Loud and beautiful calls

The baby wrens are constantly calling for their parents. "Bubbling musical series of complicated whistled notes and trills" (Cornell) is a good enough description of their songs and calls. The parents are never far away. They sing seemingly in response to babys' calls. Their songs become louder as they approach the nest with food for the babies. It takes only a couple of seconds to feed the baby. As soon as the baby is fed the parent is off again for next round trip.