Dawn chorus

Dawn chorus. Many birds sing in the early morning, but they don't all start at the same time. According to a study published online the week of 16 January in Proceedings of the Royal Society: B, the reason has to do with when they see the light. The lower birds are in foliage, and thus the longer it takes the sun to penetrate, the later they start chirping. And the bigger a bird's eyes, the earlier it joins in. The function of the dawn chorus is still a mystery, but the leading theory is that the birds are taking advantage of the fact that song travels farther in the cooler, less turbulent air conditions