关键词: 黄胸鹀, 濒危物种, 最大熵模型, 分布区萎缩

Abstract: The yellow-breasted bunting (Emberiza aureola) is a songbird that was once widely distributed across Eurasia. In recent years, its conservation status has continuously risen, and it has become a globally “Critically Endangered” species. In China, it is listed as a National First-Class Key Protected Wild Animal. In recent years, the yellow-breasted bunting has experienced a dramatic decline, which was once attributed to the illegal hunting in eastern China. However, the potential influence of climatic factors on the yellow-breasted bunting population in the breeding areas has been neglected. In this study, we applied the theory of climatic ecological niche by combining climatic variables and distribution points in the breeding areas of yellow-breasted buntings. This approach allowed us to predict, based on the Maximum Entropy Model (MaxEnt), the potential breeding area suitable for yellowbreasted buntings in the present period, as well as the trend of suitable areas in two future periods, the 2050s and 2070s, under the backdrop of climate change. The results showed that: (1) The main variables affecting the distribution of the breeding area of the yellowbreasted bunting were the rainfall in the warmest season (a contribution rate of 35.4%), the mean annual air temperature (a contribution rate of 35.3%), and the coefficient of seasonal variation of temperature (a contribution rate of 12.4%). (2) The total area of suitable breeding areas in the current period is 11.3118 million km², mainly distributed in Russia (77.93%), followed by China (10.52%), Mongolia (5.30%), Finland (3.22%), and other countries such as Sweden (3.03%). (3) Under the background of future climate change, the area of suitable breeding grounds will continue to shrink. Compared with the current period, the suitable area will decrease by 15.50% in the 2050s and 32.99% in the 2070s. Among them, China will see a significant reduction in suitable breeding areas, with a decline of 79.22% in the 2050s and 91.39% in the 2070s. (4) The centroid of the breeding range is shifting northeastward. The suitable area is shifting towards higher latitudes, while that in the low-latitude areas is shrinking, with contraction in western part of Europe and expansion in Northeastern Asia. Our results suggest that climate change poses a significant threat to the yellow-breasted bunting. Hunting bans alone are insufficient for the conservation and management of this species. Global efforts to curb warming are essential to mitigate the negative impacts of climate change on endangered species.

Key words: Emberiza aureola, endangered species, maximum entropy model, range contraction