Eastern Bluebird Sialia sialis
Flight call description Typically a low, mellow, two-syllabled "pya-der". Less often a shorter, one syllable "pya".
Fig.1. Oklahoma October 12, 1989 (WRE).
Perched bird.
Examples Diurnal
Similar species Usually distinctive. Hermit Thrush is higher and evenly descending. See Mountain Bluebird and thrush-like calls.
Behavior A diurnal migrant but probably begins its migrations well before sunrise. No evidence of nocturnal migration. Calls regularly while perched and in flight during the day.