Human-modified landscapes serve as ecological filters, determining species distributions and persistence. Energy-efficient technologies, while crucial for climate change mitigation, represent novel filters whose impacts on synanthropic biodiversity are poorly understood. We investigated how attached sunspaces, a widely adopted energy-saving technology in rural China, filter the distribution of two ecologically important aerial insectivores, the Barn Swallow (Hirundo rustica) and Red-rumped Swallow (Cecropis daurica). We surveyed 106 villages during the 2024 and 2025 breeding seasons and recorded a total of 2323 nests (612 Barn Swallow, 1711 Red-rumped Swallow). Using Generalized Linear Models, we assessed their responses to building characteristics, landscape composition and the prevalence of sunspaces. Barn Swallow nests preferred perches at the base and single attachment faces, while Red-rumped Swallow nests favored multiple attachment faces and avoided long shelters. The proportion of buildings with sunspaces acted as a strong positive filter for Barn Swallow nest abundance (+24%) but as a significant negative filter for Red-rumped Swallow (−51%). Other landscape variables (e.g., human population density, NDVI, Human Footprint Index) were not significant. This study demonstrates that specific architectural innovations can act as powerful ecological filters, leading to divergent distributional outcomes for sympatric species reliant on anthropogenic structures. Our findings reveal a critical trade-off in sustainable development: energy efficiency gains may inadvertently reduce habitat suitability for certain species. To reconcile climate and biodiversity goals in rural landscapes, we advocate integrating species-specific habitat requirements into building design. We propose actionable modifications to sunspaces to support swallows without compromising energy savings. These principles provide a template for mitigating the distributional impacts of green infrastructure globally.

Social animals often form dynamic relationships with group members, which have been associated with increased social learning, survival and reproductive success. Social relationships can be shaped by both group and individual factors; however, few studies have addressed their combined impact. In this study, we aimed to examine whether group factors and individual factors jointly affect social relations. We selected Budgerigars (Melopsittacus undulatus) as the focal species to investigate the influence of sex, personality, and body length as well as sex ratio and group size on social relationships. The results showed that the birds in 3-individual groups had higher aggression network weighted degree values than those in 5-individual groups. Individuals within opposite-sex groups showed higher levels of aggressive and affiliative interactions than those in same-sex groups. Additionally, females attained higher social ranks despite exhibiting significantly lower aggression behaviors than males. Individuals with longer body lengths exhibited higher aggression network weighted degree values. Our results suggest that group factors primarily influence the social networks, while individual factors play important roles in shaping the social relationships.

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.

The process of agricultural intensification has led to significant reductions in biodiversity globally. Previous studies examined the role of semi-natural habitats within agroecosystems in supporting bird communities, but few have considered the effects of landscape agricultural intensity on avian conservation potential of semi-natural habitats. Here, we disentangle the relative effects of semi-natural habitats within different landscape agricultural intensities on bird community composition in central and eastern Jilin Province, China. We established 322 sampling sites distributed across low, middle, and high landscape agricultural intensities, with 103, 118, and 101 sites respectively. Each sampling site was visited two times in May and June 2023 to test the dissimilarities in bird composition between different landscape agricultural intensities. We found that middle-intensity agriculture supported the highest bird diversity in most cases, but low-intensity plays an important role in maintaining insectivorous birds. We used generalized linear models and model selection to assess the relative impacts of semi-natural habitats on bird community along agricultural intensity respectively. Our results showed that the effects of agriculture on bird communities were predominantly influenced by the amount of semi-natural habitats, with effects that differ in accordance with the level of landscape agricultural intensity. Priority should be given to preserve or/and plant these semi-natural habitats in middle-intensity agriculture due to the stronger effect sizes on bird diversity. Specifically, we suggested preserving and promoting woodlands and shrubs in high-intensity agriculture, and simultaneously increasing crop diversity to protect bird diversity in agriculture landscapes in the context of increasing crop intensification globally.

The transformation of natural habitats into human-modified landscapes has far-reaching consequences for species distribution and abundance. As species adapt to these changing environments, shifts in distribution patterns, niche dynamics, and interspecies interactions may occur, impacting biodiversity at multiple levels and potentially leading to ecosystem imbalances. This study aims to assess the impact of variations in vegetation composition and human disturbance on the distribution of sympatric breeding birds and to determine the extent of niche overlap or differentiation among these species. We conducted field surveys and collected data on bird distribution, vegetation composition, and level of human disturbance in eastern Inner Mongolian grasslands. We focused on the six most frequently co-occurring breeding birds, representing a mix of sparrows, larks, and corvids. Generalized Additive Models revealed varying responses of species occurrence along habitat gradients. Species like the Eurasian Skylark (Alauda arvensis), Mongolian Lark (Melanocorypha mongolica), and Asian Short-toed Lark (Calandrella cheleensis), increased in larger and more connected habitats, while others, like the Tree Sparrow (Passer montanus), Eurasian Magpie (Pica pica), and Barn Swallow (Hirundo rustica), adapted to more fragmented habitats. Niche analysis indicated habitat generalists tended to occupy larger niches than grassland specialists. Substantial niche overlap was also found among the six co-occurring bird species. Conservation efforts should consider the specific needs of specialist species and strive to maintain or restore critical grassland habitats. Additionally, promoting sustainable agricultural practices that balance the needs of birds and human activities can contribute to the coexistence of generalist and specialist bird species in modified landscapes.

