Anthropogenic climate change is altering species distributions globally. While species distributions are expected to shift to higher latitudes and elevations under global warming, empirical evidence on distribution shifts is mixed, and factors mediating the direction and magnitude of range shifts remain unclear. Using a dataset of 132 new provincial records for 96 resident bird species from 2000 to 2023, we measured geographic distance, latitudinal shift, and temperature shift from each new record to the historical range for each species to test for poleward shifts. We assessed taxonomic variation in the magnitude of range shifts and used phylogenetic generalized linear mixed models to quantify relationships between species traits and the extent of range shifts. Our results revealed that new records occurred at a mean geographic distance of 420 km from historical ranges, with mean latitudinal shifts of +1.68° (poleward) and temperature shifts of −1.33 °C (toward colder climates). The magnitude of geographic range shifts was strongly constrained by phylogenetic relatedness. Habitat breadth, habitat openness, and centroid latitude of historical ranges emerged as significant predictors of range shifts. Our results suggest that resident bird species’ geographic ranges in China are shifting poleward, but the magnitude of these shifts is non-random across lineages. Species with broader habitat preferences and those from warmer climates are more likely to shift farther from their historical ranges and toward higher latitudes. This study emphasizes taxonomic variation in species range shifts and highlights the need for species- and site-specific conservation strategies under global warming.
{"title":"Chinese provincial-level new records for 96 resident bird species reveal poleward range shifts","authors":"Shengxi Chen, Zhehao Chen, Hongtao Lin, Haoting Duan, Jiehua Yu, Jiekun He","doi":"10.1016/j.avrs.2025.100310","DOIUrl":"10.1016/j.avrs.2025.100310","url":null,"abstract":"<div><div>Anthropogenic climate change is altering species distributions globally. While species distributions are expected to shift to higher latitudes and elevations under global warming, empirical evidence on distribution shifts is mixed, and factors mediating the direction and magnitude of range shifts remain unclear. Using a dataset of 132 new provincial records for 96 resident bird species from 2000 to 2023, we measured geographic distance, latitudinal shift, and temperature shift from each new record to the historical range for each species to test for poleward shifts. We assessed taxonomic variation in the magnitude of range shifts and used phylogenetic generalized linear mixed models to quantify relationships between species traits and the extent of range shifts. Our results revealed that new records occurred at a mean geographic distance of 420 km from historical ranges, with mean latitudinal shifts of +1.68° (poleward) and temperature shifts of −1.33 °C (toward colder climates). The magnitude of geographic range shifts was strongly constrained by phylogenetic relatedness. Habitat breadth, habitat openness, and centroid latitude of historical ranges emerged as significant predictors of range shifts. Our results suggest that resident bird species’ geographic ranges in China are shifting poleward, but the magnitude of these shifts is non-random across lineages. Species with broader habitat preferences and those from warmer climates are more likely to shift farther from their historical ranges and toward higher latitudes. This study emphasizes taxonomic variation in species range shifts and highlights the need for species- and site-specific conservation strategies under global warming.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100310"},"PeriodicalIF":1.7,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362208","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}
Pub Date : 2025-10-10DOI: 10.1016/j.avrs.2025.100308
Deming Shen , Fawen Qian , Shaoxia Xia , Chaoyang Wang , Xu Chu , Zhenyu Wang , Hongxing Jiang , Yankuo Li
Poyang Lake, China's largest freshwater lake, is a critical wintering ground for most of the global Siberian Crane (Grus leucogeranus) population. However, increasingly prolonged dry seasons have degraded the natural wetlands of Poyang Lake, forcing Siberian Cranes to shift to artificial habitats. From 2015 to 2023, field surveys revealed a substantial increase in the number of Siberian Cranes in artificial habitats, with peak counts reaching 3000 individuals, accounting for up to 53% of the species' global population. Satellite telemetry of 13 individuals further confirmed the spatial use of these habitats, highlighting their consistent reliance on artificial sites over multiple years. Seven high-use hotspots were identified outside of Poyang Lake, including two artificial provisioning sites that supported dense foraging flocks for extended periods. Satellite telemetry confirmed this trend, with artificial habitats making up to 64.2% of the occurrence sites in some years. This reliance on artificial habitats was closely linked to the reduced tuber biomass in natural wetlands and low winter water levels in Poyang Lake, which collectively explained 83% of the variance in crane abundance in artificial habitats. Artificial habitat use peaked in December and January, indicating marked seasonal variation. Siberian Cranes also exhibited a pronounced circadian rhythm, foraging in artificial habitats during the day and returning to natural wetlands to roost at night. Despite the shift toward artificial habitats, natural wetlands remain critical for nighttime refuge. The continued dependence on artificial habitats raises concerns about disease transmission owing to dense congregations. Conservation strategies should prioritize both the careful management of artificial provisioning sites and the restoration of natural wetlands to improve food and habitat availability within natural ecosystems, ultimately enabling the return of Siberian Cranes to their traditional natural habitats.
