At first glance, I didn't catch it, did you? Who is feeding whom in the photo? This outstanding contribution photo from swc capture a mother bird feeding her young. If you have not looked closely, baby birds open their mouths to be fed. The smaller of the two birds is feeding the larger of the two birds. The mother bird is the smaller of the pair. The two birds obviously are not the same and I would have to speculate that another bird laid it's eggs in this mothers nest perhaps?