journey. Image © Cat Tracker
Chica’s incredible journey. Image © Cat Tracker

One day Chica, an older cat, surprised them by traveling more than a mile to visit Rob’s old house.

They created Cat Tracker so that researchers can collect data on the secret habits and habitats of outdoor cats with the help of cat owning citizen scientists

Participants put a GPS harness on their cat for two five-day periods and upload the data to Cat Tracker to learn where their kitty goes and contribute data about the general trends in cat habitat use.

Why Is Cat Tracker Important?

You might have read about a study in Nature that estimated free ranging cats in the United States kill 2.4 billion birds and 12.3 billion mammals annually (median estimates).

Many people are skeptical about the estimated impacts of cats on wildlife and even more skeptical that their own pet could have an impact.

By bringing in cat owners as participants in the data collection, Cat Tracker gives individuals a chance to see where their own cat is going and judge what impacts that might have on local wildlife and the safety of their cat.

“We really hope that cat owners will take the data collected into account and see that cats are traveling beyond just the backyard and could be endangering themselves and native wildlife,” Perkins reports. “The ultimate hope is for cat owners to keep their pet cats indoors where it’s not only better for native wildlife but safer for their kitties as well.”

A map of one cat's travels. Image © Cat Tracker
A typical map of a cat’s travels. Image © Cat Tracker

Many owners have learned surprising truths about their cats; taking long walks to wild areas, crossing highways, and even making regular visits to other neighborhood houses. Yes, Perkins reports that some cats ‘cheat’ on their owners.

Learning about these risks has already prompted some cat trackers to bring their pets indoors for good. And as Perkins says, the data is only half the story.

“Really one of the best things about Cat Tracker is the fact that it connects the public to scientists and vice versa,” Perkins notes. “The most common thing I have people say to me is that they feel like they are truly making an impact (and they are).”

How Can You Get Involved? 

Learn all about participating in Cat Tracker on their website.

Certain locations (Raleigh/Durham, NC, Long Island, NY, Fairfield County, CT & Westchester County, NY) have GPS trackers available to loan.

For other locations, Cat Tracker has instructions on how to make your own DIY cat-tracking GPS harness. If you have kids and the money to pursue this option, it may add to the fun of the project wherever you live!

There is an optional, extra step to find out what cats are eating outside. You can send cat hair and food to Cat Tracker for isotope analysis. By comparing the isotopic signature of the hair to the food, researchers can tell if the cat is getting food in the wild (wild birds and mammals).

If you have a cat that you let outdoors on a regular basis, discover their secret life and contribute to science with Cat Tracker.

Please do not let indoor only cats outdoors for the study!

Lisa Feldkamp

Lisa loves all things citizen science and enjoys learning about everything that goes on four legs, two wings or fins - she even finds six and eight-legged critters fascinating at a safe distance. She has a PhD in Classical Literature and Languages from the University of Wisconsin - Madison and enjoys reading Greek and Roman literature or talking about mythology in her spare time. More from Lisa

Follow Lisa

Join the Discussion

Please note that all comments are moderated and may take some time to appear.


  1. Since losing my friend, Puss, in 1980 to a speeding driver I have stopped allowing my cats to roam. The farthest our four cats go is the backyard, which is fenced in. They are also watched to ensure they don’t find a way out. For the most part they’re content, even though one was a “throw-away” cat, and a second was born feral. We do our best to ensure they don’t kill the visiting birds…although it doesn’t entirely work. Alex (the ex-feral) just can’t help himself, although he knows he shouldn’t do it.

    1. Please tell us that you are kidding when you say your cat “knows” that he shouldn’t kill birds.

  2. Another subject for research that could be done through cat hair analysis is environmental contaminants. Very little research has been done using domestic, free-roaming cats as the subject. In a few cases cats have been early indicators of human exposure, (Minimata, Japan). Cats lay in the dirt, brush against vegetation, get dust on their hair, and eat any all sorts of things including wildlife. Hair analysis can reveal what contaminants-including pesticides, herbicides, heavy metals, rodenticides, etc., they are encountering. These substances can cause health effects-cancers etc., in cats. Perhaps another reason to keep cats indoors. Possibly identifying sites with risks to human health.

