Feeding the Feral: A Study on Feral Cat’s Environmental Impact.

Cat with mouse

Feral Cats on the prowl, an all to frequent sight while documenting urban wildlife. Some cast aside by their human owners, others born wild on the city streets, creeks, and open spaces. We decided to take a look at just two out of many 100s of feral cat colonies in wildlife designated areas of the Santa Clara Valley and examine the cat’s possible environmental impacts. By observing these cats we know that many species of wildlife fall prey to feral cats: Insects, rodents, reptiles, amphibians, and birds are impacted. All ground dwelling wildlife has to keep a keen eye about them when in the territory of a feral cat. These two colonies are in wildlife areas that are also habitat to many threatened and endangered species of wildlife like the Salt Marsh Harvest Mouse, Tiger Salamander, and the Steelhead Trout. Some cat colonies can grow quite large and consist of more than a dozen cats. These feral cat’s wild diet could possibly impact the available prey base for native predators like the Gray Fox and Red-tailed Hawk.

Another impact on wildlife associated with feral cats are the feeding Cat Feeding Station Adobe Creekstations. They are maintained by volunteers or private citizens to help keep cats healthy. Some feeding stations receive a delivery of multiple pounds of food each day. The feeding stations can often be found in or around wildlife designated areas. One sign we found on a feeding station, bordering the habitat of the small, ground nesting, Western Burrowing Owl read “this is a humane project for 100% benefit of our feline friends” but is it humane for the wildlife? We hypothesized that the cat food is not curbing the cats will to hunt. Like a house cat that is well fed, if its let outside it most likely will start stalking the first little creature it sees, hungry or not. Could it be their predatory nature?

Skunk at feedin station

After witnessing cats hunting in a few of these well fed colonies we began to discover that wildlife was eating the catfood as well. We found kibble in the scat of Raccoons and Gray Fox and Greg Kerekez personally witnessed skunks and many species of birds eating from the feeding stations. From his notes on May 14, 2012 he observed two species of bird, California Towhee and Oak Titmouse take the cat food back to the nest to feed their young.

Robbin with cat food  We focused our camera lenses on the piles of cat food and were amazed at the amount of wildlife that was utilizing these feeding stations. Bill Leikam set up a trail camera on a feeding station in the territory of 4 feral cats. The cats territory included a pickleweed marsh and meadow habitat which bordered an office complex where the feeding station was located. The feeding station is filled each afternoon Foxes at feeding station with over a pound of food, by an civilian who received the property owners permission to feed the cats. Bill also received the property owners permission to conduct the trail camera study of the cat feeding station.We’ve analyzed the first 11 days of video footage. Wildlife made 96% of the visits to the feeding station.

Two skunks and a Raccoon at feeding station

Night after night Skunks and Raccoons fought each other over the cat food. Skunks dominated the bowl with 74% of the visits, up to 5 skunks at a time would fight over the bowl, the Feral Cat feeding Station pie chart most aggressive skunk has a stomach the size of a beach ball, probably from eating so much cat food. Raccoons were next in line at 15% of feeder visits, some also looking overweight. The Gray Foxes made up 7% of the visits and were the most calmly tempered, they arrived early and shared the bowl with one another willingly and would quickly give it up if a skunk or raccoon entered the area.

Cat at empty feedin station

The targeted species, feral cats, made up only 4% of the visits and frequently arrived to an empty bowl. This means that wildlife is eating almost all of the food at this feeding station. We hypothesize that these feeding stations are influencing aggressive behavior in the wildlife and could impact the health and weight animals. With so many mouths eating out of one bowl this feeding behavior could also possibly aid in the spread  of disease.

5 Skunks at the bowl

The people maintaining these feeding stations would benefit from looking into how wildlife uses their feeders. They may be affecting the natural cycles and health of wildlife and the cats may be a minority at the feeders.  The feeders have many possible negative implications for wildlife. For wildlife’s sake, we might want to start looking at putting restrictions on cat feeding stations in and around wildlife designated areas.

We realize that one feeding station does not speak for all and at some stations  we’ve seen cats waiting to be fed when the feeders are filled. This is why more study of multiple feeding stations needs to occur. We encourage people involved in feeding the feral to monitor their feeders for wildlife activity and to not leave bowls of food unattended overnight.

To review the preliminary data from the cat feeding station click the link below.

