Identifying habitat conservation priorities and gaps for migratory shorebirds and waterfowl in California

Conservation of migratory shorebirds and waterfowl presents unique challenges due to extensive historic loss of wetland habitats, and current reliance on managed landscapes for wintering and migratory passage. We developed a spatially-explicit approach to estimate potential shorebird and waterfowl densities in California by integrating mapped habitat layers and statewide bird survey data with expert-based habitat rankings. Using these density estimates as inputs, we used the Marxan site-selection program to identify priority shorebird and waterfowl areas at the ecoregional level. We identified 3.7 million ha of habitat for shorebirds and waterfowl, of which 1.4 million ha would be required to conserve 50% of wintering populations. To achieve a conservation goal of 75%, more than twice as much habitat (3.1 million ha) would be necessary. Agricultural habitats comprised a substantial portion of priority areas, especially at the 75% level, suggesting that under current management conditions, large areas of agricultural land, much of it formerly wetland, are needed to provide the habitat availability and landscape connectivity required by shorebird and waterfowl populations. These habitats were found to be largely lacking recognized conservation status in California (96% un-conserved), with only slightly higher levels of conservation for priority shorebird and waterfowl areas. Freshwater habitats, including wetlands and ponds, were also found to have low levels of conservation (67% un-conserved), although priority shorebird and waterfowl areas had somewhat higher levels of conservation than the state as a whole. Conserving migratory waterfowl and shorebirds will require a diversity of conservation strategies executed at a variety of scales. Our modeled results are complementary with other approaches and can help prioritize areas for protection, restoration and other actions. Traditional habitat protection strategies such as conservation easements and fee acquisitions may be of limited utility for protecting and managing significant areas of agricultural lands. Instead, conservation strategies focused on incentive-based programs to support wildlife friendly management practices in agricultural settings may have greater utility and conservation effectiveness.     

Effects of Local and Landscape Variables on Wetland Bird Habitat Use During Migration Through the Rainwater Basin

ABSTRACT Staging areas and migratory stopovers of wetland birds can function as geographic bottlenecks; common dependence among migratory wetland bird species on these sites has major implications for wetland conservation. Although 90% of playa wetlands in the Rainwater Basin (RWB) region of Nebraska, USA, have been destroyed, the area still provides essential stopover habitat for up to 10 million waterfowl each spring. Our objectives were to determine local (within wetland and immediate watershed) and landscape-scale factors influencing wetland bird abundance and species richness during spring migration at RWB playas. We surveyed 36–40 playas twice weekly in the RWB and observed approximately 1.6 million individual migratory wetland birds representing 72 species during spring migrations 2002–2004. We tested a priori hypotheses about whether local and landscape variables influenced overall species richness and abundance of geese, dabbling ducks, diving ducks, and shorebirds. Wetland area had a positive influence on goose abundance in all years, whereas percent emergent vegetation and hunting pressure had negative influences. Models predicting dabbling duck abundance differed among years; however, individual wetland area and area of semipermanent wetlands within 10 km of the study wetland consistently had a positive influence on dabbling duck abundance. Percent emergent vegetation also was a positive predictor of dabbling duck abundance in all years, indicating that wetlands with intermediate (50%) vegetation coverage have the greatest dabbling duck abundance. Shorebird abundance was positively influenced by wetland area and number of wetlands within 10 km and negatively influenced by water depth. Wetland area, water depth, and area of wetlands within 10 km were all equally important in models predicting overall species richness. Total species richness was positively influenced by wetland area and negatively influenced by water depth and area of semipermanent wetlands within 10 km. Avian species richness also was greatest in wetlands with intermediate vegetation coverage. Restoring playa hydrology should promote intermediate percent cover of emergent vegetation, which will increase use by dabbling ducks and shorebirds, and decrease snow goose (Chen caerulescens) use of these wetlands. We observed a reduction in dabbling duck abundance on wetlands open to spring snow goose hunting and recommend further investigation of the effects of this conservation order on nontarget species. Our results indicate that wildlife managers at migration stopover areas should conserve wetlands in complexes to meet the continuing and future habitat requirements of migratory birds, especially dabbling ducks, during spring migration.     

