Otis Tarda Research Articles

The expansion of olive groves is reducing habitat suitability for the Great Bustard Otis tarda and the Little Bustard Tetrax tetrax in Southern Spain: could Important Bird Areas (IBAs) reduce this expansion?

AbstractOlive groves in the Mediterranean basin have undergone a tremendous increase during the last two decades, with most of the new olive groves being planted on arable land. This conversion may affect habitat suitability for steppe birds, which are associated with arable land and other open-land habitats, such as natural pastures. In this work, we evaluate the presence of new olive groves in the distribution of the Great Bustard Otis tarda and the Little Bustard Tetrax tetrax in Southern Spain (the largest olive oil production zone in the world), and we compare the percentage of different land uses in 2000 and 2018 using data provided by the Corine Land Cover. From 2000 to 2018, new olive groves occupied 2.14 and 2.61% of the distribution areas of the Great Bustard and the Little Bustard, respectively. The decrease in arable land and the increase in permanent crops were the main drivers of the landscape composition changes during the study period. The fragmentation index of arable land was higher in 2018 than 2000. These changes in the landscape suggest a decrease in habitat availability and suitability for steppe birds that could affect the distribution and abundance of their populations. Moreover, there were no differences in the proportion of new olive groves planted inside and outside the limits of Important Bird Areas (IBAs) from 2000 to 2018, which were created to protect these steppe birds, thus suggesting that the management policy of the IBAs should be reviewed to prevent harmful land-use changes.

Otis tarda

This datasheet on Otis tarda covers Identity, Distribution.

基于动物适宜栖息地的北京市自然保护地保护成效评估

PDF HTML阅读 XML下载 导出引用 引用提醒 基于动物适宜栖息地的北京市自然保护地保护成效评估 DOI: 10.5846/stxb202109022475 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31872240）；国家林业和草原局项目（2021080323-1）；北京绿色生态空间保护空缺分析项目（2021XJL02） Assess the conservation effectiveness of the natural protected areas in Beijing based on the suitable habitat of wild animals Author: Affiliation: Fund Project: The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:栖息地是野生动物赖以生存的基础，明晰物种的适宜栖息地分布是切实加强野生动物保护、提高生物多样性保护成效的重要基础。北京市野生动植物资源丰富，也建立了一系列自然保护地以加强对野生动物的保护。当前亟需系统评估北京市现有自然保护地体系对野生动物适宜栖息地的保护成效，为未来北京市野生动物保护管理和自然保护地体系整合工作优化提供科学指导。研究选取了北京地区6个较为典型的野生动物为主要研究对象，包括黑鹳（Ciconia nigra）、褐马鸡（Crossoption mantchuricum）、大鸨（Otis tarda）、鸳鸯（Aix galericulata）、金雕（Aquila chrysaetos）和斑羚（Naemorhedus griseus），利用MaxEnt模型和ArcGIS的空间分析功能分析其适宜栖息地的分布；将自然保护地与适宜栖息地相叠加，识别其适宜栖息地的分布热点和保护空缺，进而评估了北京市现有自然保护地体系的保护成效。研究结果表明，6个研究物种在现有的自然保护地体系中均得到了不同程度的保护，其中褐马鸡的受保护率最高（92.82%），鸳鸯的受保护率最低（13.66%）。各类自然保护地的物种热点区覆盖率不同，风景名胜区类型覆盖率最高（14.74%）。6个物种适宜栖息地的热点区域总面积为280.01km2，保护空缺占热点区域总面积的49.45%，其中密云区、门头沟区和房山区的保护空缺面积最大。基于现有自然保护地体系对野生动物适宜栖息地的保护效率以及存在的空缺，建议因地制宜，采取扩大或合并现有自然保护地、增设新的自然保护地或营造微生境等方式来提升自然保护地的整体保护效率。研究结果可为北京市自然保护地的整合优化提供重要依据，为野生动物重要栖息地的识别与划定提供可行方案，并为加强野生动物的保护管理提供科学指导。 Abstract:Habitats are essential for the survival of wild animals, and clarifying the distribution of a species' suitable habitat can be helpful to strengthen wildlife conservation and to increase the conservation effectiveness for biodiversity. As the capital of China, Beijing holds abundant wild animals and the government has established different types of natural protected areas to provide the refuge for the wildlife. Nowadays, it is urgent to assess the effectiveness of these natural protected areas on the protection of habitats of the wild animals, which will provide scientific guidance to wildlife conservation management and integration of natural protected areas in Beijing. Based on the relative importance and the availability of the distribution data, we selected 6 typical wild animals in Beijing, i.e., Black stork (Ciconia nigra), Brown eared-pheasant (Crossoption mantchuricum), Great bustard (Otis tarda), Mandarin duck (Aix galericulata), Golden eagle (Aquila chrysaetos) and Chinese goral (Naemorhedus griseus), and collected the distribution data of these species through field investigations, open databases and literature. We then analyzed the suitable habitats using the MaxEnt model and spatial analysis function of ArcGIS. We also identified the hotspots and GAPs (GAP analysis) of these species' suitable habitats in Beijing. The results indicated that the natural protected areas covered various proportions of these animals' suitable habitats with a range from 13.66% (Mandarin duck) to 92.82% (Brown-eared pheasant). The total area of the suitable habitat hotspots was 280.01 km2, and mainly distributed in Miyun District, Yanqing District, Mentougou District and Fangshan District. However, the coverage of species hotspots differed among different natural protected areas, with it being highest in scenic spots (14.74%). The GAPs were responsible for 49.45% of the hotspots and mainly distributed in Miyun District, Mentougou District, Fangshan District, and the border of Miyun, Huairou and Yanqing. In particular, Miyun District, Mentougou District and Fangshan District held the largest areas of GAPs. Based on the distribution of the suitable habitats and the protection gaps, it is suggested to take suitable measures to improve the conservation effectiveness of the natural protected areas according to the local circumstances, and adopt different protection strategies for different protection objects, including expanding or merging some natural protected areas, establishing new natural protected areas, and creating micro-habitats. Our study provides feasible solutions for the identification and delineation of important wildlife habitats in Beijing, provides some scientific guidelines for the wildlife management and integration and optimization of the natural protected area system. 参考文献 相似文献 引证文献