{"title":"Impacts of prolonged dry season and artificial food supply on the wintering spatial distribution of Siberian Cranes: Implications for conservation","authors":"Deming Shen , Fawen Qian , Shaoxia Xia , Chaoyang Wang , Xu Chu , Zhenyu Wang , Hongxing Jiang , Yankuo Li","doi":"10.1016/j.avrs.2025.100308","DOIUrl":"10.1016/j.avrs.2025.100308","url":null,"abstract":"<div><div>Poyang Lake, China's largest freshwater lake, is a critical wintering ground for most of the global Siberian Crane (<em>Grus leucogeranus</em>) population. However, increasingly prolonged dry seasons have degraded the natural wetlands of Poyang Lake, forcing Siberian Cranes to shift to artificial habitats. From 2015 to 2023, field surveys revealed a substantial increase in the number of Siberian Cranes in artificial habitats, with peak counts reaching 3000 individuals, accounting for up to 53% of the species' global population. Satellite telemetry of 13 individuals further confirmed the spatial use of these habitats, highlighting their consistent reliance on artificial sites over multiple years. Seven high-use hotspots were identified outside of Poyang Lake, including two artificial provisioning sites that supported dense foraging flocks for extended periods. Satellite telemetry confirmed this trend, with artificial habitats making up to 64.2% of the occurrence sites in some years. This reliance on artificial habitats was closely linked to the reduced tuber biomass in natural wetlands and low winter water levels in Poyang Lake, which collectively explained 83% of the variance in crane abundance in artificial habitats. Artificial habitat use peaked in December and January, indicating marked seasonal variation. Siberian Cranes also exhibited a pronounced circadian rhythm, foraging in artificial habitats during the day and returning to natural wetlands to roost at night. Despite the shift toward artificial habitats, natural wetlands remain critical for nighttime refuge. The continued dependence on artificial habitats raises concerns about disease transmission owing to dense congregations. Conservation strategies should prioritize both the careful management of artificial provisioning sites and the restoration of natural wetlands to improve food and habitat availability within natural ecosystems, ultimately enabling the return of Siberian Cranes to their traditional natural habitats.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100308"},"PeriodicalIF":1.7,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145319603","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}
Pub Date : 2025-10-04DOI: 10.1016/j.avrs.2025.100307
Shen Han Teo , Yong Chee Keita Sin , Mayjean Marie Ines Nieves, Frank E. Rheindt
Quantitative analysis of colouration is an essential tool for subspecies delimitation but has always posed a challenge in avian taxonomy. In this study on the Chestnut-winged Babbler (Cyanoderma erythropterum) species complex from tropical Southeast Asia, we made use of colour measurements taken with digital cameras and applied two methodologies—(1) the 75% subspecies rule on quantitative colourimetric variables, and (2) the CIEDE2000 colour distance method to generate phylograms, which has probably never been applied in taxonomy before. Given its large number of described subspecies, many of which have been synonymised in modern taxonomies, the species complex serves as an appropriate model to test subspecies validity. Our data indicate that one synonymised subspecies (C. e. apega), from the islands of Bangka and Belitung, requires re-instalment and recognition, whereas one widely recognised subspecies (C. e. fulviventre), from the Banyak Islands, should be synonymised. Our approach also allowed us to redraw geographic subspecies boundaries. Our work indicates that current subspecies taxonomies of many poorly known tropical species may remain error-ridden and highlights the importance and viability of large-scale taxonomic revisions targeting avian subspecies globally while incorporating quantitative colourimetric approaches.
