The Capercaillie (Tetrao urogallus), also known as the Wood Grouse or more specifically Western Capercaillie is the largest member of the grouse family, reaching over 100 cm in length and 4 kg in weight. Found across northern Europe and Asia, it is renowned for its mating display.
Also spelt Capercailzie (the "z" letter representing a yogh) , this species' name is derived from the Gaelic capull coille, meaning "horse of the woods".