黄河流域濒危物种保护热点区与保护空缺识别

黄河流域具有重要的生物多样性保护意义，通过研究珍稀濒危物种分布热点区可为生物多样性保护提供依据。选取70种濒危维管植物和陆生脊椎动物，综合多来源的分布数据，运用物种分布模型Maxent模拟物种分布区，结合自然地理区划，计算保护价值，进行热点区分析，并结合国家级自然保护区和国家公园体制试点区的分布情况进行空缺分析。研究结果显示，黄河流域濒危物种分布主要呈现出南高北低、集中于山地的特征，热点区包括秦岭区域、太行山区域、子午岭-六盘山区域、陇中高原至松潘高原、祁连山、贺兰山和沿黄湿地等。在区分自然地理区后，现有的国家级自然保护区和国家公园体制试点区覆盖了热点区面积的13.89%，保护空缺主要出现于子午岭南部、六盘山南部、松潘高原南部和拉脊山等。建议在推进黄河流域生态保护和高质量发展中将濒危物种热点区考虑在内，对黄河流域自然保护地体系进行优化，并针对黄河流域的三个自然地理分区提出了相应的保护建议。此外，研究发现，在进行热点区分析时，考虑自然地理区域划分，并综合多类群叠加和单一生物类群的分析结果进行统筹考虑，可能会更好满足生物多样性就地保护需求。;The Yellow River Basin has important biodiversity protection significance. Research on the distribution hotspots of rare and endangered species can provide a basis for biodiversity protection and establishing protected area system. In this study, 70 endangered species were selected, including 26 vascular plants and 44 terrestrial vertebrates. Distribution data from multiple sources of these species were integrated to provide distribution point samples for modeling. The species distribution model Maxent was used to simulate distribution areas. All the Maxent simulation results were superimposed according to different taxa and physical geographical regions, and we calculated the biodiversity conservation value for analyzing hot spots. the conservation gaps were analyzed by integrating the distribution layer of national nature reserves and national parks (pilot area). Results show that the distribution of endangered species in the Yellow River Basin is mainly high in the south, and is concentrated in the mountain areas. The hot spots include Qinling Mountains, Taihang Mountains, Ziwuling-Liupan Mountains, Longzhong Plateau to Songpan Plateau, Qilian Mountains, Helan Mountains, and wetlands along the Yellow River. After distinguishing the geographical regions, the existing national nature reserves and national parks (pilot area) cover 13.89% of the hot spots' area, and the protection gaps are mainly found in the southern Ziwuling Mountains, the southern Liupanshan Mountains, the southern Songpan Plateau and the Laki Mountains. It is suggested that the threatened species hotspots should be taken into account in ecological conservation and high-quality development planning of the Yellow River Basin, and the natural protected area system of the Yellow River Basin should be optimized. For three different physical geographical regions in Yellow River Basin, specific suggestions are put forward:in Qinghai-Tibet Alpine Region, the protected areas should be optimized and biodiversity survey should be strengthened; in Northwest Arid and Semi-arid Region, lakes in Ordos Plateau are worthy of the enhanced protection; in Eastern Monsoon Region, the leopard, great bustard and Baer's pochard should be considered as key species and put more efforts on their habitat protection. In addition, this study also shows that, when analyzing biodiversity hotspots, considering the division of physically geographic regions and combining the hot spot analysis results of multiple taxa and single taxa for overall consideration may be better for meeting the needs of biodiversity in-situ conservation.

