dawn choruses

Noun

dawn chorus (plural dawn choruses)

1. Birdsong by a large number of birds occurring in the early morning.
   • But the music of the spring-tide is past; the cuckoo is no longer vocal; the dawn-chorus is silent; summer has stilled the voices that but lately trilled so tirelessly, and, until another spring arrives, hedgerow and spinney will not again resound with the singing of the birds.1898 August 27, S. W. F., “July in South Devon”, in The Garden: An Illustrated Weekly Journal of Horticulture in All Its Branches, volume LIV, number 1397, London, →OCLC, page 160, column 2

   Synonyms:

   dawn choir

2. Radio interference sometimes experienced at sunrise.
   • [T]he dawn chorus usually has a characteristic chirpy sound, but at times changes into a hiss not unlike tube noise. […] Several investigators, including the author, have at times noticed a tendency for the dawn chorus to change intensity for a short period immediately following some lightning...1956 September 14, Harold E. Dinger, “The Dawn Chorus”, in Whistling Atmospherics (NRL Report; 4825), Washington, D.C.: Naval Research Laboratory, →OCLC, page 14

   Synonyms:

   chorus