Birds create sound by forcing air through the syrinx, or voice box, at the lower end of the windpipe. The rushing air produces sound by vibrating membranes lining the syrinx. They adjust the tautness of the membranes to produce higher and lower sounds.

Birds produce a variety of sounds that send messages to birds and other animals. These messages can express alarm, proclaim territory, advertise for a mate, or simply keep each other informed of each others' presence.

Bird calls are short and simple. They range from sounds that beg for food to calls that help locate a mate in a large colony.

• Black-Chinned Hummingbirds
• Whitewing Dove
• Cardinal
• Bullocks Orioles
• Mallard
• Golden Eagle
• Two Great Horned Owls
• hammering Ladder-back woodpecker.
• American Crows
• Glaucous-Wing Gulls

Songs are usually longer and more complex. Most songs are sung by male songbirds during the mating season to attract a mate and defend a territory. Just as we have different voices, no two birds sing exactly alike.

• House Finch male
• Song Sparrow
• Western Meadolark
• Grace's Warbler

Some birds appear to recognize individual bird voices. This may be useful to a male who is able to distinguish between a harmless neighbor and a bird that threatens his territory and for a female to identify her mate.

Songbirds learn their songs from members of their own species. Like most birds, they hatch already knowing less complex calls that are used for communication. Some birds will learn songs only from their own species. Others will accept tutors of another species and learn the "wrong song."

Classroom Activity: Who is calling?