Habitat suitability assessment for the Great Bustard Otis tarda tarda in Tacheng Basin, western China

The Great Bustard is afforded the highest category of protection in China. This species has disappeared from much of its former range, and identification of factors influencing habitat suitability can play a key role in development of conservation plans. We used distance sampling and interviews to census Great Bustards in the Tacheng Basin of western China in October from 2014 to 2016, and obtained 210 occurrence points. We then used high-resolution species distribution models to explore the role of 16 environmental variables, including a novel high-resolution contemporary climate dataset, in habitat suitability. Our ensemble model classifies approximately 3,885 km 2 , or 9.9% of our study area in the most suitable and moderately suitable categories. These suitable areas are distributed primarily in the north of our study area, in farmlands along the southern slope of Talbahetai Mountain, and to a lesser degree along the eastern slope of Balluk Mountain. The variables which contributed most significantly to habitat suitability include distance to county highway, elevation, distance to field edge, and mean summer temperature. We propose reducing disturbance associated with roads by conducting awareness campaigns among local residents and creating campaigns and policies to promote responsible bird photography. Given the important role of farmlands to Great Bustards, we recommend planting compatible crops and establishing a Great Bustard protection demonstration area to implement and inform others about measures to improve farmland habitat for Great Bustards.

The gut microbiota of wild wintering great bustard (Otis tarda dybowskii): survey data from two consecutive years.

BackgroundThe composition of the intestinal microbiota plays a significant role in modulating host health. It serves as a sensitive evaluation indicator and has substantial implications in protecting endangered species. Great Bustards are typical farmland-dependent wintering birds that are highly susceptible to the interference of human activities. However, information regarding their gut microbiota remains scarce.MethodsTo ensure a comprehensive analysis of this crucial data, we collected fecal samples from wild Great Bustards at their wintering habitat for two consecutive years. High-throughput sequencing of the 16S rRNA gene was subsequently applied to characterize their core gut microbiota and determine whether the gut microbial composition was similar or varied interannually.ResultsThe gut microbiota of the Great Bustard was primarily comprised of four phyla: Firmicutes (82.87%), Bacteroidetes (7.98%), Proteobacteria (4.49%), and Actinobacteria (3.67%), accounting for 99.01% of the microbial community in all samples. Further analysis revealed 22 genera of core microbes and several pathogens. Notably, there were no significant differences in the alpha-diversity and beta-diversity between the two sample groups from different years.ConclusionsThis study provides essential information for assessing the health and developing targeted protective measures of this threatened species.

