Occasional Mimicry and Night-time Singing by the Western Curve-billed Thrasher (Toxostoma curvirostre palmeri)

The first instance of vocal mimicry is reported for the western subspecies of Curve-billed Thrasher (Toxostoma curvirostre palmeri). A Curve-billed Thrasher engaged in countersinging with a migrating Black-headed Grosbeak (Pheucticus melanocephalus) near Tucson, Arizona. Night-time singing by Curve-billed Thrasher is also documented for the first time. At least three responding Curve-billed Thrashers engaged in spontaneous song near Tucson, Arizona. Additional night-time singing was elicited by playback recordings