Droll Yankees Onyx Clever Clean and Fill Finch Magnet Bird Feeder

Excuse my stupidity, but why is this called a magnet feeder? Where is the magnet and how does it work?

Unfortunately, the doves hang on to the perches and quickly empty the bird feeder. Does anyone know how I can modify it to deter the doves?

is perch plastic or metal?

Can this feeder be post-mounted?