How many notes in a Whip-poor-will's song?

When a Whip-poor-will sings its song, repeating its onomatopoeic name, how many notes do you hear?

Whip. Poor. Will. ??

No, not three.

Other Whip-poor-wills, probably other birds, hear five notes. You would need bird ears or sophisticated recording equipment to do the same. (There are examples on the Internet.)

Author Simon Barnes explains this in his new book, "The Meaning of Birds."

Barnes records bird songs, then plays them back at a slower speed. His point is to hear the individual notes in a song. Whip-poor-will does not sing a three-note song. The song of a House Wren is far more complex than we hear in its rapid delivery.

I don't have the required sound equipment for that demo. I did it the old-fashioned way. I played the songs on my iPhone and recorded them in the slow-motion of my iPad. Try it. Doesn't sound at all like bird song, that's for sure. It resembles whale songs. But the complexity sung by the bird is there.

Birds are flyers because certain dinosaurs developed feathers as thermo-insulation. More and more feathers became an aid in running, leading to soaring leaps, leading to flying. We have more than 10,000 bird species, about 40 of which do not fly.

We are bird watchers, not mammal watchers, he writes, because the former are ubiquitous, colorful, vocal, all the things that mammals are not.

Colorful? Barnes suggests that the birds we call most colorful often are those we see least often, chosen because they are brilliant surprises. Barnes believes the most spectacular bird is our common male Mallard. "A riot of color," he writes, "absolutely over the top."

Look closely at this duck, linger, he suggests. Barnes believes we don't see the colors because we overlook them. We know this duck at a glance. A lingering look is not necessary, so we miss the beauty Barnes sees in a definitive look.

He writes that birds are the origin of our music. They provided melody. We added rhythm. He puts bird sounds into two categories — contact calls, often given as warnings, and songs.

He writes about chickens, the most numerous birds in the world, descent of the Red Jungle-fowl. Why them? He speculates that those birds were lured to their nugget future by our meal scraps and handouts. Freedom sold for a free lunch.

A review in a British magazine calls this book "a wise and witty celebration of birds." It is that, indeed.