Grasslands are among the world’s most threatened ecosystems, and steppe birds face increasing risks from human activities. This study investigates how human impacts affect the distribution and community structure of breeding steppe birds in Inner Mongolia, a biodiversity hotspot in Asia. We conducted standardized point-count surveys across a gradient from intact grasslands to urbanized areas, integrating species occurrence data, functional traits and the Human Footprint Index (HFI). Using Generalized Linear Models (GLMs) and Conditional Random Fields (CRFs), we assessed trait-environment interactions and shifts in species associations. Our results indicate that the HFI significantly affects bird communities. Habitat specialists, such as Mongolian Lark (Melanocorypha mongolica), showed negative responses, whereas generalists like Eurasian Tree Sparrow (Passer montanus) thrived in disturbed areas. Trait-based analysis showed that species with larger body mass and specialized diets were negatively associated with HFI, whereas those linked to human-modified habitats exhibiting strong positive associations. In areas with high human footprint, co-occurrence networks grew more polarized: specialists faced intensified competition, while species with positive HFI responses formed stronger positive associations. CRF models indicated that human activities restructure species interactions, favoring generalists and simplifying community dynamics. These findings highlight the dual role of human impact in supporting some species while threatening specialists, potentially driving biotic homogenization. Our study emphasizes the need for conservation strategies that protect vulnerable species and manage those that thrive in human-altered environments. By linking traits and interactions to human impacts, this study provides a framework for identifying at-risk species and guiding conservation in the Anthropocene.

Habitat fragmentation poses a significant threat to bird communities, especially those in open and semi-open ecosystems such as steppes. This study investigates how steppe birds adapt to and utilize fragmented habitats by combining niche modeling with ecological trait analysis. We conducted standardized point surveys to examine the habitat preferences of 32 bird species in Inner Mongolia, China, and quantified their habitat niche parameters using the Outlying Mean Index (OMI). Our results reveal distinct habitat preferences among species, with some thriving in intact environments while others are better adapted to fragmented areas. Grassland species showed high specialization along the fragmentation gradient, while others exhibited adaptability to varying levels of fragmentation. Using a Generalized Additive Model (GAM), we identified three key traits influencing habitat occupancy: hand-wing index, body mass, and range size. Specifically, species with medium hand-wing indices, moderate body mass, and larger range sizes were more likely to occupy heavily fragmented habitats. These findings provide empirical evidence on how habitat fragmentation affects bird species in steppe ecosystems. The study highlights the importance of functional traits in understanding avian responses to habitat fragmentation and offers a foundation for developing effective conservation strategies to preserve biodiversity in fragmented landscapes.