湿地公园鸟类栖息地营建研究——以北京琉璃河湿地公园为例

北京地区处于全球候鸟东亚-澳大利西亚的迁徙路线上,是候鸟重要的迁徙路线,近些年,随着人为活动的影响,该区生境破碎化问题愈发突出,直接威胁着本地鸟种和过境迁徙鸟类的生存。为达到保护鸟类多样性的目的,需开展相应的栖息地恢复工作。不同生态类群的鸟类对栖息地有着不同的要求,相同鸟种在不同空间、季节和生活期对栖息地的选择也有着不同的特点。因而,鸟类栖息地恢复应针对目标鸟种根据其繁殖特点、巢位空间分布、食性特点、活动空间特点等进行规划营造。以北京房山琉璃河湿地公园为例,针对项目所在区域的鸟类分布特征,确定目标恢复鸟种,结合项目区现场条件,围绕目标鸟种对于栖息地水系、植被等方面的需求,从岸线重塑、水深设计、植物配置、生态鸟岛等方面规划设计鸟类栖息地修复措施。     

Seasonal abundance and habitat use of bird species in and around Wondo Genet Forest,south‐central Ethiopia

The habitat use and seasonal migratory pattern of birds in Ethiopia is less explored as compared to diversity studies. To this end, this study aimed at investigating the patterns of distribution related to seasonality and the effect of habitat characteristics (elevation, slope, and average vegetation height) on habitat use of birds of Wondo Genet Forest Patch. A stratified random sampling design was used to assess the avian fauna across the four dominant habitat types found in the study area: natural forest, wooded grassland, grassland, and agroforestry land. A point transect count was employed to investigate avian species richness and abundance per habitat type per season. Ancillary data, such as elevation above sea level, latitude and longitude, average vegetation height, and percent slope inclination, were recorded with a GPS and clinometers per plot. A total of 33 migratory bird species were recorded from the area, of which 20 species were northern (Palearctic) migrants while 13 were inter‐African migrants. There was a significant difference in the mean abundance of migratory bird species between dry and wet seasons (t = 2.13, p = .038, df = 44). The variation in mean abundance per plot between the dry and wet seasons in the grassland habitat was significant (t = 2.35, p = .051, df = 7). In most habitat types during both dry and wet seasons, omnivore birds were the most abundant. While slope was a good predictor for bird species abundance in the dry season, altitude and average vegetation height accounted more in the wet season. The patch of forest and its surrounding is an important bird area for migratory, endemic, and global threatened species. Hence, it is conservation priority area, and the study suggests that conservation coupled with ecotourism development is needed for its sustainability.     

Predicted Effect of Landscape Position on Wildlife Habitat Value of Conservation Reserve Enhancement Program Wetlands in a Tile‐drained Agricultural Region

Justification for investment in restored or constructed wetland projects are often based on presumed net increases in ecosystem services. However, quantitative assessment of performance metrics is often difficult and restricted to a single objective. More comprehensive performance assessments could help inform decision‐makers about trade‐offs in services provided by alternative restoration program design attributes. The primary goal of the Iowa Conservation Reserve Enhancement Program is to establish wetlands that efficiently remove nitrates from tile‐drained agricultural landscapes. A secondary objective is provision of wildlife habitat. We used existing wildlife habitat models to compare relative net change in potential wildlife habitat value for four alternative landscape positions of wetlands within the watershed. Predicted species richness and habitat value for birds, mammals, amphibians, and reptiles generally increased as the wetland position moved lower in the watershed. However, predicted average net increase between pre‐ and post‐project value was dependent on taxonomic group. The increased average wetland area and changes in surrounding upland habitat composition among landscape positions were responsible for these differences. Net change in predicted densities of several grassland bird species at the four landscape positions was variable and species‐dependent. Predicted waterfowl breeding activity was greater for lower drainage position wetlands. Although our models are simplistic and provide only a predictive index of potential habitat value, we believe such assessment exercises can provide a tool for coarse‐level comparisons of alternative proposed project attributes and a basis for constructing informed hypotheses in auxiliary empirical field studies.     

Distribution of waterfowl in the wetland of Northern Nigeria

Agbelusi, E.A. & Afolayan, T.A. 2000. Distribution of waterfowl in the wetland of Northern Nigeria. Ostrich 71 (1 & 2): 73.

