Avian Research最新文献

{"title":"Density dependence and weather drive dabbling duck spatiotemporal distributions and intercontinental migration","authors":"Benjamin Golas ,&nbsp;Diann J. Prosser ,&nbsp;Andrew M. Ramey ,&nbsp;Paul Link ,&nbsp;Wayne E. Thogmartin","doi":"10.1016/j.avrs.2025.100281","DOIUrl":"10.1016/j.avrs.2025.100281","url":null,"abstract":"<div><div>Understanding migratory waterfowl spatiotemporal distributions is important because, in addition to their economic and cultural value, wild waterfowl can be infectious reservoirs of highly pathogenic avian influenza virus (HPAIV). Waterfowl migration has been implicated in regional and intercontinental HPAIV dispersal, and predictive capabilities of where and when HPAIV may be introduced to susceptible spillover hosts would facilitate biosecurity and mitigation efforts. To develop forecasts for HPAIV dispersal, an improved understanding of how individual birds interact with their environment and move on a landscape scale is required. Using an agent-based modeling approach, we integrated individual-scale energetics, species-specific morphology and behavior, and landscape-scale weather and habitat data in a mechanistic stochastic framework to simulate Mallard (<em>Anas platyrhynchos</em>) and Northern Pintail (<em>Anas acuta</em>) annual migration across the Northern Hemisphere. Our model recreated biologically realistic migratory patterns using a first principles approach to waterfowl ecology, behavior, and physiology. Conducting a limited structural sensitivity analysis comparing reduced models to eBird Status and Trends in reference to the full model, we identified density dependence as the main factor influencing spring migration and breeding distributions, and wind as the main factor influencing fall migration and overwintering distributions. We show evidence of weather patterns in Northeast Asia causing significant intercontinental pintail migration to North America. By linking individual energetics to landscape-scale processes, we identify key drivers of waterfowl migration while developing a predictive model responsive to daily weather patterns. This model paves the way for future waterfowl migration research predicting HPAIV transmission, climate change impacts, and oil spill effects.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100281"},"PeriodicalIF":1.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144779343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The product of head height and head width is a strong predictor of brain mass in birds","authors":"Yuran Liu ,&nbsp;Baisalbayeva Rakhima ,&nbsp;Yidong Wei,&nbsp;Jinmei Liu,&nbsp;Wei Liang","doi":"10.1016/j.avrs.2025.100291","DOIUrl":"10.1016/j.avrs.2025.100291","url":null,"abstract":"<div><div>Animal behavioral studies are often combined with research concerning cognitive abilities. Larger brains usually mean more complex neural networks and advanced cognitive functions. By measuring the brain size of different individual animals, we can explore differences in behavioral complexity between populations or species. However, obtaining accurate measurements of brain size is challenging both in field and laboratory environments, especially for rare and endangered species. Therefore, there is an urgent need to develop reliable methods for performing cranial brain mass. This study tests which external structures of the avian head can most accurately predict brain size. We selected five bird species from four orders, categorized external head measures into three types of parameters (direct, calculated and composite measurements), and analyzed these in relation to brain mass. The results showed that while head size can partially explain brain mass, the parameters of head height × head width were the most accurate predictors of brain mass in birds (90.4%). In addition, the positive correlation between endocranial volume and brain mass once again confirmed that avian endocranial volume can, to a certain extent, serve as a valid proxy for brain mass. Our study demonstrates that in the future we can more conveniently perform non-invasive measurements to better understand the relationship between bird brain size and behavior, ecology, and evolution.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100291"},"PeriodicalIF":1.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying avian wing shapes: Evaluating indices, their relationships, and ecological correlates","authors":"Jiahui Li,&nbsp;Canwei Xia","doi":"10.1016/j.avrs.2025.100283","DOIUrl":"10.1016/j.avrs.2025.100283","url":null,"abstract":"<div><div>Avian wings are central to their remarkable flight ability and diverse life history strategies, including behaviors such as fighting and mating. These multifaceted functions are intricately tied to wing shape, which varies significantly across species because of the complex interplay of evolutionary and ecological pressures. Many indices have been developed to quantify wing characteristics to facilitate the study and comparison of avian wing morphology across species. This study provides a comprehensive overview of existing quantitative methods for