|
The Dawn Chorus
Most birds show an increase in song activity the hour before and after sunrise. Birds of different species sing during this time of day to defend their territories, attract a mate, and possibly for other unidentified reasons. The musical composition that these birds collectively make is called the Dawn Chorus. Two popular theories as to why so many birds choose this time to sing include: 1) Sound carries better in the calm cool morning air than at other times of the day, and 2) It is still too dark to forage on insects (most of which are not out flying yet) so birds sing until they can see their prey.
We recorded the Dawn Chorus on a private tract of land near Condon, Montana. We rotated a wireless recording device through six different recording sites in two different habitats (open canopy marsh and closed canopy forest), moving the device once a week. The recording started in mid-April 2009 and continued throughout the summer (view a calendar of bird detections).
We also used HOBO Pendent Light Meters that we moved with the microphone to compare the available light to the start times of each species. The data were processed on a daily basis and stored in a database accessible on our website. Sound clips of individual birds were extracted from the recordings if they provided good examples of a species' sound. This list provides links to the archived sound recordings.
|