颜色定量分析是亚种划分的重要工具，但一直是鸟类分类学研究的难点。本研究利用数码相机对东南亚热带地区的栗翅Babbler （Cyanoderma erythropterum）种群进行了颜色测量，并采用了两种方法(1)定量比色变量的75%亚种规则和(2)CIEDE2000颜色距离法生成系统图，该方法在分类中可能从未被应用过。鉴于其描述的亚种数量众多，其中许多在现代分类学中已被同义词化，物种复合体可以作为测试亚种有效性的适当模型。我们的数据表明，来自Bangka岛和Belitung岛的一个同义亚种（C. e. apega）需要重新安装和识别，而来自Banyak岛的一个广泛认可的亚种（C. e. fulviventre）应该被同义化。我们的方法还允许我们重新绘制地理上的亚种边界。我们的工作表明，目前许多鲜为人知的热带物种的亚种分类可能仍然存在错误，并强调了在采用定量比色方法的同时，针对全球鸟类亚种进行大规模分类修订的重要性和可行性。
{"title":"Birds of a feather: Comprehensive plumage colour analysis for a revised subspecies classification of the Chestnut-winged Babbler (Cyanoderma erythropterum) species complex","authors":"Shen Han Teo , Yong Chee Keita Sin , Mayjean Marie Ines Nieves, Frank E. Rheindt","doi":"10.1016/j.avrs.2025.100307","DOIUrl":"10.1016/j.avrs.2025.100307","url":null,"abstract":"<div><div>Quantitative analysis of colouration is an essential tool for subspecies delimitation but has always posed a challenge in avian taxonomy. In this study on the Chestnut-winged Babbler (<em>Cyanoderma erythropterum</em>) species complex from tropical Southeast Asia, we made use of colour measurements taken with digital cameras and applied two methodologies—(1) the 75% subspecies rule on quantitative colourimetric variables, and (2) the CIEDE2000 colour distance method to generate phylograms, which has probably never been applied in taxonomy before. Given its large number of described subspecies, many of which have been synonymised in modern taxonomies, the species complex serves as an appropriate model to test subspecies validity. Our data indicate that one synonymised subspecies (<em>C. e. apega</em>), from the islands of Bangka and Belitung, requires re-instalment and recognition, whereas one widely recognised subspecies (<em>C. e. fulviventre</em>), from the Banyak Islands, should be synonymised. Our approach also allowed us to redraw geographic subspecies boundaries. Our work indicates that current subspecies taxonomies of many poorly known tropical species may remain error-ridden and highlights the importance and viability of large-scale taxonomic revisions targeting avian subspecies globally while incorporating quantitative colourimetric approaches.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100307"},"PeriodicalIF":1.7,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145319608","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}
Pub Date : 2025-10-04DOI: 10.1016/j.avrs.2025.100306
Qingquan Huang , Changchun Zhang , Chunhe Hu , Jiangjian Xie , Yuan Wang , Junguo Zhang
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.
