摘要: Photoperiod serves as an essential environmental cue that facilitates seasonal acclimatization and thermoregulation in birds.However,its effects on basal and substrate metabolism in Zebra Finches(Taeniopygia guttata)remain unclear.To explore the influence of photoperiod on basal metabolism and substrate metabolism in Zebra Finches,basal metabolic rate(BMR),body mass,cellular metabolic activities,and substrate metabolism were investigated under different photoperiods.After one week of exposure to a short photoperiod,Zebra Finches exhibited a temporary decrease in BMR,gross energy intake,digestible energy intake,and digestibility,although body mass remained unchanged throughout the experiment.After four weeks of acclimation,no significant differences were observed among different groups in state 4 respiration,cytochrome c oxidase activity,citrate synthase activity,avian uncoupling protein expression,or circulating triiodothyronine and thyroxine hormone levels.In terms of substrate metabolism,short photoperiod-exposed finches showed increased pectoral muscle glycogen content and elevated serum triglyceride and free fatty acid levels,accompanied by a decrease in body fat.No differences were detected in serum glucose levels or in the activity and mRNA levels of carnitine palmityltransferase-1 and β-hydroxyacyl Co-A dehydrogenase.These findings suggest that changes in photoperiod may serve as signals for substrate metabolism remodeling,while having only transient effects on basal metabolism in Zebra Finches.

摘要: Gynandromorphs,rare in vertebrates,exhibit distinct sex-determining gene expression on each side of the body despite sharing a uniform hormonal environment.This provides a unique opportunity to investigate the respective roles of genes and hormones in sex determination.We accidently obtained a gynandromorphic Zebra Finch with a male-female chimeric appearance but only with an ovary-like gonad.Its plasma estradiol was significantly higher than that of age-matched females,and its sexual partner preference was also feminine.Although it did not sing like males,its calls showed masculinization.In the brain on one side of the body with male plumage,the area of song motor nucleus,the robust nucleus of the arcopallium(RA),and the excitatory synaptic transmission of RA projection neurons showed masculinization.Transcriptome analysis revealed that genes related to cholinergic neuron function were significantly upregulated in the masculinized side of brain.Moreover,there were extensive and consistent expression differences of neuroactive substance receptor genes in both sides of body,indicating that cell-autonomous determination plays a key role in sex dimorphism of neuromodulation.

摘要: Avian cognitive abilities rival those of primates.These capacities have been linked to high pallial neuronal density and prefrontal cortex-like dorsal ventricular ridge(DVR) circuitry.Although the DVR is now recognized as a pallial structure homologous to the mammalian cortex,its morphological basis remains unclear.Here,we combine Nissl staining,Golgi-Cox labeling,and 3D reconstruction to map neuronal morphology across five telencephalic regions in the Rock Pigeon(Columba livia).From 64 fully reconstructed neurons,we quantified dendritic field area,total dendritic length,branching architecture,and radial arbor organization.DVR neurons showed the largest dendritic fields and the highest branching complexity.Single-nucleus transcriptomic data further revealed that the Nidopallium Caudolaterale(NCL),the core DVR subregion,expresses a neuronmorphogenesis gene module whose activity correlates with dendritic field size.Together,these results identify a molecular and morphological signature of DVR neurons and highlight the computational significance of Nidopallium Caudolaterale.This work provides an integrated comparison of telencephalic neuronal morphology and gene expression in birds.

摘要: The critically endangered Chinese Crested Tern(CThalasseus bernsteini,CCT) and its common flocking companion,the Greater Crested Tern(Thalasseus bergii,GCT),have been the focus of targeted recovery efforts in the Jiushan Archipelago of Zhejiang Province,China since 2013.To evaluate the long-term effectiveness of these measures and address key knowledge gaps in population dynamics and migration ecology,we analyzed ten years(2015-2024) of banding and citizen science data,comprising 116 CCT and 3501 GCT resighting records.We estimated survival rates using both directly derived survival rate(based on resighting rate after two years) and Cormack-Jolly-Seber modeling,and examined migration connectivity and climate risks.Results showed robust juvenile survival:modeled survival for the tern chick population was lower in the first two years(63.9±12.0%)but exceeded 78% thereafter.This was also supported by resighting rate after two years:CCT 77.27%,GCT70.42%.A key divergence in post-breeding migration was identified:CCT moves northward to stopover sites such as Nantong,Rizhao,and Jiaozhou Bay,whereas GCT migrates southward.Climate data confirmed that northern stopover sites do not pose higher storm risks,indicating that CCT's northward migration is not a population liability.Furthermore,connectivity among breeding islands in Zhejiang and the Matsu Archipelago reveals a nascent coastal breeding network along China's coast.These findings underscore the importance of protecting both the northern migration route and the breeding island network to ensure full life-cycle conservation of CCT.

