Counting Feral Cats
Now that feral dogs have virtually disappeared in the United States and the supply of homeless dogs is approaching balance with demand, attention is increasingly turning to feral cats. Cats in general, and feral cats in particular, are now the great issue in the effort to save all healthy and treatable shelter animals.
One practical problem we face at the outset with feral cats is that we do not know how many there are. We do not even have any good estimates – just guesses.1
There is a way to work around this, though. The absolute number of feral cats today is less important than the trend in their numbers over time. So how can we figure out the trend? The first step is to go where the cats are. Free-roaming cats, including feral cats, are highly concentrated in urban environments. 2
The reason is that urban environments provide far greater opportunities for scavenging and far greater concentrations of food resources and shelter than agricultural and uninhabited areas. In fact, the number of free-roaming cats per unit of ground in cities is more than 20 times the number of free-roaming cats in rural areas. 3
The second step is to look at shelter intake of cats over time. If, after correcting for variations in enforcement, the trend in cat intake is up, then we know that whatever the community is doing as to feral cats is not working. If the trend is down, then we know the community is on the right track.
You might be wondering how shelter intake of cats in general can indicate the trend in feral cat populations in particular. After all, the majority of shelter intake of cats is owner surrenders and strays. And lots of shelters do not take in feral cats at all. The reason that shelter intake of cats reflects the number of feral cats is that the feral cat population is not separate from the cat population as a whole. Gary J. Patronek, one of the premier experts on population dynamics in both cats and dogs, has pointed out that there are seven common lifestyles for a cat: indoor-only, indoor-outdoor, community cat, stray, managed colony, barn cat, and feral cat.4 The key to cat population dynamics is that these categories are not hard and fast. In fact, cats frequently move from one category to another. Thus, the feral cat population will tend to rise and fall with the general cat population. And the intake of cats at the shelter is an even better indicator of the trend in the feral cat population than the number of owned cats in a community because shelter intake is limited to homeless cats, which is the category that includes feral cats.
The Jacksonville, Florida, city shelter provides a good example of how shelter intake over time can track the free-roaming cat population. Florida, with its balmy weather and relative lack of mesopredators, is heaven for feral cats, so Jacksonville is second to none in the difficulty of the feral cat problem it has to solve. Yet cat intake at the city shelter began to decline when the Feral Freedom shelter-neuter-return program was started in 2008, and is now at its lowest point since accurate shelter statistics began to be kept.
To sum up, all we need to do to determine whether we are making progress in reducing feral cat numbers is look at shelter intake trends in cities. We look at cities because that’s where the feral cats are, and we look at shelters because that’s where the homeless animals go. We look at trends rather than worrying about absolute numbers because trends tell us whether we are making progress or not. We don’t have to be fussy about what types of cats a shelter takes in, because all cats are part of the overall cat population that feeds the feral cat sub-population.
In recent years there has been debate about whether we need to keep putting resources into further reducing shelter intake of dogs in communities where live releases of dogs are high. With cats we clearly do need to keep putting resources into spay-neuter efforts, because ideally we would like to reduce the number of feral cats to zero. The problem of feral dogs was solved long ago in most places in the United States. The problem of feral cats has been harder to solve, but the results in Jacksonville show that not only can we solve the problem, we can solve it rather quickly, without any mass roundup or mass slaughter of cats.
1. Scott R. Loss, Tom Will, and Peter P. Marra, “The impact of free-ranging domestic cats on wildlife of the United States,” Nature Communications 4, January 29, 2013, Supplementary Information: doi:10.1038/ncomms2380.
2. Terry O’Connor, Animals as Neighbors: The Past and Present of Commensal Animals (East Lansing, MI: Michigan State University Press, 2013), 57-66.
3. John W. S. Bradshaw, The Behavior of the Domestic Cat, 2nd ed. (Wallingford, UK: CAB International, 2012), 140.
4. Gary J. Patronek, “Special Report: Free-Roaming and Feral Cats – Their Impact on Wildlife and Human Beings” Journal of the American Veterinary Medical Association 212, no. 3 (January 15, 1998), 218.