The birds are eager to sing, as the flowers to bloom.

April 4. 

Wednesday morning. 

Lodged at Sanborn's last night after his rescue, he being away. 

It is warmer, an April-like morning after two colder and windy days, threatening a moist or more or less showery day, which followed. 

The birds sing quite numerously at sunrise about the villages, - robins, tree sparrows, and methinks I heard the purple finch. The birds are eager to sing, as the flowers to bloom, after raw weather has held them in check.

H. D. Thoreau, Journal, April 4, 1860

The birds sing quite numerously at sunrise about the villages. See April 4, 1855 ("A fine morning, still and bright, with smooth water and singing of song and tree sparrows and some blackbirds. "). See also March 12, 1854 ("All these birds do their warbling especially in the still, sunny hour after sunrise, as rivers twinkle at their sources"); April 1, 1854 ("The birds sing this warm, showery day after a fortnight's cold with a universal burst and flood of melody."); April 2, 1852 (“The air is full of the notes of birds, - song sparrows, red-wings, robins (singing a strain), bluebirds, - and I hear also a lark, - as if all the earth had burst forth into song.”); April 15, 1859 ("We are provided with singing birds and with ears to hear them.  . . . Whether a man's work be hard or easy, whether he be happy or unhappy, a bird is appointed to sing to a man while he is at his work. ");  April 16, 1855 ("The robins, etc., blackbirds, song sparrows sing now on all hands just before sunrise, perhaps quite as generally as at any season.")