Before you thought of spring

Before you thought of spring,
Except as a surmise,
You see, God bless his suddenness,
A fellow in the skies
Of independent hues,
A little weather-worn,
Inspiriting habiliments
Of indigo and brown.

With specimens of song,
As if for you to choose,
Discretion in the interval,
With gay delays he goes
To some superior tree
Without a single leaf,
And shouts for joy to nobody
But his seraphic self!