高海拔山区气候条件恶劣, 资源匮乏, 探究同域分布的近缘物种如何利用有限的资源以实现稳定共存, 对于了解高山生态系统生物多样性格局的形成和维持机制具有重要意义。鸡形目鸟类飞行能力弱, 属于典型的地栖物种, 生态位空间相对狭窄, 可能面临更高的种间竞争压力。本研究旨在比较几种同域分布的鸡形目鸟类的时空生态位, 为了解高山生态系统同域物种的共存机制提供新的研究案例。2020年4-9月, 研究人员在四川卧龙国家级自然保护区海拔3,300-4,200 m的高山区域进行了野外调查, 通过样线法和样方法对鸡形目鸟类群落优势物种绿尾虹雉(Lophophorus lhuysii)、雉鹑(Tetraophasis obscurus)和雪鹑(Lerwa lerwa)繁殖期的微生境进行调查, 使用红外相机对其活动节律进行监测, 并运用核密度估计法从微生境利用和日活动节律两个生态维度进行了种间生态位比较。结果显示, 雪鹑在微生境利用和日活动节律上均与其他两个物种存在显著差异。绿尾虹雉与雉鹑在微生境的利用上具有相似偏好; 但绿尾虹雉的早活动高峰晚于雉鹑, 晚活动高峰早于雉鹑, 表现出显著的种间日活动节律差异; 然而, 整合两个维度后, 绿尾虹雉和雉鹑的整体生态位仍然高度重叠, 没有显著分化。本研究表明高山鸡形目物种间的生态位分化体现于多个不同的生态维度, 并且不同物种之间的分化方式有所差异。在空间和时间生态位上的显著分化使雪鹑与同域物种间的竞争压力相对较小, 有利于其实现稳定共存。而绿尾虹雉与雉鹑的整体生态位高度重叠, 建议进一步对其食性开展研究, 探讨营养生态位上的潜在种间分化。

Aims: Generally, mountainous areas in high altitudes have harsh climate conditions and a lack of resources. It is important to understand the formation and maintenance mechanisms of biodiversity patterns in alpine ecosystems by exploring how closely related species that are sympatric use limited resources to achieve stable coexistence. Galliformes are typical ground-dwelling species with weak flight and dispersal abilities, and face higher interspecific competition pressure due to relatively narrower niches. Our study aims to compare the temporal and spatial niches of sympatric Galliformes species, and to provide a new case study for understanding the coexistence mechanism of sympatric species in alpine ecosystems.
Methods: From April to September 2020, field surveys were conducted in an alpine ecosystem at an altitude of 3,300-4,200 m in the Wolong National Nature Reserve, Sichuan Province. We used a transect survey design to investigate the microhabitats of the Chinese monal (Lophophorus lhuysii), chestnut-throated partridge (Tetraophasis obscurus), and snow partridge (Lerwa lerwa) who dominate the alpine Galliformes community and monitored their activity by infrared camera traps. Their ecological niches were compared along the two dimensions of microhabitat utilization and daily activity rhythm by using the kernel density estimation method.
Results: The results indicated that there were significant differences in both microhabitat utilization and daily activity rhythm between the snow partridge and the other two species. The Chinese monal and chestnut-throated partridge have similar preference in microhabitat utilization; the morning activity peaks of Chinese monal were later than those of chestnut-throated partridge, while its evening activity peaks were earlier than those of chestnut-throated partridge, demonstrating significant interspecific differences in daily activity rhythm; however, their overall niche integrating the two dimensions still highly overlaps without significant differentiation.
Conclusion: Our study reveals that niche differentiation among sympatric alpine Galliformes species is reflected along multiple ecological dimensions, and differentiation patterns vary between different species. The significant differentiation of the snow partridge in spatial and temporal niches is likely makes it less competitive with sympatric species, which is beneficial to its stable coexistence within the community. The overall niches of the Chinese monal and chestnut-throated partridge overlaps greatly. Therefore, it is recommended that further studies be conducted on their feeding habits and to explore the potential interspecific differentiation in trophic niches.