Metabarcoding insights into the diet and trophic diversity of six declining farmland birds

Knowledge of feeding ecology of declining species, such as farmland birds, is essential to address their conservation requirements, especially when their habitats are suffering important reductions of trophic resources. In this study, we apply a metabarcoding approach to describe the diet composition of six of the most significant farmland birds inhabiting European cereal pseudo-steppes: little bustard, great bustard, pin-tailed sandgrouse, black-bellied sandgrouse, red-legged partridge, and common quail. We further studied seasonal diet variations (autumn to spring) in all species but the common quail, whose diet was studied during spring and summer. We show that study species´ diets mostly consisted of plants, although in the case of little bustard and great bustard arthropods are also highly relevant. Among arthropods, we found high proportions of thrips, arachnids, and springtails, which were previously unreported in their diet, and some taxa that could be used as antiparasitic food. Moreover, we report that little bustard’s diet is the least rich of that of all studied species, and that diet of all these species is less diverse in winter than in autumn and spring. Diet composition of these declining species supports the importance of natural and semi-natural vegetation and landscape mosaics that can provide a wide variety of arthropods, plants, and seeds all year-round.

Alfred Newton’s second-hand histories of extinction: hearsay, gossip, misapprehension (William T. Stearn Student Essay Prize 2020)

The study of extinction was rooted in Victorian naturalists’ practices of observation and collection, but presented a challenge to the discipline’s increasing emphasis on empiricism and precision. This paper traces the role of witness testimony and hearsay accounts in early studies of extinction, as preserved in the notebooks of Cambridge zoology professor, Alfred Newton. Beginning in 1850s, Newton and his collaborators sought to trace the histories of suspected extinct species such as the British great bustard and the great auk of Iceland. With its subject absent by definition, the study of extinction relied on hearsay and rumour as well as evidence gleaned from past published accounts. Through methodical attempts to collate diverse and contradictory sources, from eyewitnesses to newspapers to local folklore and gossip, Newton demonstrated the inextricability of human activities from the practice of studying extinction. These attempts to resolve social evidence into scientific certainty were time and again frustrated by the uncertain epistemic status of his sources.

Predicting the potential distribution of wintering Asian Great Bustard (Otis tarda dybowskii) in China: Conservation implications

Changes in future climate will alter the geographic distributions of many species. Species distribution models have evolved as a powerful tool for predicting potential species distributions and assessing habitat suitability. The Asian Great Bustard (Otis tarda dybowskii), a long-distance migratory bird, is listed as a globally threatened species and is highly dependent on farmlands during the wintering period. In this study, 78 occurrence points and 15 environmental variables were used to estimate the potential distribution under current conditions and four future climate scenarios by using the maximum entropy model. With current climatic conditions, the highly suitable areas of wintering Asian Great Bustard in China were mainly concentrated on the Northeast Plain, Guanzhong Plain, and North China Plain (33–48° N, 109–127° E). Under future climatic scenarios, the geographic distribution of wintering Asian Great Bustard would remain stable, and the total area of suitable habitats would increase to varying degrees until the end of this century. Our results can be used to define highly suitable areas for conservation management plans for this threatened species.

Taxonomic and ecological composition of the native groupings of the birds of the dry steppe zone of Ukraine

