||The lunar cycle is known to affect the behaviour of strictly nocturnal species, but for diurnal species that are periodically active during the night, this has been less investigated. Nocturnal bird song is relatively common in diurnal species, yet research on this behaviour accounts for little of the research on avian vocalisations. This is surprising given that diurnal species are adapted for bright environments and therefore may be particularly sensitive to change in the lunar cycles. We used automated bioacoustic recorders and automatic song detection software to measure nocturnal song rate in a diurnal bird where both sexes sing, the willie wagtail (Rhipidura leucophrys). We deployed recorders at eight locations across four naturally dark sites resulting in 457 h of nocturnal audio. We confirmed anecdotal evidence suggesting that willie wagtails are prolific nocturnal singers during the breeding season and demonstrate that while both male and females sing during the day, nocturnal song is largely sung by males. Moreover, we show that nocturnal song increased with lunar illumination, contrasting with previous research on other diurnal species that sing at night. Our data allow us to hypothesise possible functions for nocturnal song in this species, such as territory defence or mate attraction.