  3. Cats do not belong roaming. Why would you encourage a GPS tracker above containing a cat? Since cats don’t eat all of their kills, how is testing hair going to show what the cat is mauling and leaving for dead? This “study” will prove nothing that has not already been shown….that cats are an invasive domestic species that need to be contained.

  4. I have 4 cats and all of them were taken from the outdoors roaming. They were not doing well. Skinny and starving. Why anyone would let their cats roam is beyond me. You are not doing them a favor and you are subjecting them to all kinds of danger. I worked in a veterinarian’s office and saw first hand what it leads to. I let my cats out in my backyard supervised then they come back into the safety of my home. Cats do NOT do well left to their own devices. It is a cruel thing to do to just set them free.

  5. I have a question about the isotopic analysis for determining dietary indiscretions by the roaming cats. Since cats that are well fed often don’t consume their prey items, will those prey species show up in the isotopic analysis?

  6. Great read for anyone with outdoor or indoor/outdoor cats. Most people don’t realize the impacts that cats have on native wildlife. They kill for sport, not out of necessity like other predators.

  7. “Outdoor cats” is nearly synonymous w/ neglected cats. It’s a euphemism most often used to disguise one’s neglect of their pet and the wildlife it encounters when left to roam free.

    I’d like to see the the two words replaced w/ something more meaningful, like “Cats w/ poor caretakers.”

  8. If it was revealed that 2.4 Billion song birds and 12.3 billion mammals and who knows how many reptiles and amphibians were killed by poachers say for the market, there would be outrage in the environmental community. This issue instead goes way under the radar because it’s a pet and is obviously a huge problem for wildlife of all types. Kudos to Lisa for bringing this issue to press, lets hope it gains some momentum and that cat owners all over the country will take note and accept their responsibility for their part in this. Keep your cats inside!

  9. Some of you people are living in a dream world of ecological denial. Animals, including humans, do not live in a Disney world where they all congregate happily in the forests. Inherent to ecology is the phenomenon of predator and prey. Before the statistics came out concerning the number of animals they do kill, it’s not like the world was living in an anarchy of bird, small mammal, and reptile disappearances. Our ecological balance between cats and their prey was/is fine, except for loss of habitat and environmental contamination, which are the real giants we need to slay.

    It never ceases to amaze how much people project their own thoughts and feelings onto animals. Just because someone is opposed to people hunting animals for sport does not mean you can project that onto cats.

    Similarly, when people never let their cats outdoors, they are really NOT trying to protect the animal but their own feelings of loss should their kitty die. I’ve been very sad whenever my pet cats died, but I take a little solace in knowing I provided them with the life they were meant to have. Everything about the cat is designed to be a carnivorous hunter, so locking them up indoors, where they can never explore their nature, is wrong. It makes the most sense for our pet cats to be both indoor and outdoor animals. It is a bitter pill to swallow, but if you TRULY care about your cats–and I mean REALLY care for their freedom and innate behavior–you will get over your selfishness and allow them to go outdoors to explore.

    1. Hi Steve, I agree with you. I live in the woods with no one around, and my cats are allowed to go out from time to time throughout the day if we are home. I want my kitties to have a whole life as nature intended. I know they catch critters from time to time, and I intervene, but sometimes I don’t get there in time, and I’ve come to the conclusion that it’s going to happen, and it gives my kitties a release and freedom. I would not keep my dogs locked in a pen because they hunt critters on the property. It’s their nature, and when you fool with nature, there are consequences. I do love birds, and I try the utmost to keep them safe. I recently read an article on ultraviolet cat collars that birds can detect so they will not go near the cat, but I cannot locate where to purchase them or if they’re even on the market yet. I actually have the ultraviolet decals on my windows so birds do not crash into them. So, yes, I love critters, but my kitties have their natural instincts, and I don’t want to keep them shut in a house without fresh air, sky, nature. Even if I lived in an apartment with no outside, I’d build a catio on the window or something. It’s that important for them. Others – please do not judge me for letting my cats outside. I’d rather my cats have a great ten, exciting years instead of a boring, anxious 20 (but my kitties have lived well beyond ten…) thank you.