{"title":"Waterbird image recognition using lightweight deep learning in wetland environment","authors":"Qingquan Huang , Changchun Zhang , Chunhe Hu , Jiangjian Xie , Yuan Wang , 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":"2025-10-04","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}
Pub Date : 2025-10-01DOI: 10.1016/j.avrs.2025.100305
Daojian Chen , Xiaohui Gao , Min Zhang , Xianli Che , Qiang Zhang , Daniel R. Gustafsson , Zhengzhen Wang , Anders P. Møller , Alexandra Grossi , Fasheng Zou
Estimating bird abundance is key to assess threats, and to prioritize conservation actions. However, few studies focus on this topic, particularly in developing countries, which may hamper conservation efficiency. We used data collected from Guangdong Province, China, between 2000 and 2020 to estimate bird abundance using MaxEnt modelling. In total, 258 bird species were included, with an average density of 1485.2 ± 489.3 ind./km2 (range: 242.9–4502.2 ind./km2). The highest density occurred in the Pearl River Estuary and on the Leizhou Peninsula. For forest birds, 203 species were included with an average density of 1236.2 ± 424.5 ind./km2 (143.7–2373.1 ind./km2), and highest densities were found in the Pearl River Estuary and North River regions. For the 55 species of waterbirds, the average density was 249.0 ± 351.8 ind./km2 (0.3–2336.1 ind./km2). The total number of birds in Guangdong was estimated to be 2.58 × 108 ind. (2.24–3.06 × 108), with a total number of forest birds estimated to be 2.15 × 108 ind. (1.90–2.49 × 108). The most abundant forest species (>107 individuals) were: Huet's Fulvetta (Alcippe hueti) with 2.84 × 107 ind., (range: 2.73–2.95 × 107), Light-vented Bulbul (Pycnonotus sinensis) with 1.13 × 107 ind. (1.07–1.20 × 107), Swinhoe's White-eye (Zosterops simplex) with 1.13 × 107 ind. (1.09–1.17 × 107), and Red-whiskered Bulbul (Pycnonotus jocosus) with 1.01 × 107 ind. (9.66–10.47 × 106). The total number of waterbirds in Guangdong was estimated to be 4.37 × 107 ind. (3.38–5.75 × 107). The most abundant waterbirds (>106 individuals) were Black-headed Gull (Chroicocephalus ridibundus) with 6.35 × 106 ind. (5.48–7.36 × 106), Pied Avocet (Recurvirostra avosetta) with 5.56 × 106 ind. (3.75–8.24 × 106), and Little Egret (Egretta garzetta) with 5.01 × 106 ind. (4.19–6.00 × 106). The densities and abundances of the 41 species listed as threatened in IUCN (higher than NT) or Chinese National Protected lists (higher than II) were evaluated, of which the population sizes of nine species were estimated for the first time in Guangdong. Moreover, all 41 species' average densities significantly declined from 2012 to 2017 in Nanling National Natural Reserve, Guangdong.
{"title":"How many birds are there in Guangdong Province, China?","authors":"Daojian Chen , Xiaohui Gao , Min Zhang , Xianli Che , Qiang Zhang , Daniel R. Gustafsson , Zhengzhen Wang , Anders P. Møller , Alexandra Grossi , Fasheng Zou","doi":"10.1016/j.avrs.2025.100305","DOIUrl":"10.1016/j.avrs.2025.100305","url":null,"abstract":"<div><div>Estimating bird abundance is key to assess threats, and to prioritize conservation actions. However, few studies focus on this topic, particularly in developing countries, which may hamper conservation efficiency. We used data collected from Guangdong Province, China, between 2000 and 2020 to estimate bird abundance using MaxEnt modelling. In total, 258 bird species were included, with an average density of 1485.2 ± 489.3 ind./km<sup>2</sup> (range: 242.9–4502.2 ind./km<sup>2</sup>). The highest density occurred in the Pearl River Estuary and on the Leizhou Peninsula. For forest birds, 203 species were included with an average density of 1236.2 ± 424.5 ind./km<sup>2</sup> (143.7–2373.1 ind./km<sup>2</sup>), and highest densities were found in