When I was volunteer at a lighthouse we had the problem of sea gulls staying on the structure, and poop was definitely an issue.

The solution was to actually use electricity to shock them away from their favorite landing places.

I really don't know why so many people thing this cannot work.

Here is one source I found on the interwebs after a short search.

 

Just took a photo of a brown headed cowbird today...

 

I really don't know why so many people thing this cannot work.

9V is not sufficient energy and a single hot line typically does not provide sufficient differential potential. A grounded perch bar with an insulation strip atop it and then a sufficient energy hot wire on top of that so that when the bird perches and wraps his feet around both the hot and ground may work if the voltage was high enough. Such as that produced by a pulsing hi voltage electric fence charger. Personally, I'd opt for a BB gun... But unless you post an all-day watch the results will probably come to naught. A properly designed bird feeder that excludes larger birds is a better solution. Blue Jays and even Cardinals are notorious for emptying a feeder by raking the seed out to find that just right morsel of seed.

 

Your 9V battery is not going to shock a bird or anything else.

 

Just took a photo of a brown headed cowbird today...
View attachment 237125

There's the culprit

 

Just took a photo of a brown headed cowbird today...

.....

There's the culprit

Dont worry I'll get em out of here.

 

I'm trying to wire my bird feeder so I can send a small jolt to a perch of my choice

Instead of trying to shock the birds why not a circuit that would scare the birds.
Are you planning on operating the shock circuit manually as you watch when a cowbird lands on a feeder?

 

Build a feeder that allows you to cut off access to the seeds when the cowbird arrives, or sound an air horn when a cowbird arrives, or sprays bird-b-gone when the cowbird arrives, or plays a cowbird mating call on the opposite side of your yard.

 

I really don't know why so many people thing this cannot work.

The concept can work. Just not at 9V. {unwatching}

 

As noted by several, the birds won't get a shock since there is not a complete circuit path.
Running the hot wire to one half of the perch and the other (common) wire to the other half of the perch may work.
A 9V battery is safe but won't have any effect since it creates no shock (have you never touched the terminals of a 9V battery?).
It takes about 50V before you can even feel it.

You need an electric fence controller, such as they sell for farm animal control, which puts out safe, periodic high voltage pulses.

Use that fence controller with the "ground" side being a sheetmetal floor where the bird stand. The "fence " portion can be a bare wire above at a height that the larger birds will contact but the smaller birds will not contact.
And instead of a standard fence charger just use an automotive ignition coil connected to the floor and that wire. Then your push button can switch on a 6 volt battery to the ignition coil primary. It will deliver one pulse each press and release.

And there is nothing wrong with killing those cow birds! They are nasty creatures that kill any of the smaller and nicer birds with their nasty tricks. Just be sure to dispose of the dead ones properly.