Yo! Whose Yodel is That?

Like your own voice, the yodel call of a male loon is one of a kind. Research by Dr. Charles Walcott of Cornell University has verified that each loon male's yodel is a distinctive "voice print" that stays the same while the loon is on breeding territory. But there's more. Preliminary data indicate that a male's yodel might change substantially if that loon is chased off its territory by another male loon and forced to move elsewhere. How common is that? Researchers will try to record yodels from as many displaced males as possible in hopes of finding the answer.

Hear Three Yodels
Dr. Walter Piper, a researcher on the project, sent us some recordings of yodeling loons.Try your ear at distinguishing the yodels of three different males from three different lakes. It takes several minutes to download each file, but once they're downloaded you can play them repeatedly to listen for the differences.

Dr. Walter Piper's recordings of
3 different male loons' yodels
Be patient--these are big files!

Call #1
Click to hear call

Call #2
Click to hear call

Call #3
Click to hear call

See Three Yodels
When scientists analyze sounds, they can use more than their ears. Sometimes they also study a picture of the sound, called a sonogram. This picture is actually a graph, showing the frequencies of the sounds on the Y-axis and time on the X-axis. Using sonagrams is very tricky, and some people never quite master it. You be the scientist! Listen to the loon recordings and follow their sonagrams. Can you HEAR the differences in the calls? Can you SEE the differences? Give yourself some practice; it's not easy!

Call #1

Call #2

Call #3


Dr. Piper can distinguish each of these three male loons by their calls. But what if loons really do make different yodels when forced to change territories? If this really happens, learning how to recognize males with vocal tagging is not likely to be very useful in the long run. Dr. Piper will keep us informed.