T&L Publications

I'm thinking of making electric fence charger from an old microwave trans former, I need some ideas, the black bears are getting to bold to get into my beeyard. thanks.

There's more to a fence charger than a simple transformer. Before going into this, look at and understand, fence charger specs and the voltage and current. They also pulse the output.
If you are in a shooter friendly area, make a device that fires powder-only shotgun shells at different intervals like is used to scare away birds near airports.
BTW:
A center primed round can be fired with high current going through the primer...
Military aircraft used that method to time the rounds more precisely.

Sure glad I don't underwrite your homeowner's insurance....

Microwave transformers are very lethal and once they draw an arc, they will consume very high current and trip a breaker and most likely set things on fire.. you want something that is low current, and lower voltage.
If you are too cheap to buy a fence charger, and want to build your own, use something safer than a MOT. Perhaps a Ignition coil from a car, you'd have to build a driver circuit. I seen an old antique unit long ago, it used a 6v car battery, It had a slightly off balance beam inside. the heavy side would drift down and hit a contact, and then it would activate a coil to pull the beam back up, and that would fire the coil..it did this about every second or so.
and the coil inside was a ignition coil. the whole set up would run for months on a 6v tractor battery.
Another thing you have to consider, if the birds land on a wire, they won't be effected unless they touch Ground.
birds sit on power lines all day..