Photo By Mark Wick. Most adult loons also start growing new body feathers before they migrate, but they keep their wing and tail feathers until after they reach the ocean. Loon body feathers have to be dense enough so water can't seep through them and thick enough to hold the loon's body warmth. By January, even though the chicks' bodies have stopped growing, both this year's baby loons and all the adult loons will already be growing a whole new set of feathers. During the time the loon wears a feather, the tip wears off and the feather may bend or break.
Feathers also fade in light.
Since loons spend their entire lives either flying in the sky, swimming in open water, or sitting at the water's edge, they hardly ever get to hide in the shade. Cut a bright piece of construction paper into three equal strips. Put one strip in a dark drawer or desk. Tape the other two to the indoor side of a sunny window. Take one strip down after a day and compare it to the strip in the dark drawer.