analyzing avian wing shapes. We then constructed a new quantification framework through the beta distribution, which can generate indices reflecting the shape of avian wings (center, dispersion, skewness, and kurtosis). Next, we used the flight feathers of 613 bird species to perform different quantitative analyses and explore the relationships between various wing shape quantification methods and life history traits, which serve as proxies for the selective forces shaping wing morphology. We find that the wing shape indices are more strongly associated with ecological variables than with morphological variables, especially for migration, habitat and territoriality. This research guides the selection of appropriate methods for wing shape analysis, contributing to a deeper understanding of avian morphology and its evolutionary drivers.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100283"},"PeriodicalIF":1.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144860428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Waterbird image recognition using lightweight deep learning in wetland environment","authors":"Qingquan Huang ,&nbsp;Changchun Zhang ,&nbsp;Chunhe Hu ,&nbsp;Jiangjian Xie ,&nbsp;Yuan Wang ,&nbsp;Junguo Zhang","doi":"10.1016/j.avrs.2025.100306","DOIUrl":"10.1016/j.avrs.2025.100306","url":null,"abstract":"<div><div>Wetland waterbirds serve as key ecological indicators for assessing habitat quality and biodiversity. Accurate identification of waterbird species is a cornerstone of long-term ecological monitoring. The resulting data are critical for assessing wetland ecosystem health and biodiversity. However, prevailing recognition approaches often prioritize detection accuracy at the expense of computational efficiency. They are also hindered by complex background heterogeneity and interspecies visual similarity. These limitations hinder the scalability and practical deployment of such methods for on-site ecological monitoring within wetland ecosystems. To address these challenges, this study proposes an optimized end-to-end framework, ShuffleNetV2-iRMB-ShapeIoU-YOLO (SIS-YOLO), designed for robust recognition of wetland waterbirds in complex environments. Specifically, the proposed framework integrates ShuffleNetV2 with inverted Residual Mobile Blocks (iRMB) to improve computational efficiency while maintaining robust feature representation. This design further enables deployment on resource-constrained mobile and embedded platforms. Additionally, ShapeIoU, a refined bounding box similarity metric, is introduced to jointly optimize overlap and shape consistency, effectively mitigating misclassification among visually similar species. Experimental results on the IC-Beijing dataset show that SIS-YOLO achieves 91.1% precision and 79.1% [email protected]:0.95 with only 2.9 million parameters. Compared with the lightweight baseline YOLOv8n, it improves precision by 2% and [email protected]:0.95 by 1.2%, while requiring fewer parameters and offering higher computational efficiency.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100306"},"PeriodicalIF":1.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145319607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A systematic review of avian response to urbanization in China: Research trends, current insights, and future directions","authors":"Xingmin Chen,&nbsp;Yanping Wang","doi":"10.1016/j.avrs.2025.100292","DOIUrl":"10.1016/j.avrs.2025.100292","url":null,"abstract":"<div><div>Urbanization is one of the most extreme forms of land-use alteration that is advancing across the world with unprecedented speed. As the largest developing country, China has developed a unique path through its high speed and large scale of urbanization, offering valuable research opportunities for avian ecology. However, a comprehensive review on how birds respond to urbanization in China is still lacking. Here, we systematically reviewed 274 studies published from 1962 to 2024 to determine the research trends, current insights, and future directions of avian response to urbanization in China. We synthesized research trends across four core avian response dimensions to urbanization—diversity, behavior, physiology, and life-history—and their applications in conservation strategy design. The number of publications in avian response to urbanization in China increased annually, and it is influenced by China's developing policies of urbanization. The results also showed an unbalanced geographical pattern of the publications, as the research preferences are relatively prevalent in the developed areas of eastern China. In contrast, there are insufficient studies in the emerging urbanizing areas in the western and northeastern China. Regarding the research contents, most existing studies are focusing on the patterns of bird diversity, while there are few studies on the underlying mechanisms, such as physiological adjustments and life-history strategies. In addition, passerines are the most frequent ones among the studied species. Integrating multidimensional urbanization indices and citizen science data are gradually becoming a new trend in recent years. Our study emphasizes that future studies should pay more attention to the response mechanism of birds in urbanizing processes, multidimensional and interdisciplinary studies, and the transformation of the research results into conservation practices.