From My Window
Population Dynamics In Our Barn
By Jane Thibodeau Martin,
It seems like every month or so I run across a strident communication from someone, often in the conservation community, ranting about the number of birds killed by cats. Up front, I am aligned that cats allowed to roam loose do kill birds. So do a large number of other species, including our own. I suspect the reason we hear so much about this issue has less to do with cats killing birds, and more to do with the fact there are lots and lots of cat-haters.
A few weeks ago I was sitting on my brother's front porch in downtown Madison, WI at dusk, and was startled when a very large hawk landed on the lawn about six feet from me in Al's small front yard, snatched a bird out of an 18 inch shrub, and took off with it. Birds are yummy, and a lot of predators know it. We have a lot of snakes in Oklahoma that mostly eat rodents, but are also good tree-climbers, and love bird eggs. A few years ago I walked into the barn at the training stable where our daughter's horse was staying. Every horse was snorting, stomping and kicking their stall walls. Following their alarmed gaze, I saw a big Black Rat Snake (Pantherophis Obsoletus) crawling over the barn rafters toward some bird nests. This was a pretty impressive climb, and there is no doubt what the snake was after.
In the end, most scientists agree that habitat destruction and climate change are the most serious threat to bird populations " and most if not all of that has to do with human activity.
I am 100% in favor of not allowing cats to roam. My concerns have more to do with keeping my cats safe, along with my goal of being a responsible pet owner, than they do about protecting birds. But unfortunately, lots and lots of pet owners allow their cats and dogs to run free. It is a monumental task to change hearts and minds about these practices, and I don't look for it any time soon " although I am always doing my best to be a gentle persuader with those pet owners.
But my point in this essay is a bit different. Cats became associated with humans many centuries ago, and were highly valued in ancient Egypt. Their contribution to the human race was controlling rodents, which pilfered the hard-won food stores of early people. Back in those days, you couldn't keep your grain in well-designed grain elevators, or in steel garbage cans like I do. And your food stockpile was a powerful attractant for mice and rats. Thus cats, who kept this vermin under control, were working animals prized and protected by humans. In the Middle Ages, nearly 20 million people died in Europe from Bubonic plague " a disease that likely spread via infected rodents and their fleas, from city to city.
In rural America a century ago, all farms would host barn cats, again to control the rodent population. The cats, of course, had to be free to hunt, and some of these partners to farmers were not pets. But they were invaluable members of the farm's work team.
We have had an experience recently that reinforced to me what free-roaming cats still do for us humans. We have a very large pole shed, used to store many things, including my winter baled horse hay supply. For years, we tolerated a gap of several inches under one of the sliding barn doors, which resulted in a fair amount of critter invasion into the barn. I practice a "live and let live" philosophy as much as possible, so I didn't over-react to the skunks, snakes, mice, rats and other animals that made themselves at home in the barn " including the frequent visits of our neighborhood free-roaming cats.
But my tolerance eventually was ended with a population boom of possums. Possums are harmless animals in general, but they have one very bad impact for horse owners. Horses who consume hay that is contaminated with possum droppings can catch a very serious neurological disease called "EPM." A horse with Equine Protozoal Myeloencephalitis may suffer permanent nerve damage from brain lesions, and many horses never recover from this disease. So when we began to see possums in, on and under our barn hay supply, we poured concrete under the sliding barn door, reducing the gap they'd been using for access to less than an inch, which stopped the possum invaders permanently.
The "unintended consequence" of this effort was dramatic. In a very short time, the entire pole shed became alive with both mice and field rats. They scuttled along the walls, dove under stored equipment, and dashed along the floor. It didn't take long to see the impact of preventing the neighborhood free-roaming cats from hunting in our barn, and while a couple of mice is nothing to freak out about, we are facing a full-scale invasion.
Take whatever estimate you like about the number of birds killed by cats, times two; and you probably have an extremely conservative figure of the number of rodents killed by cats in a year. I can't speak to other environments, but I seldom see any evidence of bird killing by cats on our property. I see hawks hunting and killing birds, including in our fenced-in back yard; and encounter snakes up in our bushes, but the loose cats seem to prefer the easier pickings of barn-raised mice and field rats. And we are now providing the rodents with a cat-proof safe haven and are not too happy with the result. Luckily, I saw a very large Black Rat snake next to our barn recently with a good-sized bulge in his body, so I am hoping it sticks around. A few mice or rats are not an issue; dozens are a real problem.
If you are a rodent-hater, you might want to think about being a little more tolerant of loose-roaming cats. Or, if you are a snake-hater, remember that snakes love environments with lots of rodents. In the meantime, I'll be on my soapbox about neutering, spaying, and keeping cats and dogs home.
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