Common loon calls are captivating and memory-stirring for those of us who have spent time among the pines, firs, birches and crystal waters of the north. What would our northern lakes be without the mournful cry and laughter of the wilderness? To appreciate loon calls, you simply have to hear them in their natural setting. And as we listen, the variations of yodel, tremolo, wail and other calls can tell us much about loon behavior.
The yodel call, "oo-AH-ho," is used for territory advertisement and defense. It is given only by the male. The far-carrying wail call, "ahaa-ooo-oooo-oooo-ooo-ahhh," is frequently used and helps the pair keep in contact with each other. This call is often heard at night and is considered the mournful cry of the wilderness.
The tremolo call, a wild laugh, probably is the loon's all-purpose call and can signal alarm, worry or greeting. Usually the tremolo is coupled with a behavioral response such as a dive, a run on the water surface or a take off, and it's the only call loons can give while in flight. The presence of people often evokes the tremolo, especially when boaters approach too closely.
But we must remember, the tremolo isn't reserved only for intruding humans. Millions of years before people appeared, the tremolo call echoed across ancient lakes. Loon pairs frequently use a tremolo duet when something threatens their young. This splendid tremolo duet also is used in spring to reinforce pair bonds and to advertise territorial rights.