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100292"},"PeriodicalIF":1.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Canalization of globins in the adaptive evolution of birds","authors":"Xiaojia Zhu ,&nbsp;Le Yang ,&nbsp;Quanjian Tao ,&nbsp;Xiran Wang ,&nbsp;Ghulam Nabi ,&nbsp;Fumin Lei ,&nbsp;Xiaoping Yu ,&nbsp;Dongming Li","doi":"10.1016/j.avrs.2025.100293","DOIUrl":"10.1016/j.avrs.2025.100293","url":null,"abstract":"<div><div>The globin superfamily, central to oxygen (O₂) cascade dynamics, exemplifies how canalization—evolutionary stabilization of phenotypic traits—enables vertebrates to thrive in extreme environments. In birds, hemoglobins (Hbs) serve as a paradigm of this process, with structural and functional canalization underpinning their exceptional aerobic capacity and elevational diversification. Despite significant advances of globins in our understanding of avian aerobic adaptation, a comprehensive synthesis of functional diversity, molecular evolution, and structural innovation is essential to fully elucidate their canalized roles in O₂ homeostasis. Integrating perspectives on globin functional diversity and structural evolution, this review examines how chance (mutation/fixation biases) and contingency (historical genetic/epistatic constraints) shape Hb divergence and parallelism, thereby bridging molecular mechanisms with physiological adaptation in birds. We highlight how avian Hbs, canalized through compensatory substitutions and allosteric regulation, achieves a balance between evolutionary robustness and adaptive plasticity. However, critical gaps remain persist: the roles of understudied globins (e.g., neuroglobin, globin E) and the mechanisms of genetic assimilation in migratory taxa. We propose an integrative framework that incorporates ecological divergence (elevation, flight endurance), phylogenetic timescales, and systems biology to unravel how canalization directs adaptive compromise. By focusing on birds within the amniotes, this synthesis advances a cohesive model for vertebrate evolution, wherein canalized globins reconcile metabolic precision with ecological innovation. Ultimately, this review refines hypotheses of O₂ cascade evolution and calls for cross-disciplinary studies to decode the genetic and physiological architecture underlying adaptive canalization in extreme environments.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100293"},"PeriodicalIF":1.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid male plumage evolution drives sexual dichromatism in Ficedula flycatchers","authors":"Lijun Gao,&nbsp;Yueyao Wang,&nbsp;Zheng Li,&nbsp;Lu Dong","doi":"10.1016/j.avrs.2025.100288","DOIUrl":"10.1016/j.avrs.2025.100288","url":null,"abstract":"<div><div>Sexual dichromatism represents a major form of phenotypic differentiation between the sexes in birds, and its evolution is likely shaped by the interplay between sexual and natural selection. The genus <em>Ficedula</em>, widely distributed across Eurasia, exhibits pronounced interspecific variation in both sexual dichromatism and migratory behavior, making it an ideal study system for investigating the evolutionary patterns and drivers of avian sexual dichromatism. In this study, we conducted a phylogenetic comparative analysis of plumage complexity and sexual dichromatism across 32 <em>Ficedula</em> species. We further explored how life-history traits influence the evolution of sexual dichromatism. Our results reveal a strong positive correlation between male plumage complexity and the degree of sexual dichromatism, with males evolving plumage complexity at significantly faster rates than females. Migratory species exhibit significantly higher levels of dichromatism. Furthermore, compared to monochromatic species, sexually dichromatic species are characterized by higher latitudinal occurrence, broader geographic distributions, and greater flight capacity. These findings demonstrated how sexual and natural selection jointly drive evolution of sexual dichromatism in <em>Ficedula</em> within phylogenetic constraints, advancing our understanding of the evolutionary drivers of avian sexual dichromatism.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100288"},"PeriodicalIF":1.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of individual and group factors on the social relationships of Budgerigars","authors":"Xueqi Zhao ,&nbsp;Jiangping Yu ,&nbsp;Jie Su ,&nbsp;Manxi Lu ,&nbsp;Chunguang Dong ,&nbsp;Xiyu Wang ,&nbsp;Haitao Wang","doi":"10.1016/j.avrs.2025.100286","DOIUrl":"10.1016/j.avrs.2025.100286","url":null,"abstract":"<div><div>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 (<em>Melopsittacus undulatus</em>) 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.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100286"},"PeriodicalIF":1.