Abstract: Crossoptilon auritum is a bird distributed in high-altitude forests and shrublands of the central and western China. In this study, we used MaxEnt model to predict the geographical distribution of C. auritum in China and examined environmental factors driving its distribution, based on 158 presence points and 12 environmental factors. The results showed that the suitable habitat area of C. auritum was 2.23×10⁵ km² in China, which was mainly distributed at the junction of Sichuan, Qinghai and Gansu provinces and spread out in all directions. The sub-suitable habitat area was 3.13×10⁵ km², concentrated in the periphery of suitable habitats. The main environmental factors and optimum ranges of habitat suitability for C. auritum were altitude (2000-3800 m), mean temperature of the warmest quarter (9-18 ℃), isothermality (30%-38%) and vegetation types (coniferous-broadleaf mixed forests, coniferous forests, and shrublands). Results of the Jackknife test showed that the AUC (area under curve) value of altitude and its gain was the highest, which was one of the most important environmental factors affecting the habitat suitability of C. auritum. Our findings provide scientific basis for further clarifying the geographical distribution of C. auritum in China and formulating effective conservation strategies.

Key words: Crossoptilon auritum, MaxEnt model, habitat suitability, environmental factor, geographical distribution pattern.