This Collared Dove shows the plumage abnormality of schizochroicism. This is a regressive gene found in females which leads to a pigment defect and renders the overall plumage tones a mixture of white and fawn.
This female bred near my garden in 2003 (with the normal male bird it is paired with in the photo) and reared at least one schizochroic daughter. The daughter's plumage was less marked than the mother, and she too bred here in 2004 rearing another female (now at least a third generation). This youngest addition however had near normal plumage, and it was only when it was alongside a normal bird could you tell that its plumage was slightly paler.
schizochroic Collared Dove Farcet Fen