the Pearl River Estuary and North River regions. For the 55 species of waterbirds, the average density was 249.0 ± 351.8 ind./km<sup>2</sup> (0.3–2336.1 ind./km<sup>2</sup>). The total number of birds in Guangdong was estimated to be 2.58 × 10<sup>8</sup> ind. (2.24–3.06 × 10<sup>8</sup>), with a total number of forest birds estimated to be 2.15 × 10<sup>8</sup> ind. (1.90–2.49 × 10<sup>8</sup>). The most abundant forest species (>10<sup>7</sup> individuals) were: Huet's Fulvetta (<em>Alcippe hueti</em>) with 2.84 × 10<sup>7</sup> ind., (range: 2.73–2.95 × 10<sup>7</sup>), Light-vented Bulbul (<em>Pycnonotus sinensis</em>) with 1.13 × 10<sup>7</sup> ind. (1.07–1.20 × 10<sup>7</sup>), Swinhoe's White-eye (<em>Zosterops simplex</em>) with 1.13 × 10<sup>7</sup> ind. (1.09–1.17 × 10<sup>7</sup>), and Red-whiskered Bulbul (<em>Pycnonotus jocosus</em>) with 1.01 × 10<sup>7</sup> ind. (9.66–10.47 × 10<sup>6</sup>). The total number of waterbirds in Guangdong was estimated to be 4.37 × 10<sup>7</sup> ind. (3.38–5.75 × 10<sup>7</sup>). The most abundant waterbirds (>10<sup>6</sup> individuals) were Black-headed Gull (<em>Chroicocephalus ridibundus</em>) with 6.35 × 10<sup>6</sup> ind. (5.48–7.36 × 10<sup>6</sup>), Pied Avocet (<em>Recurvirostra avosetta</em>) with 5.56 × 10<sup>6</sup> ind. (3.75–8.24 × 10<sup>6</sup>), and Little Egret (<em>Egretta garzetta</em>) with 5.01 × 10<sup>6</sup> ind. (4.19–6.00 × 10<sup>6</sup>). The densities and abundances of the 41 species listed as threatened in IUCN (higher than NT) or Chinese National Protected lists (higher than II) were evaluated, of which the population sizes of nine species were estimated for the first time in Guangdong. Moreover, all 41 species' average densities significantly declined from 2012 to 2017 in Nanling National Natural Reserve, Guangdong.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100305"},"PeriodicalIF":1.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145319604","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}
Pub Date : 2025-09-26DOI: 10.1016/j.avrs.2025.100304
Chenyang Ding , Jiaqi Cai , Yuandong Hu , Yuxuan Liang
Urban parks are essential habitats for birds in densely built environments. However, most studies focus only on horizontal features, overlooking the role of integrated vertical structures. Using bird records from the China Bird Report (CBR) collected between 2020 and 2024, this study focused on major urban parks in Harbin, a cold high-latitude city in Northeast China. Using interpretable machine learning models, we assessed the impact of three-dimensional (3D) park features on bird species richness and identified key variables along with their nonlinear relationships. Subsequently, we grouped bird species by ecological traits and applied ordination analysis to assess their differential abundance responses to the 3D environmental characteristics of urban parks. Results showed that: (1) urban park 3D environmental features had a certain influence on bird richness, among which disturbance from built-up land and the coverage of commercial buildings were the most important factors; (2) different bird groups responded differently to the urban park 3D environmental features. Specifically, waterbirds and generalist birds preferred mixed habitats dominated by water, wetlands, and tall vegetation, and exhibited significant edge effects caused by built-up land disturbance. In contrast, forest birds were mainly affected by greenspace configuration. Although they showed tolerance to human disturbance, this trend may increase the risk of biotic homogenization. The study used a 3D environmental framework integrating horizontal and vertical dimensions to explore how bird diversity is shaped, providing detailed recommendations for biodiversity-sensitive park planning in Harbin.