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reproductive resilience and trade-offs: Egg component allocation under nutritional constraints in Japanese Quail","authors":"Gebrehaweria K. Reda ,&nbsp;Sawadi F. Ndunguru ,&nbsp;Renáta Knop ,&nbsp;James K. Lugata ,&nbsp;Brigitta Csernus ,&nbsp;Gabriella Gulyás ,&nbsp;Csaba Szabó ,&nbsp;Ádám Z. Lendvai ,&nbsp;Levente Czeglédi","doi":"10.1016/j.avrs.2025.100278","DOIUrl":"10.1016/j.avrs.2025.100278","url":null,"abstract":"<div><div>Under natural conditions, organisms regularly experience seasonal or unpredictable fluctuations in their diet that may shape the quantity and quality of their reproduction. While these dietary shifts are known to influence overall reproductive output, their specific effects on the proportional composition of egg components remain unexplored. To partially simulate the natural conditions, we conducted two trials using adult Japanese Quails (<em>Coturnix japonica</em>) to examine how dietary restriction and unpredictable feeding influence the proportional composition of egg components. In the first trial, quails were assigned to one of four treatments: full-fed (control) or restricted feeding at 20% (DR20), 30% (DR30), and 40% (DR40) below daily intake. In the second trial, quails were assigned to one of three treatments: full feeding (control), constant 40% restriction (DR40), or unpredictable feeding schedule (UNPR). Each trial lasted for 14 days, and birds were housed individually. Severe dietary restrictions (DR30, DR40) reduced albumen and shell mass, shell thickness, and egg volume. However, yolk mass, yolk color, egg shape index, and shell density remained unaffected across all dietary levels. Severe restrictions also increased the yolk ratio while reducing the albumen ratio, suggesting that birds may evolutionarily prioritize yolk deposition to sustain reproductive functions. However, reduced albumen content due to maternal nutritional stress may also limit essential nutrients, and disrupt the embryo's osmoregulation, which ultimately affects offspring quality. Reduced shell contents at the severe restriction levels can affect the egg's ability to provide physical protection, regulate gas exchange and control water loss, thereby influencing embryonic development. In contrast, moderate restriction (DR20) and unpredictable feeding (UNPR) had no effect on any of the egg traits. These findings suggest that quails strategically allocate resources among egg components under dietary constraints, indicating potential trade-offs in reproductive investment. The resilience observed under moderate restriction and unpredictability underscores the species' adaptive capacity in fluctuating environments.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 3","pages":"Article 100278"},"PeriodicalIF":1.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing urban edge effects: Nest predation rates are higher in areas further from the boundary of a suburban park","authors":"Ailun Wang ,&nbsp;Tara J. Pirie ,&nbsp;Mark D.E. Fellowes","doi":"10.1016/j.avrs.2025.100258","DOIUrl":"10.1016/j.avrs.2025.100258","url":null,"abstract":"<div><div>Urban green spaces and parks offer opportunities for retaining and increasing bird richness, diversity, and species abundance. However, urbanisation influences predator–prey interactions, leading to high predation rates in urban areas, in the UK notably through the presence of large populations of domestic cats and increased populations of synanthropic species, such as rats and squirrels. These high predation rates are assumed to be a significant cause of reproductive failure in birds. Some ecologists advocate for the use of buffer zones with reduced human influence to reduce potential hunting pressure in eco-sensitive areas. However, the buffer effect on predation rates of nesting birds in suburban areas is rarely investigated. In this study, we investigated how edge effects (how close nest sites are to housing) and nest height (i.e., ground vs. above-ground) affected nest predation rates in a suburban park using camera traps to monitor artificial nests containing quail eggs. Our hypothesis was that nests in the buffer area (&lt;300 m inward from university boundary) and at low height would suffer higher predation rates than nests in the core area (&gt;300 m from the university boundary) and at height, as the buffer zone effect, and ease of access to ground predators would result in higher predation rates. We found no significant effect of nest height in nest predation rates. However, contrary to our expectations, nests in the core zone suffered higher predation rates than those in the buffer zone, and corvids were responsible for almost half of the egg loss events. We speculate that this may be a consequence of higher levels of anthropogenic disturbance (e.g., pedestrians, dog walking, vehicles) adjacent to our buffer zone acting as a deterrent to avian nest predators. This work suggests that protecting urban sites from disturbance may not always act to support bird abundance.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 3","pages":"Article 100258"},"PeriodicalIF":1.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}