Nigeria with a land area of 923 850 km² has approximately 24 000 km² of wetland. These wetlands are scattered all over the country and include the man-made lakes. The wetlands of northern Nigeria are important breeding sites for Afrotropical duck and also serve as the winter refuge for Palearctic birds from Europe. About 13 sites have been identified as the actual habitat and concentration points for waterfowl in the wetlands of northern Nigeria. Among these areas, the Hadeija-Nguru wetland represents one of the most productive and ecologically significant wetlands in Nigeria. This area supports about 58 000 waterbirds, belonging to about 376 species, which consist mostly of Palearctic and Afrotropical migratory birds. Some of the important bird species that are associated with the wetland of northern Nigeria are Black Crowned Crane, Pintail, White Pelican, White-faced Tree Duck, Knob-billed Goose, Spur-winged Goose, Gull-billed Tern and Saddle-billed Stork. The paper also discusses the management implications for waterfowl conservation and tourism in Nigeria.     

Successful restoration of water level and surface area restored migrant bird populations in a Hungarian wetland

Water level and water surface area fluctuations are important factors determining abundance of bird populations and bird assemblages structure in a wetland habitat. The water level and water surface area of the Marsh T?m?rd (West Hungary) changed drastically between 1998 and 2008, and the marsh dried out because of scarce rainfall in 2000 and 2001. A habitat restoration in winter 2001 repaired the waterholding capacity of the marsh. We analyzed changes in parameters of bird assemblages in investigated wetland area in relation of environmental factors. We used full redundancy analysis (RDA) on number of caugth migratory birds per year, species richness, diversity and evenness of bird assemblages to examine correlations among water level, water surface area and vegetation core. Species like water rail, common snipe, river warbler, Savi’s warbler, great reed warbler, reed warbler, marsh warbler, sedge warbler, reed bunting showed high and positive linear correlations with the water level and water surface area in the postbreeding period. Some wetland species, sedge warbler, Savi’s warbler and reed bunting as well as total number of caugth birds per year and total numbers of caugth species per year were clearly associated with thick marsh vegetation. According to our results the bird species composition of the wetland might have returned to the prerestoration levels and surface areas.     

Sackville Waterfowl Park,Sackville, New Brunswick,Canada. Baseline characterization,towards long-term monitoring

The Sackville Waterfowl Park, contains a 19 hectare shallow freshwater wetland created by reflooding a saltwater marsh that was drained three centuries ago. Its primary purpose is to provide wetland habitat and wildlife viewing opportunities to tourists and residents. This newly created, eutrophic wetland supports high densities of waterfowl, 2.1 and 3.3 brood ha^–1 in 1991 and 1992 respectively. It is hoped that long term monitoring of the Park's waterfowl population and wetland habitat will contribute to a better understanding of factors controlling breeding waterfowl populations.     

Implications of Climate Change for Bird Conservation in the Southwestern U.S. under Three Alternative Futures

Future expected changes in climate and human activity threaten many riparian habitats, particularly in the southwestern U.S. Using Maximum Entropy (MaxEnt3.3.3) modeling, we characterized habitat relationships and generated spatial predictions of habitat suitability for the Lucy’s warbler (Oreothlypis luciae), the Southwestern willow flycatcher (Empidonax traillii extimus) and the Western yellow-billed cuckoo (Coccyzus americanus). Our goal was to provide site- and species-specific information that can be used by managers to identify areas for habitat conservation and/or restoration along the Rio Grande in New Mexico. We created models of suitable habitat for each species based on collection and survey samples and climate, biophysical, and vegetation data. We projected habitat suitability under future climates by applying these models to conditions generated from three climate models for 2030, 2060 and 2090. By comparing current and future distributions, we identified how habitats are likely to change as a result of changing climate and the consequences of those changes for these bird species. We also examined whether land ownership of high value sites shifts under changing climate conditions. Habitat suitability models performed well. Biophysical characteristics were more important that climate conditions for predicting habitat suitability with distance to water being the single most important predictor. Climate, though less important, was still influential and led to declines of suitable habitat of more than 60% by 2090. For all species, suitable habitat tended to shrink over time within the study area leaving a few core areas of high importance. Overall, climate changes will increase habitat fragmentation and reduce breeding habitat patch size. The best strategy for conserving bird species within the Rio Grande will include measures to maintain and restore critical habitat refugia. This study provides an example of a presence-only habitat model that can be used to inform the management of species at intermediate scales.     