The classifications of the grouping of the birds reflect the faunistic or the ecological position of the species in certain habitats and landscapes. Most of them consider the species diversity of the birds of the studied regions in general, including synanthropic, invasive and widespread species. This approach prevents singling out the habitats which are important for supporting the existence of native (or autochtonous) species and their groupings. Native groupings of the birds in the dry steppe zone of Ukraine are almost not studied despite the rapid contraction in the range and population of most component species, especially Anthropoides virgo, Otis tarda, Tetrax tetrax and Burhinus oedicnemus. The definition of the taxonomic and the ecological composition of these grouping will help in understanding the strategy of the reproduction and the protection of native avifauna. In connection with this, the faunistic-topomorphic classification of native birds in the dry steppes zone of Ukraine according to the following scheme is proposed: ornithofaunistic complex (by priority landscapes and habitats) – the place of the feeding (by priority substrate on/in which a species’ diet is extracted) – the nesting place (by the priority substrate of the location of the nest for nesting individuals) – the place of rest (the priority substrate where non-nesting individuals rest). The classification is aimed at the definition of the general requirements of native birds and their groupings in terms of the landscapes and the habitats which provide the conditions for their preservation and the protection in the researched region. It has been determined that in the south of Ukraine 33 nesting species are dry-steppe autochthons (18.3% of nesting species of the region), of which 18 species form the ornithofaunistic complex of dry steppes (Buteo rufinus, Perdix perdix, Anthropoides virgo, Otis tarda, Tetrax tetrax, Burhinus oedicnemus, Glareola nordmanni, Galerida cristata, Calandrella cinerea, C. rufescens, Melanocorypha calandra, Anthus campestris, Motacilla feldegg, Saxicola rubetra, S. torquata, Oenanthe oenanthe, Oe. isabellina, Emberiza melanocephala), and 15 species form the complex of the sea coast (Phalacrocoraх aristotelis, Phoenicopterus roseus, Tadorna ferruginea, T. tadorna, Mergus serrator, Charadrius alexandrinus, Recurvirostra avosetta, Larus ichthyaetus, L. melanocephalus, L. genei, L. cachinnans, L. michahellis, Gelochelidon nilotica, Hydroprogne caspia, Thalasseus sandvicensis). The above-mentioned species are mainly xerophiles (54.6% of species) and hygrophils (24.2% of species), and they are in the most threatened position because they feed, nest and rest mainly or exclusively on the soil surface. According to the proposed classification, native birds of dry steppes require: for xerophiles – areas of soil without vegetation or with rarefied low grass, which does not prevent birds from moving freely, searching and obtaining food, leading their chicks, looking over their territories; for hygrophiles – shallow water bodies with islands, surface vegetation, shallows, adjacent meadows and salt-marshes; for dendrophiles – single shrubs and trees or small groves; for most xerophiles and dendrophiles – fresh or slightly saline water bodies for drinking. Unfortunately, in the protected natural territories of the researched region, most native birds do not have this combination of the above-mentioned habitats, which are simultaneously suitable for feeding, nesting and resting.

High bird mortality due to power lines invokes urgent environmental mitigation in a tropical desert

Electricity supply lines through wildlife habitats can adversely affect biodiversity, yet lack of evidence impedes their mitigation in tropical developing countries. We assessed power line induced bird mortality in 4200 km2 area of the Thar desert, India during 2017–18. We searched for carcasses in 2000 × 60 m2 belts along 40 randomly selected power lines over six multi-season surveys, and in 20 control transects that were surveyed once. We experimentally corrected for count biases by estimating persistence and detection probabilities of 88 fresh carcasses, using Kaplan-Meier survival analysis and binomial GLM, respectively. Scaling mortality by power line crossings of bird families, we examined the influence of group traits on vulnerability, using GLM. We examined the effect of power line mortality on population viability of the Critically Endangered great Indian bustard. We found 289 carcasses of >40 species at power lines and none at control transects. As expected, carcass persistence time and detectability were lower for small birds (<100 g) than large birds (>1000 g). Bias-adjusted mortality was estimated at 3.05 carcasses (95% CI 0.82–6.03) and 5.97 (2.5–10.50) carcasses km−1 month−1 for <33 kV and ≥33 kV lines, respectively. Mortality was positively related to number of wires. Large-bodied and ground-dwelling families were most vulnerable to power line mortality. We estimated 87,966 (SE 25,701) bird mortalities per year in the study area. These findings bear global conservation implications since the Thar desert supports 14 Threatened and 65 migratory species of the Central Asian Flyway. The population viability analysis revealed that the great Indian bustard is at imminent risk of extinction due to power line mortality, and calls for urgent mitigation of overhead power cables and the avoidance of future overhead installations in bustard habitat.

Current status of Great Bustard Otis tarda in Turkey: population size, distribution, movements, and threats

SummaryThe Great Bustard Otis tarda is a globally threatened species with populations inhabiting the steppe zones of Turkey. In recent decades, its populations in Turkey have suffered severe declines in range and size. Although the remaining populations are in urgent need of protection, there has been no national-scale study on the species since 2009, and huge information gaps remain concerning its range, abundance, and movements in the country. Here, we combined data from five years of fieldwork together with all available sight and literature records to present up-to-date estimates of distribution and population size in Turkey, to better understand its movement patterns, to reveal its recent and historical population changes, and to assess its national extinction risk and threats. We find that the species’ breeding population has shrunk by 20–29% over the last five years, and there are only 559–780 breeding Great Bustards in Turkey distributed in two discrete subpopulations. Comparison with historical records shows that the species’ range has shrunk by at least 60% since the beginning of the 20th century. We suggest possible migratory routes within and through Turkey and that Turkey might have a higher regional importance for the species than previously thought. Illegal hunting, agricultural intensification, shift to irrigated crops, overgrazing, collision with powerlines, and disturbance are the most severe threats to the species in Turkey. Our national Red List assessment yields an Endangered categorisation. Further studies are needed to understand the metapopulation structure and movements of the species and to conserve its remaining populations in Turkey.

