Habitat preferences of sympatric sandgrouse during the breeding season in Spain: a multi-scale approach

Predictive species’ distribution models may answer ecological questions about habitat selection, co-occurrence of species and competition between them. We studied the habitat preferences and segregation of two sympatric species of declining sandgrouse, the black-bellied sandgrouse (Pterocles orientalis) and the pin-tailed sandgrouse (Pterocles alchata), during the breeding season. We developed predictive models that related sandgrouse presence to environmental variables at three different spatial levels: large geographical, landscape and microhabitat scales. At the large geographical scale, differences between sandgrouse distributions, in the Iberian Peninsula, seem to be explained mainly in terms of bioclimatology: pin-tailed sandgrouse appear to be a more thermophilous species and occupy warmer sites usually located in flatter areas. At the landscape spatial level, in those areas that exhibit environmental conditions allowing for both species’ co-existence at a large geographical scale, black-bellied sandgrouse appear to be more tolerant to environmental variation than pin-tailed sandgrouse. At the microhabitat level, however, differences between species could be related to different flocking behaviour as a consequence of different sensitivities to vegetation structure and predators. Thus, the observed spatial distribution patterns are the result of different ecological factors that operate at different spatial levels. Conservation guidelines for these species should therefore consider their habitat preferences at large geographical, landscape and microhabitat scales.     

Contrasting habitat use of morphologically similar bat species with differing conservation status in south‐eastern Australia

The east‐coast free‐tailed bat Mormopterus norfolkensis Gray, 1839 is a threatened insectivorous bat that is poorly known and as such conservation management strategies are only broadly prescribed. Insectivorous bats that use human‐modified landscapes are often adapted to foraging in open microhabitats. However, few studies have explored whether open‐adapted bats select landscapes with more of these microhabitat features. We compared three morphologically similar and sympatric, molossid bats (genus Mormopterus) with different conservation status in terms of their association with vegetation, climate, landform and land‐use attributes at landscape and local habitat element scales. We predicted that these species would use similar landscape types, with semi‐cleared and low density urban landscapes used more than forested and heavily cleared landscapes. Additionally, we explored which environmental variables best explained the occurrence of each species by constructing post‐hoc models and habitat suitability maps. Contrary to predictions, we found that the three species varied in their habitat use with no one landscape type used more extensively than other types. Overall, M. norfolkensis was more likely to occur in low‐lying, non‐urban, riparian habitats with little vegetation cover. Mormopterus species 2 occupied similar habitats, but was more tolerant of urban landscapes. In contrast, Mormopterus species 4 occurred more often in cleared than forested landscapes, particularly dry landscapes with little vegetation cover. The extensive use of coastal floodplains by the threatened M. norfolkensis is significant because these habitats are under increasing pressure from human land‐uses and the predicted increase in urbanization is likely to further reduce the amount of suitable habitat.     

Sika deer distribution and habitat selection: the influence of the availability and distribution of food, cover, and threats

Large populations of sika deer occur in lowland heath, woodland, and grassland mosaics in southern England. Previous studies have focused on understanding single factors potentially affecting distribution and habitat selection of sika deer rather than considering simultaneously effects of landscape configuration and human disturbance on their distribution and habitat selection. This study measured effects of habitat availability, landscape structure, and human disturbance on where sika deer placed their home ranges and habitat selection within those ranges. Two main hypotheses were tested: (1) habitat selection differs according to landscape structure and habitat availability at both landscape and home range scales and (2) distribution of sources of human disturbance within the home range of deer affects their distribution. Results from radiotracking 31 females provided support for the first hypothesis and partial support for the second. Habitat selection at the landscape and home range scales differed between landscapes with different habitat structure and availability and was driven by distribution and availability of food and cover and a perceived risk linked to disturbance. Furthermore, deer selected open areas close to cover and this selection was stronger with presence of human disturbance, although results differed between study areas with different habitat distribution and level of disturbance. The study highlights the importance for managing deer of a balance between grazing and cover resources and the distribution of human disturbance.     