Feral Cat Feeding Station Data ©Urban Wildlife Research Project 2013

12 thoughts on “Feeding the Feral: A Study on Feral Cat’s Environmental Impact.”

  1. There are four feral cats that have taken up living in my one acre garden in Los Altos Hills. They hunt the California Quail flock that passes through my yard every morning. They drink from the bird bath. If I put quail food out, they actually eat the seeds. They pounce on fledglings that sit on the ground. They love killing newly hatched quail. They toy with lizards and then don’t seem to eat them. I’ve seen them carry off the brush bunnies, which I enjoy seeing. I do NOT know if someone is feeding them. They do not appear to have clipped ears or to be neutered (as evidenced by regular litters of kittens in the yard). I’m wondering if someone is feeding them, because they look large and healthy. They hunt morning and evening, but I’ve never seen them eat what they kill. They mostly just toy with their injured prey. My feeling is that these rururbian feral cats are having a large impact on the native wildlife in my garden. Would you be interested in collecting mobile catcam data on the behavior of these rururbian cats? I’m thinking of a cam around the neck, so the cats movements can be tracked for a few days. I’m going to have to figure out how to trap them, before they breed again and cause even more damage. Maybe their behavior would be worth studying briefly, as relates to their impact on our local wildlife. Also, I think it would be valuable to find out if they are being fed at a feeding station.

    1. I should clarify my comment about the brush bunnies. I enjoy seeing the brush bunnies. I do NOT enjoy seeing the feral cats hunt them and carry them off. The brush bunnies seem to have an unfortunate defense of freezing in fear and defense, unlike the jack rabbits. I think real data documenting the activities of our local feral cats would be useful. They stalk the hummingbirds too, which is very sad to see too.

    2. Hi hun. I can understand that this upsets you. Why don’t you start a trap/neuter/return program for the sake of the creatures that more and more litters will impact? It doesn’t just have to be the cat lovers who do this…anyone concerned about a growing cat population would benefit from trap/neuter/return! These colonies start with just 2 cats dumped by an owner, and grow from there. If everyone would be forward thinking, they would trap any cats seen, and avoid colonies from starting or growing to a problem number. Since cats are considered a domestic animal, harming them is against the law, so the next best thing, even for someone who hates cats, is TNR.

  2. http://www.flickr.com/photos/johannacalifornia/7503299396/in/photostream/
    Here is a photo of a cat very near the feeding station(s) at Google, Shoreline Burrowing Owl Nesting grounds. I almost always see and can photograph feral cats in the Burrowing Owl nesting area (Vista Slope). The half-time park ranger at that time told me that in a six month period he had already trapped 24 feral cats in there. The cats seem to be fed at a colony feeding station but then continue to hunt in the Shoreline Burrowing Owl nesting area. I gave up on photographing the feral cats in the Shoreline Burrowing Owl Nesting grounds, because the park management seemed fully aware of the situation. It seemed that the feeding of a colony adjacent to the Burrowing Owl Nesting Grounds at Shoreline was contributing to the concentration of feral cats in a sensitive breeding bird nesting area. Not all the cats appeared to have been neutered, as I saw kittens as well. Whenever I’ve seen cats in the Burrowing Owl Nesting Grounds at Shoreline (Mountain View California) they are either sleeping or stalking. Feeding the cats doesn’t seem to prevent the stalking and hunting behavior. My photos and observations were from 2012. I do not know if the cat colony at Shoreline Mtn View has been terminated or relocated, but I hope it was removed. The TNR policies seem very destructive to local wildlife, in my observation.

    1. Feral cat with a catch, Shoreline, Mountain View, California  _MG_9790.jpg
      This is correct link for the feral cat with prey in the Burrowing Owl Nesting Grounds, where they hunt daily. I should add that there are no residences immediately adjacent to the nesting grounds, which is why I thought the source of dozens of feral cats was probably the feeding station at Google.

  3. The entire rationale behind Trap-Neuter-Vaccinate-Return (TNVR) is to reduce the number of stray and feral cats. And, I have to add this because everyone seems to forget — stray and feral cats are a PEOPLE problem — not a cat problem. People do not get their animals spayed/neutered as they should, they move and put the cat outside, and voila’, you have a stray cat that potentially becomes a feral cat. It is not the cat’s fault. People need to take responsibility for their pets, all of them.