{"title":"Modeling the effects of urban park 3D environmental features on bird diversity with interpretable machine learning: A case study of Harbin, northeastern China","authors":"Chenyang Ding , Jiaqi Cai , Yuandong Hu , Yuxuan Liang","doi":"10.1016/j.avrs.2025.100304","DOIUrl":"10.1016/j.avrs.2025.100304","url":null,"abstract":"<div><div>Urban parks are essential habitats for birds in densely built environments. However, most studies focus only on horizontal features, overlooking the role of integrated vertical structures. Using bird records from the China Bird Report (CBR) collected between 2020 and 2024, this study focused on major urban parks in Harbin, a cold high-latitude city in Northeast China. Using interpretable machine learning models, we assessed the impact of three-dimensional (3D) park features on bird species richness and identified key variables along with their nonlinear relationships. Subsequently, we grouped bird species by ecological traits and applied ordination analysis to assess their differential abundance responses to the 3D environmental characteristics of urban parks. Results showed that: (1) urban park 3D environmental features had a certain influence on bird richness, among which disturbance from built-up land and the coverage of commercial buildings were the most important factors; (2) different bird groups responded differently to the urban park 3D environmental features. Specifically, waterbirds and generalist birds preferred mixed habitats dominated by water, wetlands, and tall vegetation, and exhibited significant edge effects caused by built-up land disturbance. In contrast, forest birds were mainly affected by greenspace configuration. Although they showed tolerance to human disturbance, this trend may increase the risk of biotic homogenization. The study used a 3D environmental framework integrating horizontal and vertical dimensions to explore how bird diversity is shaped, providing detailed recommendations for biodiversity-sensitive park planning in Harbin.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100304"},"PeriodicalIF":1.7,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145218970","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}
Pub Date : 2025-09-23DOI: 10.1016/j.avrs.2025.100303
Xiaoqian Li , Zeru Gong , Na Zhu, Shuping Zhang
The rapid expansion of urbanization has led to widespread exposure of wild birds to intensive light at night (LAN). While previous studies have established LAN-induced cognitive impairment in birds, the underlying neurobiological mechanisms remain poorly understood. We hypothesized that LAN exposure impaired cognitive function of birds potentially through neurodegeneration, metabolic dysregulation and neuroinflammatory responses in the telencephalon. Using Zebra Finches (Taeniopygia guttata) as an avian model, under 16L:8D photoperiods, we compared associative learning and memory abilities and neurobiological parameters between experimental groups exposed to dim light at night (LAN) versus nocturnal darkness (CTR). Compared to the CTR birds, the LAN-exposed birds exhibited significantly lower learning and memory performances, reduced neuron density and simplified dendritic morphology in the telencephalons. The key energy metabolic substrates (cholic acid, CTP, D-mannose-6-phosphate) and neuroprotective agents (trehalose, menaquinone, L-gulono-1,4-lactone) in the telencephalons of LAN-exposed birds showed depletion, while oxidative stress markers (methionine sulfoxide) and inflammatory mediators (cis-gondoic acid) exhibited elevation. The neurotransmitter dopamine and histamine metabolic pathway were disrupted in the LAN-exposed birds. The microglias were activated with pro-inflammatory IL-1β and IL-6 levels increasing and anti-inflammatory IL-10 decreasing in the telencephalons of the LAN-exposed birds. These findings indicate a potential mechanistic pathway whereby dim light exposure at night can induce neuroinflammation through oxidative stress-mediated microglial activation, energy metabolism and neurotransmitter homeostasis disruption, ultimately leading to neurodegeneration in the telencephalons of birds.
{"title":"Effects of night lighting on avian cognitive function: Mechanisms involving neurodegeneration, metabolic dysregulation and neuroinflammatory responses","authors":"Xiaoqian Li , Zeru Gong , Na Zhu, Shuping Zhang","doi":"10.1016/j.avrs.2025.100303","DOIUrl":"10.1016/j.avrs.2025.100303","url":null,"abstract":"<div><div>The rapid expansion of urbanization has led to widespread exposure of wild birds to intensive light at night (LAN). While previous studies have established LAN-induced cognitive impairment in birds, the underlying neurobiological mechanisms remain poorly understood. We hypothesized that LAN exposure impaired cognitive function of birds potentially through neurodegeneration, metabolic dysregulation and neuroinflammatory responses in the telencephalon. Using Zebra Finches (<em>Taeniopygia guttata</em>) as an avian model, under 16L:8D photoperiods, we compared associative learning and memory abilities and neurobiological parameters between experimental groups exposed to dim light at