丹顶鹤多尺度生境选择机制——以黄河三角洲自然保护区为例

生境在鸟类生活史中发挥着重要的作用,关系到鸟类的生存和繁衍。由于鸟类对环境变化的响应发生在等级序列空间尺度上,基于多尺度的研究更能深入刻画鸟类-环境之间关系。以丹顶鹤(Grus japonensis)为研究对象,以其迁徙和越冬的重要地区-黄河三角洲自然保护区为研究区域,应用等级方差分解法和等级划分法,分析丹顶鹤与微生境、斑块、景观尺度因子之间的关系,探求丹顶鹤生境选择的主要影响因素和尺度。等级方差分解结果表明,在第1等级水平,景观尺度因子与微生境、斑块尺度因子之间的联合效应大于独立效应,景观尺度因子的独立效应大于微生境和斑块尺度因子;在第2等级水平,景观尺度上的景观组成因子重要性大于景观结构因子,微生境尺度上的植被和水分因子为重要影响因素。等级划分结果表明,景观尺度上,翅碱蓬滩涂、水体面积大小是主要影响因素;微生境尺度上,植被盖度和水深为主要限制因子;在斑块尺度上,斑块类型对丹顶鹤生境选择最为重要。研究认为,在黄河三角洲自然保护区,景观尺度是影响丹顶鹤生境选择的主要尺度,景观尺度因子通过与微生境和斑块尺度因子的独立和联合作用制约着丹顶鹤在保护区的生境选择和空间分布格局。建议加强对翅碱蓬滩涂、芦苇沼泽、水体等湿地生境的保护和管理,规范和控制保护区内人类活动强度。     

Habitat use for warren building by European rabbits (Oryctolagus cuniculus) in relation to landscape structure in a sand dune system

Several conservation efforts are being made to recover European rabbit populations (Oryctolagus cuniculus) on the Iberian Peninsula. Some of them focus on burrow management; others involve building different types of warren. A few studies have examined site selection for warren building, and these studies have considered only warren placement within sites and not the broader area surrounding these locations. The objective of this study was to evaluate how landscape pattern determines habitat selection by rabbits for warren building at different spatial scales. Landscape, home range scale, and microhabitat were the spatial scales used in this study. Warrens were not uniformly distributed over the study area but, rather were concentrated in areas with a high abundance and cover of Retama monosperma and high vegetation cover. Rabbits preferred digging warrens in areas with low fragmentation and where patches are few, large, and contiguous. Based on our results, we suggest that a study of landscape structure should be carried out before design habitat management, recovery or translocation programs. Such studies will need to take into account the physiognomy and size, shape, and continuity of patches in fragmented landscapes. Rabbit conservation programs must address areas that provide not only the maximum potential rate of intake, but also good soil and vegetation cover conditions for warren building and suitable surrounding areas.     

城市鸟类对斑块状园林栖息地的选择性

园林因在城市中呈斑块状分布而具有许多岛屿栖息地的特性,其内部结构和景观水平的结构同时也受到城市化的影响。对杭州市20个园林中鸟类物种的选择性分布进行了调查和分析,重点探讨了鸟类物种与园林面积、内部结构、微栖息地类型的分布、景观水平的结构、人为干扰等栖息地因素的关系。结果表明,杭州城市鸟类对园林栖息地具有较强的选择性,这不仅与园林的面积有关,还与园林的形状、植被盖度、微栖息地类型、连通性、隔离度、周围用地以及人为干扰等多种因素密切相关。园林栖息地间的异质性以及鸟类物种与栖息地结构的密切关系是园林鸟类选择性分布的主要原因。     

Multi-scale habitat models for reintroduced bird populations: a case study of South Island saddlebacks on Motuara Island

Understanding resource selection by animals is important when considering habitat suitability at proposed release sites within threatened species recovery programmes. Multi-scale investigatory approaches are increasingly encouraged, as the patchy distribution of suitable habitats in fragmented landscapes often determines species presence and survival. Habitat models applied to a threatened New Zealand forest passerine, the South Island saddleback (Philesturnus carunculatus carunculatus), reintroduced to Ulva Island (Stewart Island) found that at landscape scale breeding pairs? preferences for sites near the coast were driven by micro-scale vegetation structure. We tested these results by examining models of breeding site selection by a reintroduced saddleback population on Motuara Island (Marlborough Sounds) at two scales: (1) micro-scale, for habitat characteristics that may drive breeding site selection, and (2) landscape scale, for variations in micro-scale habitat characteristics that may influence site colonisation in breeding pairs. Results indicated that birds on Motuara Island responded similarly to those on Ulva Island, i.e. birds primarily settled at the margins of coastal scrub and forest and later cohorts moved into larger stands of coastal forest where they established breeding territories. Plant species composition was also important in providing breeding saddleback pairs with adequate food supply and nesting support. However, Motuara Island birds differed in their partitioning of habitat use: preferred habitats were used for nesting while birds were foraging outside territorial boundaries or in shared sites. These differences may be explained because Motuara has a more homogeneous distribution of microscale habitats throughout the landscape and a highly bird-populated environment. These results show that resource distribution and abundance across the landscape needs to be accounted for in the modelling of density?bird?habitat relationships. In the search for future release sites, food (invertebrates and fruiting tree species) should be abundant close to available nesting sites, or evenly spread and available throughout the landscape.     