      1. One more thing – we recently went away for a week, and on our return, squirrels had built a nest under our house in the roof (we have a stilt house), and they had sprung a leak by biting through pipe. I believe they nested there because our kitties were not outside to chase them away that week (just last week). thank you – Sharon

    2. You ignore the fact that cats – domestic cats – are not part of our ecosystem. There was zero balance before between cats and anything because they didn’t exist here. You might want to actually study ecology some and you’d learn why the dodo went extinct as one of many examples of the genuine ecological problem of domestic cats.

  10. I have an indoor cat and I get worried about his health an welfare. For someone who can take an innocent cat off the streets and to kill them for research is just not right. It’s cruelty to animals and they should be in jail. IT’S WRONG!

    1. Hi Cynthia, I understand your concern for outdoor cats. The study does not encourage anyone to put cats outside – it only encourages people who already let cats outside to track them and see where they go. One of the goals of the study is that, armed with that knowledge, people will choose to keep their cats safely indoors.

  11. Thanks for this fascinating article! It can only help, to have more cat owners understanding how far their cats range, and then hopefully make informed decisions to protect birds and other wildlife.

    Following the link to the “DIY cat-tracking GPS harness,” and the link to the main component (a GPS tracking device), it turns out that the GPS devices are sold out.

    According to that link at, many people who bought this item also bought cat harnesses. So this seems to be inspiring a lot of people to participate in the study!

    1. That is good news! I hope that people find an alternate means of buying the GPS device for the time being.

  12. I presume you know this was done in Shamley Green, Surrey, England for the program Horizon in June, 2013. It was such fun to be able to follow the cats on their journeys. My cats are all indoors for a variety of reasons, but I grew up on a farm here in the US and all our cats were “outdoor” cats.

  13. We used to have indoor/outdoor cats, and one, Magpie, who was a stray who adopted us, did in fact “cheat” on us with a neighbor up the street and around the corner. He liked to eat, so he sometimes went to this other family where they often fed him–he had plenty at our house too. But, Magpie considered us his “first” family. We only found out about the other family when one of my best friends, who is a next door neighbor of that other family, saw Magpie at our house and told me that she saw him at her neighbor’s who also fed him. He knew how to game the system, alright. But, he was also injured one winter, when either a dog or a car caused him an injury that resulted in his tail being amputated; he was fine without it, and in fact looked just like a stumpy Manx; no one knew he wasn’t born that way, but everyone who ever saw him said, “what a BIG cat!” He wasn’t fat, just huge. I would have liked to have put a GPS tracker on him, because I am sure he roamed the woods in front of and behind our house, and who knows how many other families! But, since he died, none of our four other cats have ever gone outdoors; in fact, they were all rescued from “the street” (or countryside, in the case of my in-laws’ farm) where they had been abandoned as kittens, and none of them have ever seemed to want to go back out to “the street” although they thoroughly enjoy “looking out” at special perches around the house where they can see what goes on through windows and glass doors. They are perfectly content to live indoors, and they are safe from traffic and other animals. I don’t worry so much about “wildlife” kills, because my mother-in-law’s farm cat has rid her yard of mice, moles, shrews and other vermin. He is a one-eyed cat, and is fed as well, so I think he is too slow to get birds, although my mother-in-law wouldn’t mind if he rid her feeder of English Sparrows.

  14. Cats have been known to devastate bird population, especially singing birds and migrating exotic birds, not familiar with local conditions and potential dangers. Tracking cats is a good idea if an owner really wants to learn where the cat(s) is wondering . Most owners don’t care. The only simple and cheap solution is putting a collar with little jingle bell on the cat. The tiny bell is warning birds and they have time to fly away from danger. The pet supply chain stores ( many of them serve as adoption centers for stray cats) offer these collars for $5 and may inform potential adopters about devastating effect of cats predation on birds, amphibians and other small animals. These collars may even be donated to adopters along with the printed information flyer.