摘要: The collection and annotation of lar ge-scale bird datasets are resource-intensive and time-consuming processes that significantly limit the scalability and accuracy of biodiversity monitoring systems.While self-supervised learning（SSL） has emerged as a promising approach for leveraging unannotated data,current SSL methods face two critical challenges in bird species recognition:（1） long-tailed data distributions that result in poor performance on underrepresented species;and（2） domain shift issues caused by data augmentation strategies designed to mitigate class imbalance.Here we present SDNet,a novel SSL-based bird recognition framework that integrates diffusion models with large language models（LLMs） to overcome these limitations.SDNet employs LLMs to generate semantically rich textual descriptions for tail-class species by prompting the models with species taxonomy,morphological attributes,and habitat information,producing detailed natural language priors that capture fine-grained visual characteristics（e.g.,plumage patterns,body proportions,and distinctive markings）.These textual descriptions are subsequently used by a conditional diffusion model to synthesize new bird image samples through cross-attention mechanisms that fuse textual embeddings with intermediate visual feature representations during the denoising process,ensuring generated images preserve species-specific morphological details while maintaining photorealistic quality.Additionally,we incorporate a Swin Transformer as the feature extraction backbone whose hierarchical window-based attention mechanism and shifted windowing scheme enable multi-scale local feature extraction that proves particularly effective at capturing finegrained discriminative patterns（such as beak shape and feather texture） while mitigating domain shift between synthetic and original images through consistent feature representations across both data sources.SDNet is validated on both a self-constructed dataset（Bird_BXS） an d a publicly available benchmark（Birds₂5）,demonstrating substantial improvements over conventional SSL approaches.Our results indicate that the synergistic integration of LLMs,diffusion models,and the Swin Transformer architecture contributes significantly to recognition accuracy,particularly for rare and morphologically similar species.These findings highlight the potential of SDNet for addressing fundamental limitations of existing SSL methods in avian recognition tasks and establishing a new paradigm for efficient self-supervised learning in large-scale ornithological vision applications.

摘要: Monitoring waterbirds is vital for evaluating the ecological health of wetlands,and object detection offers an automated solution for identifying birds in monitoring imagery.However,conventional detection methods often overlook the multi-scale nature of bird targets,limiting their ability to capture rich contextual information across different scales.To address this,we propose a cross-dimensional attention network(CDA-Net) for bird detection that integrates spatial and channel information to improve species recognition.The proposed CDA-Net partitions feature maps into multiple channel wise sub-features.Spatial and channel attention are applied to each subfeature,and the resulting features are fused using the Hadamard product.The fused features are then forwarded to the detection head to generate the final detection results.This approach effectively captures and integrates information across spatial and channel dimensions.Experiments on our self-constructed Nanhai Wetland Waterbird Dataset and the public CUB-200-2011 dataset yield precision scores of 91.32% and 81.99%,respectively,outperforming existing methods.Our approach effectively handles scale variation in bird detection and provides a valuable tool for advancing automated wetland waterbird monitoring.

