The term 'Old World Blackbird' refers to three species of birds: the Merl (4 letters), Merle (5 letters) and OUSEL (5 letters). The Merl is a small blackbird found in Europe, North Africa and western Asia. The Merle is a larger blackbird found in Europe, North Africa and western Asia. The OUSEL is a blackbird found in the British Isles. All three species are known for their melodious song and are popular with birdwatchers.