Cats, turds and birds

Keep cats indoors for the sake of your garden and the birds

Cats are the perfect indoor pet. Affectionate and curious, they make great companions. Give them a toy and they will amuse you with their antics. Nothing is nicer than a purring feline welcoming you home after a long day at work.
 
However, cats that roam outdoors can cause problems for gardeners and birds. They are voracious hunters of birds and may use gardens as a litter box.
 
Allowing cats to roam isn’t just bad for gardeners and birds, it’s bad for cats too. Free roaming cats are exposed to all kinds of risks including vehicle accidents, aggression from other animals (including other cats), and infectious diseases and parasites.

Impact on Wildlife and Human Health

According to a 2013 study, cats are the number one killer of birds in Canada, killing a staggering 300 million birds per year. Birds are on the front line when it comes to insect control. ScienceDaily reports that birds around the world are estimated to eat 400 to 500 million tons of insects every year. A healthy population of birds is important to garden eco-systems. Their  appetite for insects, especially larvae and pupae especially when they are feeding their nestlings, naturally keeps pest insect populations in check.
 
Cat turds (feces) are a serious soil contamination problem, especially if they choose your vegetable garden as a litter box. Cats shed a parasite called toxoplasmosis in their feces, which can cause serious health problems for pregnant women and people with compromised immune systems. Their feces may also contain roundworm, hookworm, E. coli and/or salmonella, all of which can cause serious illness.

How to Help Your Garden

If the damage is already done in your garden:
  • Wear gloves and remove the turds (feces) and as much of the soil as you can as soon as possible.
  • Remove any vegetables growing near the contaminated soil.
  • Dispose of the soil and plants in the garbage, not the compost.
  • Disinfect any tools used in the garden with isopropyl alcohol, hand sanitizer or Lysol.  Disinfect your gloves and boots too, well away from the garden area.
  • Do not plant root vegetables (carrots, beets, potatoes, parsnips) or any leafy greens that are eaten raw (lettuce, chard, kale) in soil that was heavily used by a cat.

Cats prefer soft, dry soil for digging and are attracted to bird baths and bird feeders. There are some things you can do to deter them from using your garden as a litter box.

  • A thick layer of woody mulch (at least 4”) over bare soil in your garden will discourage digging.
  • Cover plants with floating row covers to prevent access to the soil.
  • Chicken wire is an effective deterrent when laid over bare soil.
  • Cover unused raised beds with a tarp or wooden panel when not in use - same goes for children’s sand boxes. 
  • Motion activated sprinklers can deter cats.

What to Do About Cats at Large

Just like dogs, most municipalities have bylaws that require cats to be licensed and are not allowed to roam at large. Responsible cat owners give their kitties outdoor time supervised on a leash or in a “catio” (enclosed outdoor area) and create indoor play activities to keep them entertained and give them exercise. If a cat at large is a problem, contact your local Humane Society, SPCA, Animal Shelter or the pound.

Feral cats, however, are an even greater concern, as they rely on hunting for sustenance and their populations multiply quickly if left unchecked. If a feral cat is living in your garden or yard, contact your local Animal Shelter, Humane Society or SPCA for help finding local programs that trap and neuter feral cats

Frequently Asked Questions

Q: My cat is a mouser, and she does a good job killing mice in my compost. I would prefer to keep her inside but what can I do about the mice in the compost? Is there another way?
 
A: Mice are an occasional problem in compost bins. Mice can be deterred by keeping the compost moist and turning the compost often. The moisture and disturbance will keep them away. Use mousetraps as well to keep mice problems down.
Keep in mind that mice carry parasites which may be harmful to your cat and some parasites can be transmitted to humans. Consult your veterinarian.
 
Q: My cat Herman is an escape artist and I have a hard time keeping him indoors. I put a bell on him, but he still comes home with dead birds. What should I do?
 
A: Cats wearing bells soon learn to move without making the bell sound. Felines will patiently lie in wait and pounce on prey. By the time they pounce, the bell sound is irrelevant.  
 
There is a product called a CatBib – a polypropylene bib - that permits movement but prevents most cats from hunting successfully. A 2008 study showed 81% of cats wearing a CatBib were not able to kill birds which is great improvement. A CatBib may be a good option for escape artist cats. You can find more information about it here: CatBib
 
A CatBib greatly reduces bird deaths, but if your cat is still using the garden as a litterbox, it may be time to consider building a catio (enclosed outdoor space).

Sources

An overview for caring for free-roaming cats. (n.d.). Humane Society of the United States. https://www.humanesociety.org/sites/default/files/docs/caring-feral-cats-overview.pdf

Birds eat 400 to 500 million tons of insects annually: Along with spiders, insectivorous birds play a vital role in consuming insects that would otherwise destroy forests or crops. (n.d.). ScienceDaily. Retrieved 9 August 2022, from https://www.sciencedaily.com/releases/2018/07/180709100850.htm

Calver, M., Thomas, S., Bradley, S., & McCutcheon, H. (2007). Reducing the rate of predation on wildlife by pet cats: The efficacy and practicability of collar-mounted pounce protectors. Biological Conservation, 137(3), 341–348. https://doi.org/10.1016/j.biocon.2007.02.015

Calvert, A., Bishop, C., Elliot, R., Krebs, E., Kydd, T., Machtans, C., & Robertson, G. (2013). A synthesis of human-related avian mortality in Canada. Avian Conservation and Ecology, 8(2). https://doi.org/10.5751/ACE-00581-080211

Cats in the garden! What to do? (n.d.). University of California, UCCE Master Gardener Program. https://acmg.ucanr.edu/files/214548.pdf

Chaudhry, S. A., Gad, N., & Koren, G. (2014). Toxoplasmosis and pregnancy. Canadian Family Physician, 60(4), 334–336. https://www.cfp.ca/content/60/4/334

How birds keep our world safe from the plagues of insects. (1995, January 1). Smithsonian’s National Zoo. https://nationalzoo.si.edu/migratory-birds/news/how-birds-keep-our-world-safe-plagues-insects

Loyd, K. A. T., Hernandez, S. M., Abernathy, K. J., Shock, B. C., & Marshall, G. J. (2013). Risk behaviours exhibited by free-roaming cats in a suburban US town. The Veterinary Record, 173(12), 295. https://doi.org/10.1136/vr.101222