Community Structure of Wetland Birds During Spring Migration Through the Rainwater Basin

Abstract: Staging areas and migratory stopovers of wetland birds have the potential to function as geographic bottlenecks; entire populations within a flyway may be affected by the quality and quantity of available wetland habitat at stopover sites. Although approximately 90% of playa wetlands in the Rainwater Basin (RWB) region of south-central Nebraska, USA, have been destroyed, the area still provides essential stopover habitat for >10 million waterfowl each spring. We evaluated community patterns and species associations to assess importance of assembly rules in structuring wetland bird communities during migration and to better facilitate multispecies conservation and management strategies. We surveyed 36–40 playas twice weekly in the RWB and observed approximately 2.6 million individual migratory wetland birds representing 72 species during 3 spring migrations 2002–2004. We evaluated spatial and temporal species co-occurrence patterns of geese, dabbling ducks, diving ducks, and shorebirds using null model analysis. Goose species co-occurrence scores did not differ from random in any year of the study, suggesting that goose species frequently use the same habitats during migration. Co-occurrence patterns among dabbling ducks were not different than expected by chance in any year; however, when we evaluated co-occurrence at a weekly scale, dabbling ducks co-occurred less often than expected during weeks of peak migration (high abundance), indicating that dabbling duck species spatially segregated at high densities. Diving duck co-occurrence patterns did not differ from random in any year, suggesting that diving duck species used the same habitats during migration. Shorebird species co-occurred less often than expected in 2002 and 2004, and during weeks of high shorebird abundance, indicating that shorebird communities were distinctly structured during those times. Most association values among lesser snow geese (Chen caerulescens) and dabbling duck species were positive, indicating dabbling ducks did not avoid wetlands with snow geese, a concern for waterfowl managers. However, we frequently observed snow geese and dabbling ducks using different microhabitats within a wetland, which indicate species associations and co-occurrence patterns may have occurred at a finer spatial scale than we measured. This approach of co-occurrence analysis will allow wildlife managers charged with multispecies management at migration stopover sites to make informed conservation and management decisions based on community structure rather than historic single-species approaches.     

Habitat quality and drought effects on breeding mallard and other waterfowl populations in California,USA

As many as 500,000 waterfowl reside in California, USA, during summer, but little is known about the availability or quality of their habitats. Wetland size and distribution serve as proximate cues for habitat selection by breeding waterfowl in other parts of North America such as the Prairie Pothole Region. In heavily modified landscapes such as California's Central Valley, disturbance from factors like crop cultivation and urban development may limit access, affect survival, and decrease reproductive success. Water limitations due to recurring seasonal droughts pose another potential threat to breeding waterfowl. Spatial and temporal disparities in environmental resources may provide clearer indications of ultimate habitat selection. We addressed waterfowl habitat selection in 9 regions surveyed annually by California's Department of Fish and Wildlife to determine relative importance of drought severity, wetland area, and habitat quality on mallard (Anas platyrhynchos) and other waterfowl population dynamics from 2007–2019. High-quality habitat supports long-term population persistence of waterfowl. This study period included an extended drought (2012–2015) and flooding (2016–2017). Statewide, habitat quality was the best predictor of mallard and other waterfowl population fluctuations. The model that included intermediate habitat quality, which accounted for influence of adjacent land-use, outperformed models that included wetland area alone. At the regional level, drought severity out-ranked other variables in most regions, suggesting management at regional scales must account for climate. Drought accounted for bird declines in some regions and possible increases in others. This information could be used to identify areas for conservation priority based on projected drought frequency and severity.     

Bird species richness is associated with phylogenetic relatedness,plant species richness,and altitudinal range in Inner Mongolia

Bird species richness is mediated by local, regional, and historical factors, for example, competition, environmental heterogeneity, contemporary, and historical climate. Here, we related bird species richness with phylogenetic relatedness of bird assemblages, plant species richness, topography, contemporary climate, and glacial‐interglacial climate change to investigate the relative importance of these factors. This study was conducted in Inner Mongolia, an arid and semiarid region with diverse vegetation types and strong species richness gradients. The following associated variables were included as follows: phylogenetic relatedness of bird assemblages (Net Relatedness Index, NRI), plant species richness, altitudinal range, contemporary climate (mean annual temperature and precipitation, MAT and MAP), and contemporary‐Last Glacial Maximum (LGM) change in climate (change in MAT and change in MAP). Ordinary least squares linear, simultaneous autoregressive linear, and Random Forest models were used to assess the associations between these variables and bird species richness across this region. We found that bird species richness was correlated negatively with NRI and positively with plant species richness and altitudinal range, with no significant correlations with contemporary climate and glacial–interglacial climate change. The six best combinations of variables ranked by Random Forest models consistently included NRI, plant species richness, and contemporary‐LGM change in MAT. Our results suggest important roles of local ecological factors in shaping the distribution of bird species richness across this semiarid region. Our findings highlight the potential importance of these local ecological factors, for example, environmental heterogeneity, habitat filtering, and biotic interactions, in biodiversity maintenance.     