    1. In order for TNR to reduce predation, it has to first reduce populations. To reduce populations, you have to neuter > 75% of the cats in the area (and by area I mean a city or town because if you just TNR a colony, you continue to have immigration and abandonment because of the food). TNR activities maybe reach 5% of the cats at best, and hence have no affect on overall population size. In addition, TNR does nothing to stop ongoing predation on native wildlife. Your best bet is to stop feeding and trap and remove continually. Feeding only increases resources and increased resources increases populations. It’s not rocket science. If I saw predation of native wildlife, I would buy a live trap and begin trapping and removing. If you think that is cruel because the cat may be euthanized, isn’t it more cruel to let it continue to kill native wildlife until it finally meets its own inhumane death from a car, a coyote, or a disease?

      1. Thank you so much for your response, Jim. The city I live in has a huge percentage of TNR’d cats, almost 75%. And, I do not buy into your inhumane death ideas, only because I currently have colonies that have cats that have cats who are 12 to 16 years old. That is because feral cats are smart, they receive adequate food/water/veterinary care from the caregiver (me), and they want to live a long, happy life like any other cat. I wish that you could visit my colonies and see for yourself how happy they are! And, over the past 15 years (and I am being totally honest), I have only seen 2 dead birds. I think that adequate food certainly helps.

        Thank you and if you consider trap and kill, just remember there will be more — it is not a solution.

  4. Unfortunately A.D., you’ve just proven that TNR does not work to eliminate or even significantly reduce the number of cats. You’ve been doing it for 15 years! And you still have colonies! If it worked as TNR advocates claim it does you’d be rid of your cats by now. And just because you rarely see dead birds does not mean they’re not killing them. Search youtube for “cat kills bird”. You’ll find well over 60,000 videos. I suggest you watch a few if you can stomach it. TNR isn’t humane for the cats, and it certainly isn’t humane for wildlife, which continues to suffer at the paws of these cats. Quit feeding the cats and eliminate other food sources. That would be a huge step forward in eliminating this problem.

  5. The proof that TNR works is in the Santa Clara County shelter statistics. 25% fewer stray cats and kittens have been brought into to our local shelter over the last few years, due to high-volume TNR effort, which slows the breeding and reduce the number of litters of kittens born each year. After the 25% initiial reduction, the shelters are continuing to see a continued 8 to 10 % in cats entering shelters each year. The trends and the ever shrinking number of free-roaming cats (owned or feral) being brought into locat shelters , shows that trapping & fixing all out door cats (tame or feral), encouraging resident to also spay/neuter their own pets, and encouraging folks when they adopt cats to keep them indoor only, IS working. Public education is the key here. Please promote responsibile pet ownership, and promote and encourage Spay/Neutering of all pets (either owned, or those allowed to roam outside) and encourage people to adopt from locat shelter (which take in and rehome outdoor cats) and for the new owners to keep them as indoor cats. Outreach and continued education to the public is the key….and it is working. Buy getting more people to spay their pets, tnr any all all cats they feed and keep those cats they own inside, we have already successful lowered the outdoor cat pupolation by 25% over the last 3 years ! Now , that is progress ! So, let what is working, keep working !! If we keep going at a 8 to 10% continued reduction rate, as has been demonstated in the local shelter statistics, we will actually be able to acheive what bird-lover and cat-lovers alike are BOTH striving for….FEWER free-roaming cats ! We are almost there folks….let keep working TOGETHER, and not against each other, to get there. We put too much energy into producing opposing views, when in reality bird-folk (who love all animals) and cat-folk (who love all wildlife) really are ON the SAME SIDE, we both want FEWER free-roaming cats, and those out there to finds homes ! So, let’s stop the silly back and forth fighting, and work on this together, to identify hot spots, so we can FIX them, and so that we can get to where we want to be….which is to arrive in a place where all species are protected and treated humanely by man.

    1. Thank you for your comment. Thank you to all who have helped reduced cat populations and to those who care about the felines and wildlife. You are right, we do need more education, for the public and education for the TNR folks that feed the feral. The majority of feeding activity I’ve witnessed has been harmful to wildlife. Better feeding training and techniques are needed to reduce impacts on wildlife. You can’t fix a problem by creating another. 5 Obese skunks fighting it out over cat food, in front of family owned businesses is not affective TNR.

      I agree we are on the same side, What you call “silly back and forth” I call discourse. We must continue debating and research to discover and adapt our efforts to make TNR even more effective at saving/protecting wildlife and reducing cat populations. Wildlife should not be eating an unnatural diet.

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