Greater prairie-chicken. View of a male greater prairie-chicken (Tympanuchus cupido) displaying on his lek, or displaying patch. Greater prairie- chickens live in grassland and sparse woodland in North America, although destruction of their habitat has severely reduced their numbers. The large orange sacs seen on the side of this bird's head are inflated during the courtship display. Greater prairie-chickens may grow to a length of almost 50 centimetres. Photographed in eastern Colorado, USA.