Bye+Bye+Birdie

This line says:

A bird for treason - in the pound

This line made me ask myself, "Why would a bird be locked up for treason? And more so why in a pound? When I think of a pound I think of a place where unclaimed animals are sent to their own personal death row. If no one comes to find them, thats the end. The older the animal is, the sooner it gets to die. Birds normally are not found so commonly in pounds, and can a bird really commit treason? These questions I do not have an answer to currently. Sometimes a bird is referred to someone who snitches, who tells secrets. A bird is also a lightweight. Miners use birds to see if its safe to enter the mines. They send a canary down and if it stops singing, they know not to enter. They are used for that purpose and then that leads to their own death.

http://en.wikipedia.org/wiki/Animal_shelter