The Red-headed Bunting breeds in Central Asia and winters in India. In Hong Kong it is a rare winter visitor; females and young can be difficult to identify because they resemble Black-headed Buntings.
The Hong Kong account says females and young resemble Black-headed Buntings but have less distinct crown streaking and more distinct back streaking. In winter, brown feather tips obscure the male's red head.
Researchers studied male Red-headed Buntings kept on short-day schedules in individual cages. For six weeks, groups received about 2 lux of artificial light for four hours at different points in the night, or throughout the night; a control group stayed in darkness. The birds’ responses varied with timing, including nighttime activity and changes in daily body rhythms.
Light in the middle of the night produced the strongest migration- and breeding-related responses, similar to all-night light. Early-night light extended activity after dusk, while late-night light advanced morning activity. The experiment shows how the same dim light can affect a migratory bird differently depending on when it appears.
An extinction-risk assessment has not been added yet.
In this experiment, a four-hour light period in the middle of the night caused stronger migration- and breeding-related responses than light earlier or later in the night. The authors note that part-night lighting could help reduce artificial light’s physiological effects on nocturnal migrants.