night (LAN) versus nocturnal darkness (CTR). Compared to the CTR birds, the LAN-exposed birds exhibited significantly lower learning and memory performances, reduced neuron density and simplified dendritic morphology in the telencephalons. The key energy metabolic substrates (cholic acid, CTP, D-mannose-6-phosphate) and neuroprotective agents (trehalose, menaquinone, L-gulono-1,4-lactone) in the telencephalons of LAN-exposed birds showed depletion, while oxidative stress markers (methionine sulfoxide) and inflammatory mediators (cis-gondoic acid) exhibited elevation. The neurotransmitter dopamine and histamine metabolic pathway were disrupted in the LAN-exposed birds. The microglias were activated with pro-inflammatory IL-1β and IL-6 levels increasing and anti-inflammatory IL-10 decreasing in the telencephalons of the LAN-exposed birds. These findings indicate a potential mechanistic pathway whereby dim light exposure at night can induce neuroinflammation through oxidative stress-mediated microglial activation, energy metabolism and neurotransmitter homeostasis disruption, ultimately leading to neurodegeneration in the telencephalons of birds.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100303"},"PeriodicalIF":1.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145218969","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}
Pub Date : 2025-09-18DOI: 10.1016/j.avrs.2025.100300
Marcel M. Lambrechts , D. Charles Deeming
Numerous hypotheses predict associations between phenotype-associated breeder traits and reproductive success. In secondary cavity-nesting passerine birds, which have been investigated most, up to more than 90 parental characteristics have been linked to at least one field measure of breeding performance. However, within study populations, different parental traits, such as clutch size, first-egg date, egg size, nest architecture, plumage colour, adult morphometry, or song performance, are often weakly correlated across female and/or male breeders. Furthermore, many of these studies have been conducted outside the theoretical framework of the ‘Individual Optimisation Hypothesis’ of clutch size (IOH). IOH predicts that: (i) females with larger clutches will have larger broods at hatching and fledging compared to those with smaller clutches; and (ii) clutch size, which is adaptively adjusted to the parents' ability to rear nestlings, should always maximize the percentage of eggs producing fledglings so that variation in clutch size becomes disconnected from variation in breeding success. In this paper, we present the first detailed review of implications of IOH for parental characters other than clutch size. Our review covered 188 non-experimental studies and 1074 statistical results that examined how parental traits influence breeding success in Western Palearctic Great Tits (Parus major), Blue Tits (Cyanistes spp.), and flycatchers (Ficedula spp.). Clutch size explained one third of the variation in brood size at hatching and fledging within study populations. However, most parental characteristics associated weakly with the number of hatchlings or fledglings, likely because they did not correlate with clutch size. Overall, parental traits were poorly correlated with the proportion of hatchlings and fledglings per egg. We discuss why intraspecific variation in phenotype-associated breeder traits is often disconnected from interindividual differences in breeding success, and highlight the importance of underexplored research problems in avian breeding biology.
{"title":"Parental phenotypes and breeding performance: a review of non-experimental investigation in well-studied Western palearctic tits and flycatchers","authors":"Marcel M. Lambrechts , D. Charles Deeming","doi":"10.1016/j.avrs.2025.100300","DOIUrl":"10.1016/j.avrs.2025.100300","url":null,"abstract":"<div><div>Numerous hypotheses predict associations between phenotype-associated breeder traits and reproductive success. In secondary cavity-nesting passerine birds, which have been investigated most, up to more than 90 parental characteristics have been linked to at least one field measure of breeding performance. However, within study populations, different parental traits, such as clutch size, first-egg date, egg size, nest architecture, plumage colour, adult morphometry, or song performance, are often weakly correlated across female and/or male breeders. Furthermore, many of these studies have been conducted outside the theoretical framework of the ‘Individual Optimisation Hypothesis’ of clutch size (IOH). IOH predicts that: (i) females with larger clutches will have larger broods at hatching and fledging compared to those with smaller clutches; and (ii) clutch size, which is adaptively adjusted to the parents' ability to rear nestlings, should always maximize the percentage of eggs producing fledglings so that variation in clutch size becomes disconnected from variation in breeding success. In this paper, we present the first detailed review of implications of IOH for parental characters other than clutch size. Our review covered 188 non-experimental studies and 1074 statistical results that examined how parental