Mapping critical areas for migratory songbirds using a fusion of remote sensing and distributional modeling techniques

Of the 338 species identified as Nearctic-Neotropical migrants occurring in North America, 98.5% have been recorded in Texas. The seasonal migration of these birds is a well-studied natural phenomenon – individuals weighing < 15 g will cross in the Gulf of Mexico approximately 965 km non-stop, completing a total distance of 1900–3200 km over the course of 26–80 h. The physiologically demanding nature of this feat makes the Texas coastline crucial to the success of these species. We used a fusion of multi-spectral remote sensing data and distributional modeling techniques to generate and evaluate predictive maps identifying critical areas for migratory passerines on the Texas coast. Imagery acquired from Landsat 8 OLI, maps provided by United States Geological Survey and the Texas Department of Transportation, and migratory bird occurrence records from the eBird citizen-contributed database were used to build predictive distribution models using three algorithms. Using the AUC to compare model performance, the Random Forest produced the most accurate distribution model, followed by MaxEnt, and Support Vector Machine (0.98, 0.81, and 0.79, respectively). We interpreted, from Boosted Regression Tree analysis, that elevation is the single most influential factor in determining migrant occupancy, with vegetative biomass the least influential predictor. Our approach here allows conservation biologists a more sophisticated approach to identifying critical areas for migratory passerines across large spatial extents in a short amount of time.     

Habitat selection by postbreeding female diving ducks: influence of habitat attributes and conspecifics

Habitat selection studies of postbreeding waterfowl have rarely focused on within‐wetland attributes such as water depth, escape cover, and food availability. Flightless waterfowl must balance habitat selection between avoiding predation risks and feeding. Reproductively successful female ducks face the greatest challenges because they begin the definitive prebasic molt at or near the end of brood rearing, when their body condition is at a low point. We assessed the relative importance of habitat attributes and group effects in habitat selection by postbreeding female lesser scaup Aythya affinis on a 2332‐ha montane wetland complex during the peak flightless period (August) over seven years. Hypothesis‐based habitat attributes included percent open water, open water:emergent edge density, water depth, percent flooded bare substrate, fetch (distance wind can travel unobstructed), group size, and several interactions representing functional responses to interannual variation in water levels. Surveys of uniquely marked females were conducted within randomly ordered survey blocks. We fitted two‐part generalized linear mixed‐effects models to counts of marked females within survey blocks, which allowed us to relate habitat attributes to relative probability of occurrence and, given the presence of a marked female, abundance of marked individuals. Postbreeding female scaup selected areas with water depths > 40 cm, large open areas, and intermediate edge densities but showed no relation to flooded bare substrate, suggesting their habitat preferences were more influenced by avoiding predation risks and disturbances than in meeting foraging needs. Grouping behavior by postbreeding scaup suggests habitat selection is influenced in part by behavioral components and/or social information, conferring energetic and survival benefits (predation and disturbance risks) but potentially also contributing to competition for food resources. This study demonstrates the importance of incorporating group effects and interannual variability in habitat conditions when investigating habitat selection, particularly for seasons when waterfowl are aggregated.     

A bridge between oceans: overland migration of marine birds in a wind energy corridor

Located at the shortest overland route between the Gulf of Mexico and the Pacific Ocean, Mexico's Tehuantepec Isthmus is a globally important migratory corridor for many terrestrial bird species. The Pacific coast of the Isthmus also contains a significant wetland complex that supports large multi‐species aggregations of non‐breeding waterbirds during the boreal winter. In recent years, extensive wind energy development has occurred in the plains bordering these wetlands, directly along the migratory flyway. Using recent studies of movement patterns of three marine‐associated bird species – reddish egrets Egretta rufescens, brown pelicans Pelecanus occidentalis, and red knots Calidris canutus – from the northern Gulf of Mexico, we assess the use of the isthmus as a migratory corridor. Our data provide evidence that marine birds from the Gulf region regularly overwinter along the Pacific coast of Mexico and use the isthmus as a migratory corridor, creating the potential for interaction with terrestrial wind farms during non‐breeding. This study is the first to describe migration by marine‐associated bird species between the Gulf of Mexico and Pacific coast. These data contribute new information toward ongoing efforts to understand the complex migration patterns of mobile marine species, with the goal of informing integrated conservation efforts for species whose year‐round habitat needs cross ecoregional and geopolitical boundaries.     

