Robert William Service - Captivity

O meadow lark, so wild and free,
It cannot be, it cannot be,
That men to merchandise your spell
Do close you in a wicker hell!

O hedgerow thrush so mad with glee,
it cannot be, it cannot be,
They rape you from your hawthorn foam
To make a cell of steel your home!

O blackbird in the orchard tree,
In cannot be, it cannot be,
That devils in a narrow cage
Would prison your melodic rage!

O you who live for liberty,
Can you believe that it can be,
That we of freedom's faith destroy
In dungeons, innocence and joy?

O decent folk who read this page,
If you should own a bird in cage,
Throw wide the door, - God gave it wings:
Then hear how in your heart it sings!

Robert William Service

http://www.poemhunter.com/poem/captivity/