A lark mirror, known in French as le miroir à alouettes, was a tool to help hunters entice small songbirds to their location so they could be harvested.
In 1680, an early French dictionary referred to these mirrors for catching larks and ortolans. It defined them as:
A piece of wood carved into an arch where there are several notches which small mirrors are glued & which is supported by a peg in the middle of which there is a hole to put a string in order to make this mirror turn, that is driven into the ground between two sheets to catch ortolans & mainly larks.
These small songbirds were considered to be a delicacy and were cooked and eaten whole, in one large bite; head, bones and all. Ortolans were the most coveted and eating them has been represented in paintings and media over the centuries as a gluttonous, almost shameful act. Modern, French preparation of this delicacy would make the use of ortolans that were captured alive and blinded or kept in dark cages where they were force fed until they were twice their normal size. They were then drowned and roasted in Armagnac, a type of Brandy from the Armagnac region in southwest France.