Changes in avian species composition following surface mining and reclamation along a riparian forest corridor in southern Indiana

Data on the response of bird communities to surface mining and habitat modification are limited, with virtually no data examining the effects of mining on bird communities in and along riparian forest corridors. Bird community composition was examined using line transects from 1994 to 2000 at eight sites within and along a riparian forest corridor in southwestern Indiana that was impacted by an adjacent surface mining operation. Three habitats were sampled: closed canopy, riparian forest with no open water; fragmented canopy, riparian forest with flood plain oxbows; and reclaimed mined land with constructed ponds. Despite shifts in species composition, overall bird species richness, measured as the mean number of bird species recorded/transect route, did not differ among habitats and remained unchanged across years. More species were recorded solely on mined land than in either closed forest or forested oxbow habitats. Mined land provided stopover habitat for shorebirds and waterfowl not recorded in other habitats, and supported an assemblage of grassland-associated bird species weakly represented in the area prior to mining. A variety of wood warblers and other migrants were recorded in the forest corridor throughout the survey period, suggesting that, although surface mining reduced the width of the forest corridor, the corridor was still important habitat for movement of forest-dependent birds and non-resident bird species in migration. We suggest that surface mining and reclamation practices can be implemented near riparian forest and still provide for a diverse assemblage of bird species. These data indicate that even narrow (0.4 km wide) riparian corridors are potentially valuable in a landscape context as stopover habitats and routes of dispersal and movement of forest-dependent and migratory bird species.     

中国阿勒泰地区鸟类物种编目、丰富度格局和区系组成

中国阿勒泰地区位于新疆北部, 与哈萨克斯坦、俄罗斯、蒙古国交界, 该区包含阿尔泰山及山前荒漠和绿洲, 属于全球200个生物多样性最丰富和最具代表性生态区之一的阿尔泰-萨彦岭生物热点地区。阿勒泰地区生境多样, 鸟类物种资源丰富。尽管以往曾在阿勒泰地区进行过一些鸟类调查, 但对于该地区不同景观和生境类型中鸟类物种丰富度和分布尚无详尽报道。本文通过2013-2016年在中国境内阿尔泰山及山前平原地区对不同生境类型中的鸟类进行实地调查, 并总结文献资料及观鸟爱好者的记录数据, 重新整理了阿勒泰地区鸟类名录及地理分布, 分析了鸟类的物种组成、区系成分; 通过鸟类分布位点数据, 选取气候、土地覆被类型、人类足迹指数及地形共4类环境因子作为自变量建立MaxEnt生态位模型, 通过模拟77种鸟类的适宜分布区并叠加分布图层, 获得了阿勒泰地区的鸟类物种丰富度分布格局。结果表明: 阿勒泰共记录鸟类344种, 隶属19目55科149属, 其中雀形目163种。在垂直海拔带上, 鸟类物种数分别为高山裸岩带24种, 高山草甸带35种, 山地森林草原带172种, 低山灌木带130种, 荒漠草原带84种, 平原绿洲带173种, 以及各海拔带的湿地与水域生境中水鸟92种; 在区系成分上, 以北方型鸟类为主(170种, 占49.4%), 其次为广布种(93种, 占27.0%)。阿尔泰山地的鸟类区系呈现出西伯利亚动物区系特征, 山前平原地区呈现蒙新区分布特征, 因此, 阿勒泰地区动物地理区系属于古北界欧洲-西伯利亚亚界阿尔泰-萨彦岭区阿尔泰亚区; 山前平原地区属于古北界中亚亚界蒙新区西部荒漠亚区。MaxEnt模型推测阿勒泰地区山前平原绿洲地区、山地森林草原带和低山灌木带具有较高的鸟类物种丰富度, 尤其是额尔齐斯河流域下游的绿洲带宽阔, 鸟类物种丰富, 而高山区和荒漠生境中鸟类物种相对较少。模型预测的结果与实际调查情况相符。阿勒泰地区应采用生态友好的经济发展策略, 加强对乔木和灌木的保护, 这有助于维持较高的鸟类物种多样性。此外, 降低生境破碎化不仅对该地区物种保护有重要作用, 也对维持阿尔泰-萨彦岭生物热点地区的山地鸟类多样性有重要意义。     

