It is 4:50 am on May 28, 2010. It is still dark and I am standing in the woods in front of my home in Berkeley Co., WV. I am directly under a tree where I heard a supremely talented singer give his lovely dawn performance several days earlier. I wait patiently, anticipating that he will return to the same perch. Off in the distance, I hear him begin whistling his sweet and plaintive songs, slowly at first: pee-a-wee . . . wee-ooo . . . pee-a-wee . . . weee-oh. Then he falls silent. I worry that I am in the wrong place. Suddenly, as if out of nowhere, he sounds off right above me, no more than 40 feet away. I am elated. Within a minute, he is singing full-tilt, delivering three different song phrases in a fairly stereotyped order, with only a brief pauses between: ah-di-dee, pee-a-wee, ah-di-dee, weee-oh, ah-di-dee, pee-a-wee, ah-di-dee, weee-oh and so forth.

This is the Eastern Wood-Pewee’s “dawn song,” more widely referred to as “twilight song” in the literature. The function of this delicately beautiful display is not clearly understood. In this particular twilight performance, the male sings three different song phrases with only a second’s pause between (around 25-30 songs per minute). Later in the day, the same male will sing only two song phrases (pee-a-wee and weee-oh) at a much more leisurely pace, with five or ten seconds pause between each song (question: have you figured out why they call this bird a “pewee”?).

Here are a few minutes of the 10-minute performance given by “my” pewee as he sang from a dead twig high in a tree as the sky began to lighten:

Eastern Wood Pewee Twilight Song. May 28, 2010. Berkeley Co., WV. ©Wil Hershberger.

Lang Elliott also captured a pleasing example of pewee twilight song at dawn on May 19, 2010, at Land Between the Lakes, Kentucky. Note that Lang’s bird typically sings his three different song types in a slightly different order than “my” pewee:

Eastern Wood Pewee singing twilight song at dawn. Recorded by Lang Elliott on May 19, 2010 at Land Between the Lakes, Kentucky.

While he is pouring forth his wonderful aria, the male pewee rarely sings the same song phrase twice in a row (unless he is distracted by a tasty insect morsel). Furthermore, each male tends to sing his different song phrases in a particular sequence. In his book “The Singing Life of Birds,” ornithologist Don Kroodsma wrote about the twilight song of a pewee that lived in his yard. Don’s male sang four different song phrases (rather than the usual three) and during the time of study never repeated a particular phrase twice in a row. Amazing!

We may never know what is really behind this amazing behavior. Is the male simply re-asserting his claim to his territory and making certain that all neighboring males (and females, including his mate) know that he has survived the night and is alive and well? Is his Herculean effort aimed primarily at females, informing them that he is a very fit and talented male with terrific genes to pass on to another generation? Or is he singing for the sheer joy of it, indulging himself with a spectacular musical performance in the safety of the darkness before dawn?

Wallace Craig and The Musicality of the Pewee’s Twilight Song:

Amazingly, the twilight song of the wood-pewee was not described until 1926, when ethologist Wallace Craig published a paper describing the phenomenon:

click to see whole page

While the wood-pewee’s twilight performance is not particularly complex, it is undeniabliy musical to the ear. It is both sweet and plaintive, simple yet exquisite, mournful yet pleasing to the ear. Craig studied the delivery sequence of the three song types and noted that the down-slurred weee-oh functions like a musical finale, marking the end of a unified series of song phrases.

We humans can hear this and feel it emotionally. Listen carefully to either of the above recordings and note how the alternation of pee-a-wee and ah-di-dee phrases give one a sense of endless repetition of the theme . . . but when a weee-oh finally comes along, the mind sighs with pleasure and there is a strong sense of closure (even though the performance begins afresh without pause). Listen with your heart and you will understand the musical significance of the pewee’s down-slurred weee-oh:

pee-a-wee, ah-di-dee, pee-a-wee, ah-di-dee, weee-oh (sigh)

Note: this blog post is a collaboration between Wil Hershberger and Lang Elliott