You don't see the birds until you get out into the unmowed field.
And even then, you hear them before you see them.
But only if you're listening for small sounds. Grasshopper sparrow sounds like--well, a grasshopper. His song is just a buzzy trill.
This fellow spent half an hour bathing in the morning dew on the flower heads of wild parsnips. He fluttered his wings and rubbed his breast in the flower. Every few seconds he would pause to raise his head and sing.
The bird was a male. You can't tell a grasshopper's gender by appearance, but only the male sings.
and Diane Porter