Monday, April 13, 2020

The Ethics of Anti-Squirrel Bird Feeders

Today is Easter, and in keeping with the tone of that holiday, I thought I'd look at something a little lighter for a change:  the ethics of squirrel-preventing bird feeders.

First, we identify the cast of characters.  There's the people who like to provide food for birds, in exchange for getting to watch the birds feed.  Next, there's the birds, who don't really have a downside in this deal, except when the squirrels get into the act and make less food available for the birds.  Third, there are the squirrels, who have to eat too, and are not to blame for the fact that watching them eat is a lot less interesting to people than watching birds eat.  And fourth, there are the companies and individuals who make bird feeders and exercise their ingenuity to make sure birds get the seed and squirrels don't. 

Maybe you haven't given the slightest thought in your adult life to birds or bird feeders.  But believe me, folks have been trying to come up with ways to stop squirrels from filching from bird feeders for decades, if not centuries.  A physics professor named Rhett Allain who blogs on the Wired website about physics in ordinary life came across a particularly clever technique.  It's a feeder put out by a company called Droll Yankees.  For the most part, it looks like an ordinary transparent-plastic-tube bird feeder, with openings for the birdseed at the bottom and a round wire perch below that for the birds to sit on as they eat—that is, birds who don't weigh as much as your average squirrel.  Because when a squirrel exercises his athletic prowess to climb down the rope that the feeder hangs on and puts his weight on the perch to get in position for a meal, the increased downward force on the perch flips a switch that goes to a battery-powered motor.  And all of a sudden, the squirrel finds himself on a merry-go-round like the one that goes out of control at the end of Hitchcock's "Strangers On a Train." 

For the animal-rights fans among their customer base, the Droll Yankees say their contraption "gently spins squirrels off the perch."  Allain found a clip taken by a satisfied customer of an unusually persistent squirrel, though, and you can view it here to judge whether the word "gently" is appropriate.  I don't think the squirrel suffered any permanent damage, but he probably had a bad case of vertigo for a while.

I have had my own problems with birdseed-thieving squirrels.  Years ago, while we were living in New England, I had my own idea about how to fix the problem.  We bought the same general kind of plastic-tube feeder that Droll Yankees sells, and hung outside our kitchen window.  This one had openings at a couple of levels, and little aluminum rods sticking out beneath the openings for birds to perch on.  Well, the space between the upper and lower rods was just enough for a squirrel to grab onto with his front legs on the upper one and his back legs on the lower one while he stuffed his face with illicit birdfood. 

We tried the usual passive things first.  A conical metal hat kind of thing hung onto the rope above the feeder was supposed to make the squirrel slide off, but he managed to swing inward while falling and catch onto the feeder anyway. 

Looking at those rods one day, I had a thought.  Being an electrical engineer, my thoughts naturally ran along electrical directions, and I recalled how one of Thomas Edison's first (non-patented) inventions was inspired by a roach-infested telegraph office he worked in.  Availing himself of the 150 volts or so that was used to energize long telegraph lines, he rigged up a pair of copper patches along a favorite roach pathway and awaited results.  Sure enough, once the roach completed the circuit, his career was at an end.

I had no desire for fried squirrel meat, so I dug around in the basement until I found a couple of transformers left over from the time a previous owner had installed the only innovative things Ma Bell ever did for consumers in the 1960s:  Princess telephones.  The phones had a little pilot light that ran off a low-power transformer that you plugged in the wall, and though the telephones themselves were long gone, the transformers were still there in the basement. 

The secondary voltage was only 6 volts AC or so, and by running this low-voltage power from one transformer out through a pushbutton switch by the kitchen window and over to the tree and onto the bird feeder, I was not endangering the house with high-voltage wiring.  But on top of the feeder, I placed the second transformer to step the voltage back up to 120, and ran one wire to each of the two poles.  You see the trend of my thoughts now.  The current was only a few milliamps, not enough to damage the squirrel, but enough to get his attention.

This was in the days before cellphone cameras (or cellphones, for that matter), but it brought a glow to my wicked heart to watch the squirrel clamber down along the rope, slide past the cone, and position himself for a nice repast, only to get the surprise of his life when I pushed the button.  He decided it was time to leave, and not by climbing up the rope either. 

The drawback of this system, of course, was that you had to stand at the window and guard the feeder, or else the squirrels would just come back when you weren't watching.  Squirrels don't take to training very well, and so while my system had great entertainment value, it didn't cut down much on the loss of birdseed to squirrels.

I'm out of space, so I will leave you, gentle reader, to ponder the ethical implications of favoring one member of the animal species while tormenting another one with centrifugal force or high voltage.  Here in Texas, we've switched to hummingbird feeders.  The squirrels aren't interested in them.

Sources:  Rhett Allain's article on the DrollYankee centrifugal squirrel-preventing bird feeder (only $200, I might add) can be found on the Wired website at  The video of the persistent squirrel is at
and the Droll Yankees feeder itself can be viewed at  A good description of the climactic merry-go-round scene in Strangers On a Train can be read at

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