Diet-induced microbiome shifts of sympatric overwintering birds.

Gut microbiota have a significant impact on host physiology and health, and host genetics and diet are considered as two important factors, but it is difficult to discriminate the influence of each single factor (host or diet) on gut microbiota under natural conditions. Moreover, current studies of avian microbiota mainly focus on domestic or captive birds, and it is still uncertain how host and diet take part in changing avian gut microbiota composition, diversity, and function in the wild. Here, high-throughput sequencing of 16S rRNA was used to identify the gut microbiota communities for sympatric wintering Great Bustards and Common Cranes at different diets. The results showed that 8.87% operational taxonomic units (OTUs) were shared among all sampling birds; in contrast, 39.43% of Kyoto Encyclopedia of Genes and Genomes (KEGG) functional pathways were common among all individuals, indicating the existence of gut microbiota conservatism both in microbiota structure and function. Microbiota abundance and diversity differed between Great Bustards and Common Cranes in a specific wintering site, and microbiota variation was detected for the same host species under two different sites, suggesting that the change of gut microbiota was induced by both host and diet. Furthermore, we found that changes of both microbial communities and functional pathways were larger between hosts than those between diets, which revealed that host might be the dominant factor determining microbiota characteristics and function, while diet further drove the divergence of gut microbiota. Gut microbiota functions appeared to be more conserved than bacterial community structure, indicating that different bacteria may function in a similar way, while microbiota OTU diversity might not be necessarily associated with functional diversity. With diet shifting, gut microbiota changed both in terms of microbial communities and functional pathways for the sympatric birds, which implies that avian habitats and their physiological microbiota would be influenced by different farmland management regimes. KEY POINTS: • Gut microbiota can be shaped by both diets and hosts in sympatric species. • Host was the dominant factor shaping the gut microbiota communities and functional pathways. • Gut microbiota were conservative both in structure and in function, but more conservative in function.

Antiparasitic Effects of Potentially Toxic Beetles (Tenebrionidae and Meloidae) from Steppe Zones.

Arthropods and specifically beetles can synthesize and/or sequester metabolites from dietary sources. In beetle families such as Tenebrionidae and Meloidae, a few studies have reported species with toxic defensive substances and antiparasitic properties that are consumed by birds. Here we have studied the antiparasitic activity of extracts from beetle species present in the habitat of the Great Bustard (Otis tarda) against four pathogen models (Aspergillus niger, Meloidogyne javanica, Hyalomma lusitanicum, and Trichomonas gallinae). The insect species extracted were Tentyria peiroleri, Scaurus uncinus, Blaps lethifera (Tenebrionidae), and Mylabris quadripunctata (Meloidae). M. quadripunctata exhibited potent activity against M. javanica and T. gallinae, while T. peiroleri exhibited moderate antiprotozoal activity. The chemical composition of the insect extracts was studied by gas chromatography coupled with mass spectrometry (GC-MS) analysis. The most abundant compounds in the four beetle extracts were hydrocarbons and fatty acids such as palmitic acid, myristic acid and methyl linoleate, which are characteristic of insect cuticles. The presence of cantharidin (CTD) in the M. quadripunctata meloid and ethyl oleate (EO) in T. peiroleri accounted for the bioactivity of their extracts.

