The Yellow-breasted Bunting Emberiza aureola was once regarded as one of the most abundant passerines in Eurasia. Its global population was estimated to be at least several million birds and its breeding range was expanding westward into Europe prior to the 1980s. The decline was firstly detected when breeding birds in Japan started to decrease in the 1990s. A comprehensive study published in 2015 revealed an 84.3 to 94.7% decline of the population in about three decades.
