Are you surprised that songbirds, including robins, can sing or send warning calls, even with a full beak? It's all thanks to a divided voice box, or syrinx, that sits deep in their chest. Songbirds manipulate muscles to tighten or loosen the sides of the syrinx and pass air through them to make their sounds. Since their songs are formed in their chest, songbirds can sing or call even while carrying food or nesting material in their beak.
"Saw a robin bringing nesting material to a spruce tree in our front yard while her mate chased away other robins." Suzanne in Winnipeg, MB, Canada (April 26, 2014)
Photo: Angela Koehler