Devil is in the detail: behaviorally explicit habitat selection by the Critically Endangered great Indian bustard

Habitat management to accommodate ecological needs of threatened species can help abate biodiversity decline. Some species require contrasting microhabitats for different functions, and may prefer patches with ample, diverse microhabitats. We examined this problem for the Critically Endangered great Indian bustard Ardeotis nigriceps in 175 km2 breeding habitat in Kachchh, India. We developed behaviorally explicit resource selection functions (RSFs) by comparing used vs. available microhabitats using binomial generalized linear models that tested hypothesized habitat responses in an information theoretic framework. We identified suitable resource units based on fitted RSF values. We examined if availability of complementary resource units influenced density/usage at the patch level, using line transect distance sampling. Birds preferred agro-vegetation mixture, grassland, high fruit abundance and intermediate grazing density, and they avoided Prosopis thickets for foraging. They preferred moderately tall sward for day resting but shorter sward and less Prosopis for roosting. Nesting females preferred grasslands with relatively tall sward and abundant insects, while displaying males preferred grasslands with shorter sward, far from settlements. Thus, microhabitat selection differed between behaviors and differed from habitat availability. The RSF without behavioral segregation failed to capture these nuances and was non-informative for habitat management. Density/usage at the patch level was correlated with the availability of complementary microhabitats. Thus, protected area management to accommodate diverse life-history requirements may reduce species’ movements over large hostile landscapes and associated mortality. Overall, species requiring complementary microhabitats will benefit from management that promotes habitat heterogeneity. However, habitat use analysis based on behaviorally inexplicit occurrence cannot capture the habitat quality of such species.

Counting Results of Great Bustard (Otis tarda, Linnaeus, 1758) Between 2013-2020 in Eskişehir, Kütahya and Afyonkarahisar provinces

The Great Bustard (Otis tarda, Linneaus 1758) is a bird species categorized as “Least Concern” in Europe and “Vulnerable” in the world by the IUCN and listed in both CITES and the Bern Convention Annex II. According to the latest estimates, Turkey’s population makes up only 1-2% of the global population, which is represented by 44.000-57.000 individuals. This population study was carried out in 7 different locations in Eskişehir, Kütahya, and Afyonkarahisar provinces between March 2013 and January 2020. In summary, the surveyed areas were recorded as having a total wintering population of 205 individuals, a total breeding population of 100 individuals, and a total summering population of 70 individuals. The surveyed areas represent an average of 17-29% of Turkey’s population in wintering period, an average of 8-14% of Turkey’s population in breeding period, and an average of 6-10% of Turkey’s population in summering period. Urgent implementation of protective measures is required to prevent the population decline of the Great Bustard within the study areas. Detailed ethological studies on the species are recommended as a means of creating new measures to not only stop population decline but to promote population growth to healthy levels.

West Nile and Usutu virus infections in wild birds admitted to rehabilitation centres in Extremadura, western Spain, 2017–2019

West Nile virus (WNV) is an emerging flavivirus transmitted generally by mosquitoes of Culex genus. It is maintained in an enzootic life cycle where birds act as reservoir hosts. Humans and horses are also susceptible to infection, and occasionally, they suffer from neurological complications. However, they do not transmit the virus to other vectors, behaving as dead-end hosts. Sporadic WNV outbreaks observed in horses and wild birds from Extremadura (western Spain) during 2016 and 2017 seasons prompted to carry out this survey in wild birds, focused on specimens coming from two wildlife rehabilitation centres. Between October 2017 and December 2019, samples from 391 wild birds, belonging to 56 different species were collected and analysed in search of evidence of WNV infection. The analysis of serum samples for WNV-specific antibodies by ELISA, whose specificity was subsequently confirmed by virus-neutralisation test (VNT) showed positive results in 18.23 % birds belonging to 18 different species. Pelecaniformes (33.33 %), Accipitriformes (25.77 %) and Strigiformes (22.92 %) orders had the higher seroprevalences. Remarkably, WNV-specific antibodies were found in a black stork for the first time in Europe. Analysis by real time RT-PCR in symptomatic birds confirmed the presence of WNV lineage 1 RNA in griffon vulture and little owls. Specificity analysis of ELISA positive and doubtful sera was performed by differential VNT titration against WNV and two other cross-reacting avian flaviviruses found in Spain: Usutu virus (USUV) and Bagaza virus (BAGV). Only four samples showed USUV-specific antibodies (1.04 %) corresponding to three species: Eurasian eagle-owl, griffon vulture and great bustard (first detection in Europe) whereas no samples were found reactive to BAGV. Differential VNT yielded undetermined flavivirus result in 16 samples (4.17 %). This is the first study carried out on wild birds from Extremadura (western Spain). It highlights the widespread circulation of WNV in the region and its co-circulation with USUV.