Habitat use by endangered Japanese crayfish (<Emphasis Type="Italic">Cambaroides japonicus</Emphasis>) in low-gradient streams of southern Hokkaido,Japan: reach and microhabitat-scale analysis

The Japanese crayfish (Cambaroides japonicus), the only native crayfish in Japan, is endangered and has experienced rapid population declines. We surveyed the habitat requirements of Japanese crayfish at the reach and microhabitat scales in semi-natural low-gradient streams. Habitat use by Japanese crayfish differed between the spatial scales. Reach-scale analysis revealed that the bed slope was the only positive predictor of crayfish density. This finding indicates that relatively high-gradient reaches, such as headwater reaches, are an important habitat for the conservation of Japanese crayfish in low-gradient streams. Microhabitat-scale analysis showed that crayfish density was positively affected by substrate coarseness and the presence of instream vegetation cover (bank vegetation, woody debris, and leaf patches), whereas it was negatively affected by distance from the stream edge. Coarse substrates and vegetation cover may function as shelters from water flows and predators during low flow periods. The use of stream-edge areas may allow quick access to refugia and enable the crayfish to avoid unexpected flood disturbance and predation. These habitat characteristics should therefore be preserved for the conservation of Japanese crayfish, and scale-dependent habitat characteristics should be considered in future conservation plans.     

Humans alter habitat selection of birds on ocean‐exposed sandy beaches

Aim Resource‐selection functions (RSFs) can quantify and predict the density of animal populations across heterogeneous landscapes and are important conservation tools in areas subject to human disturbance. Sandy beach ecosystems have comparatively low habitat heterogeneity and structural relief in the intertidal zone, but intense human use. We aimed to develop predictive RSFs for birds on ocean‐exposed sandy beaches at two spatial scales, 25 ha (local scale) and 250 ha (landscape scale), and to test whether habitat selection of birds that commonly use the surf–beach–dune interface is influenced by the rates of human activities. Location Moreton and North Stradbroke Island, eastern Australia. Methods Avifauna and human activities were mapped on three sandy beaches covering 79 km of coastline for 15 months. Habitat characteristics of the surf–beach–dune interface were derived from remote sensing and ground surveys. RSFs were developed for 12 species of birds at two spatial scales: 25 ha (local scale) and 250 ha (landscape scale). Results  At local (25 ha) and landscape scales (250 ha), dune dimensions and the extent and type of vegetation structure were important predictors of bird density. Adding the frequency of human activities improved the predictive power of RSFs, suggesting that habitat selection of birds on beaches is modified by human use of these environments. Human activities occurred mostly in the mid‐ to lower intertidal zone of the beach, overlapping closely with the preferred habitats of Silver Gulls (Larus novaehollandiae), Pied Oystercatchers (Haematopus longirostris), Red‐capped Plovers (Charadrius ruficapillus) and endangered Little Terns (Sternula albifrons). Main conclusions In addition to demonstrating the appropriateness of RSFs to the surf–beach–dune interface, our results stress the need for systematic conservation planning for these ecosystems, where ecological values have traditionally been subsidiary to the maintenance of sand budgets and erosion control.     

The nest predator community of grassland birds responds to agroecosystem habitat at multiple scales

Nest predation is the leading cause of reproductive failure for grassland birds of conservation concern. Understanding variation in nest predation rates is complicated by the diverse assemblage of species known to prey on nests. As part of a long‐term study of grassland bird ecology, we monitored populations of predators known to prey on grassland bird nests. We used information theoretic approach to examine the predator community's association with habitat at multiple scales, including local vegetation structure of grassland patches, spatial attributes of grassland patches (size and shape), and landscape composition surrounding grassland patches (land cover within 400 and 1600 m). Our results confirmed that nest predators respond to habitat at multiple scales and different predator species respond to habitat in different ways. The most informative habitat models we selected included variability in local vegetation (CV in the density of forbs), local patch (area and edge‐to‐interior ratio), and landscape within a 1600 m buffer around grasslands (percent of land covered by human structures and development). As a separate question, we asked if models that incorporated information from multiple scales simultaneously might improve the ability to explain variation in the predator community. Multi‐ scale models were not consistently superior to models derived from variables focused at a single spatial scale. Our results suggest that minimizing human development on and surrounding conservation land and the management of the vegetation structure on grassland fragments both may benefit grassland birds by decreasing the risk of nest predation.     

Urbanisation at Multiple Scales Is Associated with Larger Size and Higher Fecundity of an Orb-Weaving Spider

Urbanisation modifies landscapes at multiple scales, impacting the local climate and changing the extent and quality of natural habitats. These habitat modifications significantly alter species distributions and can result in increased abundance of select species which are able to exploit novel ecosystems. We examined the effect of urbanisation at local and landscape scales on the body size, lipid reserves and ovary weight of Nephila plumipes, an orb weaving spider commonly found in both urban and natural landscapes. Habitat variables at landscape, local and microhabitat scales were integrated to create a series of indexes that quantified the degree of urbanisation at each site. Spider size was negatively associated with vegetation cover at a landscape scale, and positively associated with hard surfaces and anthropogenic disturbance on a local and microhabitat scale. Ovary weight increased in higher socioeconomic areas and was positively associated with hard surfaces and leaf litter at a local scale. The larger size and increased reproductive capacity of N.plumipes in urban areas show that some species benefit from the habitat changes associated with urbanisation. Our results also highlight the importance of incorporating environmental variables from multiple scales when quantifying species responses to landscape modification.     