Individuals may gather information about environmental conditions when deciding where to breed in order to maximize their lifetime fitness. They can obtain social information by observing conspecifics and heterospecifics with similar ecological needs. Many studies have shown that birds can rely on social information to select their nest sites. The location of active nests and the reproductive success of conspecifics and heterospecifics can provide accurate predictions about the quality of the breeding habitat. Some short-lived species can facultatively reproduce two and/or more times within a breeding season. However, few studies have focused on how multiple-brooding individuals select nest sites for their second breeding attempts. In this study, we use long-term data to test whether the Japanese Tit (Parus minor) can use social information from conspecifics and/or heterospecifics (the Eurasian Nuthatch Sitta europaea, the Daurian Redstart Phoenicurus auroreus and the Yellow-rumped Flycatcher Ficedula zanthopygia) to select a nest site for the second breeding attempt. Our results showed that the nest boxes occupied by tits on their second breeding attempt tended to be surrounded by more breeding conspecific nests, successful first nests of conspecifics, and fewer failed first nests of conspecifics than the nest boxes that remained unoccupied (the control group). However, the numbers of breeding heterospecific nests, successful heterospecific nests, and failed heterospecific nests did not differ between the nest boxes occupied by tits on their second breeding attempt and the unoccupied nest boxes. Furthermore, the tits with local successful breeding experience tended to choose areas with more successful first nests of conspecifics than those without successful breeding experience. Thus, we suggest that conspecifics' but not heterospecifics’ social information within the same breeding season is the major factor influencing the nest site selection of Japanese Tits during second breeding attempts.

Biodiversity is declining at an unprecedented rate. Many grassland species have been lost and are now of conservation concern. Identifying efficient biodiversity indicators is a key pillar of the global conservation strategy. Mongolian Lark (Melanocorypha mongolica) is a charismatic bird species abound in Mongolian steppes, and recent studies demonstrated that this species share similar habitat requirements and likely co-occur with other grassland birds. We tested the hypothesis that Mongolian Lark would make a suitable indicator for different aspects of avian biodiversity. We made a large-scale bird survey in Inner Mongolia, and classified point counts into three groups based on different taxonomic, functional, and phylogenetic biodiversity measures. We identified species indicators of each group using the indicator value (IndVal) analysis, and examined the bird compositional difference among groups. Linear models were used for studying the patterns of occurrence of Mongolian Lark in relation to various biodiversity measures. Mongolian Lark showed the highest indicator value in comparison with other potential species indicators. Bird species richness is significantly higher at sites with Mongolian Lark, and its occurrence was negatively correlated with species abundance, functional richness, Rao's quadratic entropy and phylogenetic diversity. Mongolian Lark is therefore a suitable indicator species for avian biodiversity in Mongolian steppes. It is highly distinctive in flight and usually seen singly. The widespread distribution and charismatic appearance make it easy to monitor and adequate for citizen science, and may provide useful information on the paradigm of surrogacy in conservation ecology.

The reproductive behaviors of birds are mainly controlled by the hypothalamus-pituitary-gonad axis. Many studies have shown that reproductive hormones are tightly linked to the breeding sub-stages. However, only a few studies have examined the temporal trend of hormone levels among different reproductive stages in multiple brooded species. We investigated the changes in plasma luteinizing hormone (LH) and prolactin (PRL) concentrations during different reproductive stages of the facultative double-brooded Great Tit (Parus major). We found that the concentrations of LH and PRL in females were significantly higher than those in males. Females had significantly higher LH and lower PRL concentrations in the pre-breeding period than in the first/second brooding periods, and there were no significant changes between the first and second brooding periods. The concentrations of LH and PRL in males had no significant difference between the pre-breeding period and the first brooding periods, while LH and PRL concentrations in the second brooding period were significantly higher than those in the first brooding period. We conclude that there are sex-based differences between LH and PRL at different stages of reproduction. The changes in LH and PRL in both males and females should be related to their physiological functions. Especially for males, individuals with higher levels of LH and PRL are more likely to maintain second clutches.