As part of my job, I give many talks to gardeners and landowners on how to attract wildlife to backyards. Part of the program always leads towards a discussion on whether or not to keep domestic cats outdoors. Most biologists, including myself, recommend keeping cats indoors. There are an estimated 148-188 million domestic cats in the U.S. Several published studies have documented the predation of native wildlife by domestic cats. A recent study published in the journal Nature Communications estimated the annual toll to exceed 20 billion animals each year with the vast majority being wildlife (that is, very few house mice and rats).
In full disclosure, when I was young, we kept and cared for several cats (1-4 in a year) outdoors over the years. We fed and watered them and had them “fixed.” Despite this, I witnessed them bring home baby rabbits, shrews and chipmunks. Occasionally, some would hang out by the bird feeder. Back then, we thought they helped control pests around the home and yard. So the cost of a few critters over the years was all right because how much damage could a few cats do, right? Wrong.
I didn’t know any better then, but I do now. America’s domestic cats kill between 1.4 to 3.7 billion birds each year. This new estimate exceeds annual mortality rates by birds caused by pesticide poisonings or from collisions with windows, communication towers or vehicles, according to an article published in Science News. Why isn’t more attention paid to this issue? Dealing with feral and domestic cats can be a tricky problem, and it often becomes a social issue with neighbors. Last year, my neighbors took in a cat they found. It turned out she was pregnant, and she had a litter. The good news is they did the responsible thing and had them all fixed. They gave one away to another family but have had problems finding homes for the rest. In the meantime, they have free access to the outdoors. Even though they have the best intentions, I still have found them chasing squirrels in my yard, sitting under my hummingbird feeder, killing a bird in their yard and chasing a chipmunk up the side of a house.
There really is no easy answer to this dilemma. In the short term, responsible pet ownership is a start, but it doesn’t help deal with the 60 million or more feral cats that run free in the U.S. An excellent publication on cats and their management by the University of Nebraska-Lincoln Extension was published, Feral Cats and Their Management.
Nature Communications Article, The Impact Of Free-Ranging Domestic Cats on Wildlife of the United States
Science News Article, Cats Kill More Than One Billion Birds Each Year: New Estimate Suggests Hunting Felines Take Bigger Bite Than Expected Out Of Wildlife