Microhabitat Characteristics of Preble's Meadow Jumping Mouse High-Use Areas

ABSTRACT Riparian wetlands are complex ecosystems containing species diversity that may easily be affected by anthropogenic disturbances. Preble's meadow jumping mouse (Zapus hudsonius preblei) is a federally threatened subspecies dependent upon riparian wetlands along the Front Range of Colorado and southeastern Wyoming, USA. Although habitat improvements for Preble's meadow jumping mouse are designed at multiple spatial scales, most knowledge about its habitat requirements has been described at a landscape scale. Our objective was to improve our understanding of Preble's meadow jumping mouse microhabitat characteristics within high-use areas (hotspots), which are essential for the development of effective management and conservation strategies. We evaluated Preble's meadow jumping mouse habitat by describing areas of high use and no use as determined from monitoring radiocollared individuals. A comparison of microhabitat characteristics from random samples of high-use and no-use areas indicated that mice use areas closer to the center of the creek bed and positively associated with shrub, grass, and woody debris cover. Distance to center of the creek bed, and percent of shrub and grass cover also had the greatest relative importance of habitat variables modeled when describing high-use areas. High-use areas contained 3 times more grass cover than forb cover, and overall had a greater proportion of wetland shrub and grass cover. However, proportion of cover type (shrub or grass) did not vary greatly between high-use and no-use areas. Our results suggest that management and conservation efforts should continue to focus on establishment of native wetland vegetation near streams and creeks. For example, vegetation should include shrubs such as willow (Salix spp.), narrowleaf cottonwood (Populus angustifolia), alder (Alnus incana), grasses such as fescue (Fescue spp.), sedges (Carex spp.), and rush (Juncus spp).     

Sexual differences in microhabitat selection of breeding little bustards Tetrax tetrax: Ecological segregation based on vegetation structure

We examined sexual differences in patterns of vegetation structure selection in the sexually dimorphic little bustard. Differences in vegetation structure between male, female and non-used locations during reproduction were examined and used to build a presence/absence model for each sex. Ten variables were measured in each location, extracting two PCA factors (PC1: a visibility-shelter gradient; PC2: a gradient in food availability) used as response variables in GLM explanatory models. Both factors significantly differed between female, male and control locations. Neither study site nor phenology was significant. Logistic regression was used to model male and female presence/absence. Female presence was positively associated to cover of ground by vegetation litter, as well as overall vegetation cover, and negatively to vegetation density over 30 cm above ground. Male presence was positively related to litter cover and short vegetation and negatively to vegetation density over 30 cm above ground. Models showed good global performance and robustness. Female microhabitat selection and distribution seems to be related to the balance between shelter and visibility for surveillance. Male microhabitat selection would be related mainly to the need of conspicuousness for courtship. Accessibility to food resources seems to be equally important for both sexes. Differences suggest ecological sexual segregation resulting from different ecological constraints. These are the first detailed results on vegetation structure selection in both male and female little bustards, and are useful in designing management measures addressing vegetation structure irrespective of landscape composition. Similar microhabitat approaches can be applied to manage the habitat of many declining farmland birds.     

Multi-Scale Foraging Habitat Use and Interactions by Sympatric Cervids in Northeastern China

Abstract: Moose (Alces alces) and roe deer (Capreolus pygargus) are sympatric in the forest region of northeastern China. Using univariate analyses of feeding sign data, we found the 2 species were positively associated, but there were distinctions between their use of forage resources across landscape, patch, and microhabitat scales. We used resource selection function models to predict the influence of environmental covariates on moose and roe deer foraging; we detected covariate effects at the landscape and microhabitat scales but not at the patch scale. Forage resources used by the 2 species were similar, but moose used wetter areas and more low-visibility habitats than did roe deer, which strongly avoided areas with sparse vegetation. Both species were influenced by forage abundance and distribution at the microhabitat scale but exhibited differences in intensity of use of plant species and microhabitats. Moose used areas with deeper snow and avoided hiding cover; roe deer avoided areas with higher total basal areas of tree stems and preferred areas with high plant species richness. For moose, there was a trade-off in the use of concealment cover between the landscape and microhabitat scales. We detected avoidance by moose of roads where roe deer occurred. Roe deer exhibited more capacity for coping with human disturbance and interspecific interaction. In areas similar to our study area, road closures and suppression of roe deer near roads within 3–5 years postlogging may benefit moose. