Acadian Flycatcher (Empidonax virescens)
Song: A quick explosive two-syllable peet zah, variously transliterated as spit chee, ha zeep, a KEET, etc... Some authors describe the first syllable as being accented, others claim it is the second syllable. Both syllables are given at equal volume but the second is higher pitched and ends with a distinctly percussive note.
Acadian Flycatcher song, September 5, 2009, Emma Carlin Trail, South Kettle Morraine, Waukesha County, WI.
Females also sing in certain situations, such as in response to her mate's song or to disturbance or threats to the nest (Kellner 1988).
Dawn Song: This song, performed in the hour before dawn, typically consists of the normal territorial song alternating with a variable series of notes that are similar to the first syllable of the normal song. The last note of this series often runs together with the normal song to create a 3-note variant.
Acadian Flycatcher Dawn Song, July 10, 2010. Kettle Moraine South, Waukesha County, WI.
Usually the rate of singing is extremely rapid and prolonged. The dawn song is also sometimes accompanied by a wing twitching display, although this may be very difficult to observe in the pre-dawn hour (Mumford 1964)
Kellner, C. J. and G. Ritchison. 1988. Possible functions of singing by female Acadian Flycatchers (Empidonax virescens). J. Field Ornithol. 59:55-59.
Mumford, Russell E. 1964. The Breeding Biology of the Acadian Flycatcher. Miscellaneous Publications, Museum of Zoology, University of Michigan, No. 125.