The Tweek

Radio Cuba, Havana, Cuba

At the tone, three hours, fifty-three minutes, Coordinated Universal Time

What is the difference, the distinction, between a swish and a whistler?

Well, a swish descends through the audio frequency spectrum with time
Whereas a whistler is more coherent

In other words, the whistler is a rarified and specialized case of the swish

Well, we find some which start out like a swish and end up like a whistler
And we call these "swishlers"

They're audio frequencies, but they're not audible unless you have radio ears

That's correct. They're audio frequency radio waves

We've talked about whistlers a lot
Now perhaps we should just devote no more than
A minute or two to the tweek

The tweek is rather well understood
I demonstrate that these are indeed tweeks
But that the rate of decline in tone is so fast
That they're not recognizable as well-developed tweeks until you slow them down

A mature tweek is one that's many miles away

If it's a crash or a bonk, and if it's far enough away
So that it's not that but not a tweek
It's one of these immature tweeks

The dawn chorus, on the other hand, is not at all well understood
And there is no theory to explain it