Dawn Chorus

I went out early this morning to soak in the orchestration of the ‘dawn chorus’. This term refers to the combined songs of many birds in the first hour of light. The reason for the intensity of the music is the desire of male birds to defend their territorial claim over a patch of feeding, breeding or nesting space, as well as to attract a mate to that space by proving their vitality through the strength of their song. Females may vocalize at this time as well, letting males know of their presence and locations. Sound also travels best at dawn and there is less competition from other non-avian noise.

Two birds heard from my doorstep in the dawn hour are Wrentit and Bewick’s Wren. The competing songs of these two different species has been the subject of study. According to Gareth Hew Davies “they manage to alternate their singing bouts so that they are never in direct conflict. The Bewick's wren starts the session in the morning and dominates the airways for the first hour. The wrentit stays quiet to avoid competition, but gets his turn to sing in the second hour, after which the Bewick's wren starts again. And so this astonishing sharing of the stage goes on”.

Fans of the morning bird chorus, especially in the U.K. join organized dawn chorus walks, sometimes beginning as early as 4 am so they can catch the first songs of the new day. International Dawn Chorus day is held on the first Sunday in May in England. In areas of human-caused bird decline (introduction of predators, competitors and conversion of natural habitats to homes) the dawn chorus is noticeably diminished.

Students of bird song hypothesize that species with larger eyes begin vocalizing first as their eyes perceive the lightening sky before their smaller eyed cousins.

For more on Bird Song visit http://www.pbs.org/lifeofbirds/songs/index.html