The nickname for the smallest PAR Can
American DJ P16A SPECIAL Par 16 Mini Can, Silver, with Lamp | Full Compass
"Birdie" in common usage is any can that will accept either a PAR16 or MR16
lamp. A variety of socket
types are available including but not limited to E26/27 screw, GU10 and GX5.3 2-pin. The two most common voltages are 12V and 120V.
The definition is sometimes extended to PAR20 cans as well.