In Victorian London anyone could buy a caged skylark for a few pence. The birds were caught in the wild and sold with a patch of turf lining the bottom of the cage to make them feel at home. Often the birds would try to fly upwards, as they would in the wild, and they would beat themselves against the top of the cage. Pining for their freedom, the birds wouldn’t last long. But there were plenty more. 

John Muir, a Scotsman and by some, considered to be the founder of the nature conservation movement in the USA, kept caged skylarks as a child, until he realised the cruelty he was inflicting.