摘要: Penduline tits(genus Remiz) are small passerines distributed across Europe,Central and East Asia,and North Africa,renowned for their elaborate nests and unusually diverse mating systems.However,the taxonomy and evolutionary relationships within this genus have remained contentious due to overlapping breeding distributions and extensive hybridization.Using broad-range geographic sampling and whole-genome sequencing,here we report the phylogenetic relationships within this genus.Our results from maximum likelihood trees,species trees,population structure,and PCA analyses consistently identify four distinct,well-supported monophyletic clades.Based on these robust results,we support dividing Remiz into four species:the Eurasian Penduline Tit(R.pendulinus),Black-headed Penduline Tit(R.macronyx),White-crowned Penduline Tit(R.coronatus),and Chinese Penduline Tit(R.consobrinus).Among these species,R.consobrinus diverged earlier from other species,followed by R.coronatus,and then,R.pendulinus and R.macronyx.R.pendulinus and R.macronyx showed shallow genetic differentiation with recent divergence(～87,000 years ago) and ongoing gene flow.Our findings demonstrate the effectiveness of phylogenomic approaches in resolving taxonomic ambiguities and provide a robust evolutionary framework for tracing the diversification of life history traits,particularly nest structures and mating systems,across the genus.

摘要: In recent years bird hunting has become a topical issue in public debate in Poland. Some organizations and communities actively engaged in nature conservation efforts propose a complete ban on hunting, arguing it needs to be introduced for ethical reasons and to ensure a more effective species protection. This discussion frequently involves cases when hunters break the law, illustrated by photographs published on social media, documenting culling of legally protected species. In response hunters mention the need to verify the sources and the context for published materials.

摘要: Urbanization has profoundly reshaped biodiversity,yet its impacts on community seasonal changes remain poorly understood.Here,we used citizen science data from 839 bird species in 37 cities and their corresponding rural areas in China to assess how urbanization alters seasonal changes in bird communities.We calculated Sørensen beta dissimilarity indices(β_sor) between seasons to compare the seasonality of communities in urban and rural areas and decomposed these indices into turnover(β_sim) and nestedness(β_nes) components.We evaluated whether there are differences in the latitudinal clines in community seasonality between urban and rural areas,and explored whether environmental and socio-economic factors affect the urbanization-driven changes in community seasonality.Our results show that the overall seasonal β_sor in urban communities was 16.2% higher than in rural areas,due to a 49.5% increase in β_nes（urban:0.22±0.12 vs.rural:0.15±0.08）,but there was no significant difference in β_sim.In rural areas,β_sor increased with latitude,but β_sor showed no latitudinal trend in urban communities.Human population emerges as a key predictor of urbanization-driven changes in the species turnover and nestedness components,with larger cities showing lower species turnover but higher nestedness components.We conclude that urbanization alters the seasonality of bird communities through nestedness components,decouples the relationship between community seasonality and latitude,and concentrates its impacts in densely populated cities.Future research must employ long-term monitoring to track how urbanization changes bird communities in space and time.

摘要: Habitat loss driven by land-use change is a major factor shaping the dynamics of urban bird community structures.However,the potential mechanisms by which the spatial configuration and composition of blue-green infrastructure,recognized as biodiversity hotspots in urban landscapes,influence urban bird beta diversity remain insufficiently understood.This study was conducted in the built-up area of Yinchuan,an internationally recognized wetland city in Northwest China.From December 2023 to June 2024,we systematically surveyed bird communities during both the breeding and wintering periods across 29 blue-green space mosaics.We quantified taxonomic,functional,and phylogenetic beta diversity,along with their turnover component and nestedness-resultant component,based on both pairwise beta diversity and multiple-site beta diversity.We further assessed the relative importance of landscape variables and spatial geographic distance in shaping beta diversity patterns and used hierarchical modeling of species communities(HMSC) to explore the responses of bird occurrence and functional traits to landscape variables.Our results revealed that species turnover was the dominant driver of taxonomic,functional,and phylogenetic beta diversity.Seasonal differences were observed in the effects of spatial geographic distance and landscape structure on beta diversity and its components,with landscape variables showing higher explanatory power than geographic isolation.In the breeding period,landscape diversity and waterbody area had positive effects on bird occurrence,whereas in the wintering period,most landscape features—except for landscape diversity—exerted neutral or negative influences.Regarding functional traits,we found that reproductive traits,flight ability,and foraging characteristics responded significantly to landscape structure,and that some small-bodied species active in aerial and canopy layers were more adaptable to habitat fragmentation.This study provides novel insights into the assembly processes and driving mechanisms of urban bird communities and offers scientific support for the notion that designing and maintaining blue-green infrastructure can contribute to urban biodiversity conservation.