千岛湖陆桥岛屿鸟类集团对栖息地片段化的敏感性及其季节变化

为探究千岛湖陆桥岛屿不同鸟类集团对栖息地片段化敏感性的差异和季节变化,于2009年4月—2012年1月鸟类繁殖季(4、5、6月)和冬季(11、12、1月)对千岛湖41个陆桥岛屿鸟类集团进行了研究。结果表明,冬季杂食鸟对片段化敏感性高于食虫鸟,繁殖季时二者无显著差异,繁殖季和冬季时下层鸟对片段化敏感性均高于林冠鸟,冬季留鸟对片段化敏感性高于候鸟,繁殖季则无显著差异。杂食鸟和留鸟对片段化敏感性存在季节差异,而食虫鸟、林冠鸟、下层鸟和候鸟对片段化敏感性均无季节差异。不同鸟类集团对栖息地片段化敏感性的差异和季节变化规律,有助于人们在栖息地管理和保护区设计时采取更有针对性的鸟类保护措施。     

长江口杭州湾鸻形目鸟类群落季节变化和生境选择

在长江口南岸杭州湾北岸滨海滩涂进行了鸻形目鸟类的资源调查,以及鸟类栖息地选择模式分析,2004年3月至2005年1月共统计到鸟类25种,春季优势种为大缤鹬(Calidris tenuirostris)、尖尾缤鹬(Calidris alpine)和红颈滨鹬(Calidris ruficollis);夏季为环颈(Charadrius alexandrinus)、青脚鹬(Tringa nebularia)和蒙古沙(Charadrius mongolus),秋季为环颈、红颈滨鹬和青脚鹬,冬季为黑腹滨鹬(Calidris alpina)、环颈和泽鹬(Tringa stagnatilis),鸟类总体数量呈春季>秋季>冬季>夏季,海堤外(自然滩涂)和堤内(人工湿地)鸟类种数四季大致相等,但鸟类平均密度季节差异显著。通过对样点内鸟类与环境因子进行多元分析,初步总结出堤外滩宽和光滩宽是影响鸟类栖息的最关键因子,海三棱草(Scirpus× mariquete)覆盖比例和潮上坪宽度的影响程度次之。堤内浅水塘比例和裸地比例是影响形目鸟类分布的关键因子,海三棱草覆盖比例也起正向作用。而人类干扰大、芦苇(Phragmites communis)/互花米草(Spartina alternifloral)密植和高水位的区域不利于鸟类利用。     

环境因子对东洞庭湖优势冬季水鸟分布的影响

东洞庭湖国家级自然保护区是我国乃至全球湿地水鸟的重要越冬栖息地,研究水鸟群落与环境因子之间的关系,对修复鸟类栖息地具有重要意义.2010和2011年冬季分别对东洞庭湖湿地冬季水鸟进行调查,采用典范对应分析(CCA)分析环境因子与优势水鸟分布的关系,采用偏CCA评估各环境因子的影响强度.结果表明： 到道路距离、到居民距离、斑块密度、植被类型数、水面面积和苔草面积对东洞庭湖冬季水鸟分布具有显著影响(P<0.05),其影响强度为苔草面积>斑块密度>到居民距离>植被类型数>水面面积>到道路距离,苔草面积和斑块密度对水鸟分布的影响达极显著水平(P<0.01),是影响东洞庭湖湿地冬季水鸟的主要环境因子;景观多样性和芦苇面积对水鸟分布的影响未达到显著水平(P>0.05).回归分析结果显示,环境因子对不同水鸟丰富度的影响不同,白琵鹭、罗纹鸭和黑腹滨鹬丰富度随苔草面积增大而减小,随斑块密度增大而增大;豆雁、白额雁、小白额雁和绿翅鸭丰富度随苔草面积增大而增大,随斑块密度增大而减小.东洞庭湖冬季水鸟分布是由以苔草面积、斑块密度为主的多环境因子综合作用的结果.