traits influence breeding success in Western Palearctic Great Tits (<em>Parus major</em>), Blue Tits (<em>Cyanistes</em> spp.), and flycatchers (<em>Ficedula</em> spp.). Clutch size explained one third of the variation in brood size at hatching and fledging within study populations. However, most parental characteristics associated weakly with the number of hatchlings or fledglings, likely because they did not correlate with clutch size. Overall, parental traits were poorly correlated with the proportion of hatchlings and fledglings per egg. We discuss why intraspecific variation in phenotype-associated breeder traits is often disconnected from interindividual differences in breeding success, and highlight the importance of underexplored research problems in avian breeding biology.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100300"},"PeriodicalIF":1.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219565","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}
Pub Date : 2025-09-06DOI: 10.1016/j.avrs.2025.100299
Yuqi Sun , Changjian Fu , Yumeng Zhao , Zhiyang Ding , Miaomiao Lai , Zhongqiu Li
Recognition of heterospecific mobbing calls can occur through both innate and learned mechanisms, with the former often explained by two main hypotheses: the acoustic similarity hypothesis, which emphasizes shared acoustic features, and the phylogenetic conservatism hypothesis, which posits that closely related species may share innate decoding templates. However, it remains unclear whether phylogenetic relatedness alone can drive the recognition of unfamiliar mobbing calls, a question with important implications for understanding the evolution of interspecific communication and anti-predator strategies. We examined the recognition of unfamiliar mobbing calls in Masked Laughingthrushes (Pterorhinus perspicillatus) using playback experiments with three allopatric species' mobbing calls of Leiothrichidae family. Results revealed two key findings: (1) Masked Laughingthrushes exhibited mobbing responses to unfamiliar mobbing calls, though at significantly lower intensity compared to conspecific playbacks. (2) Phylogenetic relatedness significantly predicted mobbing intensity, independent of overall acoustic similarity. These findings improve our understanding of how birds like Masked Laughingthrush instinctively recognize mobbing calls from other species. We show phylogenetic relatedness rather than overall acoustic similarity may be a key to this innate ability. Species that share a common ancestor may possess similar built-in neural systems for decoding alarm signals. We suggest that future research needs to combine neurobiological techniques to determine how inherited biases and feature decoding system together guide variable bird communities to perceive heterospecific mobbing calls.
{"title":"Phylogenetic relatedness overshadows acoustic similarity to regulate responses toward unfamiliar mobbing calls in Masked Laughingthrushes","authors":"Yuqi Sun , Changjian Fu , Yumeng Zhao , Zhiyang Ding , Miaomiao Lai , Zhongqiu Li","doi":"10.1016/j.avrs.2025.100299","DOIUrl":"10.1016/j.avrs.2025.100299","url":null,"abstract":"<div><div>Recognition of heterospecific mobbing calls can occur through both innate and learned mechanisms, with the former often explained by two main hypotheses: the acoustic similarity hypothesis, which emphasizes shared acoustic features, and the phylogenetic conservatism hypothesis, which posits that closely related species may share innate decoding templates. However, it remains unclear whether phylogenetic relatedness alone can drive the recognition of unfamiliar mobbing calls, a question with important implications for understanding the evolution of interspecific communication and anti-predator strategies. We examined the recognition of unfamiliar mobbing calls in Masked Laughingthrushes (<em>Pterorhinus perspicillatus</em>) using playback experiments with three allopatric species' mobbing calls of Leiothrichidae family. Results revealed two key findings: (1) Masked Laughingthrushes exhibited mobbing responses to unfamiliar mobbing calls, though at significantly lower intensity compared to conspecific playbacks. (2) Phylogenetic relatedness significantly predicted mobbing intensity, independent of overall acoustic similarity. These findings improve our understanding of how birds like Masked Laughingthrush instinctively recognize mobbing calls from other species. We show phylogenetic relatedness rather than overall acoustic similarity may be a key to this innate ability. Species that share a common ancestor may possess similar built-in neural systems for decoding alarm signals. We suggest that future research needs to combine neurobiological techniques to determine how inherited biases and feature decoding system together guide variable bird communities to perceive heterospecific mobbing calls.</div></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":"16 4","pages":"Article 100299"},"PeriodicalIF":1.7,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049240","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}
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