Mistletoe-eating Thrush The mistle thrush is around 28 centimetres in length and is the biggest species of thrush found in the United Kingdom. It has a long tail, upperparts that are a brownish-gray colour, and a white belly that is spotted heavily in a dark brown colour. The colour of its legs might be described as a yellowish-brown. This bird should not be mistaken with the song thrush, which is somewhat smaller and has warmer brown tones in its plumage.