The merlin (Falco aesalon) is the smallest of the British falcons, and is found as a breeding species in Wales and the northern parts of England, Scotland and Ireland. It preys chiefly on small song-birds. The total length is 27 cm. The male is coloured slatey blue, with the nape and under parts rufous, and the whole body streaked with brown. In the female the under surface is white, and the rest of the body dark brown, the tail being crossed by light bands. Research Merlin