Effects of Sex and Diet on Gut Microbiota of Farmland-Dependent Wintering Birds.

Gut microbiota plays an important role for bird biological and ecological properties, and sex and diet may be important intrinsic and extrinsic factors influencing gut microbial communities. However, sex difference of gut microbiota has been rarely investigated in free-living birds, and it remains unclear how sex and diet interactively affect avian gut microbiota composition and diversity, particularly under natural conditions. Here we used non-invasive molecular sexing technique to sex the fecal samples collected from two wintering sites of Great Bustard, which is the most sexually dimorphic among birds, as well as a typical farmland-dependent wintering bird. High-throughput sequencing of 16S was applied to identify the gut microbiota communities for both sexes under two diets (wheat_corn and rice_peanut). The results showed that 9.74% of common microbiota taxa was shared among four groups (sex vs. diet), revealing the conservatism of gut microbiota. Microbiota diversity, composition and abundance varied on different diets for male and female Great Bustards, suggesting that the gut microbiota was interactively influenced by both sex and diet. Under the wheat_corn diet, females had higher abundances of the phylum Verrucomicrobia than males, but lower Bacteroidetes and Firmicutes compared to males; meanwhile, the microbiota diversity and evenness were higher for males than females. In contrast, under the rice_peanut diet, females were more colonized by the phylum Firmicutes than males, but less by the phylum Bacteroidetes; while males had lower microbiota diversity and evenness than females. This study investigated the impacts of sex and diet on microbiota of Great Bustards, and highlights the need of new studies, perhaps with the same methodology, taking into account bird ages, flock size, breeding or health status, which will contribute to the understanding of ecology and conservation of this vulnerable species.

Models for human porphyrias: Have animals in the wild been overlooked?: Some birds and mammals accumulate significant amounts of porphyrins in the body without showing the injurious symptoms observed in human porphyrias.

Humans accumulate porphyrins in the body mostly during the course of porphyrias, diseases caused by defects in the enzymes of the heme biosynthesis pathway and that produce acute attacks, skin lesions and liver cancer. In contrast, some wild mammals and birds are adapted to accumulate porphyrins without injurious consequences. Here we propose viewing such physiological adaptations as potential solutions to human porphyrias, and suggest certain wild animals as models. Given the enzymatic activity and/or the patterns of porphyrin excretion and accumulation, the fox squirrel, the great bustard and the Eurasian eagle owl may constitute overlooked models for different porphyrias. The Harderian gland of rodents, where large amounts of porphyrins are synthesized, presents an underexplored potential for understanding the carcinogenic/toxic effect of porphyrin accumulation. Investigating how these animals avoid porphyrin pathogenicity may complement the use of laboratory models for porphyrias and provide new insights into the treatment of these disorders.

Effectiveness of the European Natura 2000 network at protecting Western Europe's agro-steppes

Assessing progress towards achieving conservation targets is required for all countries committed to the Convention on Biological Diversity. The Natura 2000 network is the largest protected area network in the world and was created to protect Europe's threatened species and habitats, often requiring active management. This study assesses the effectiveness of areas classified under the EU Birds Directive at protecting Western Europe's agro-steppes, the last remnants of suitable habitat for several endangered bird species. We quantify agro-steppe habitat change in the last 10 years using high-resolution aerial images of 21 Special Protection Areas and surrounding areas. The selected SPAs hold one third of the global population of great bustards Otis tarda, a flagship conservation species. Agro-steppe area losses occurred across all sites surveyed but were 45% lower inside Natura 2000 compared to non-protected areas. Natura 2000 sites still lost over 35,000 ha of agro-steppe habitat in 10 years, an area that could hold more than 500 great bustards. These low yield farmlands are being converted predominately to permanent and irrigated crops. At the current rate of habitat conversion, agro-steppes could be reduced to 50% of the present area during the next century. Moreover, the greater conversions outside protected sites may transform the remaining agro-steppes into isolated “islands” with low population connectivity. Our study on agro-steppes illustrates the relevant contribution of Natura 2000 at protecting Europe's key habitats, but also highlights crucial insufficiencies that still need to be addressed to achieve the CBD conservation targets and halt biodiversity loss.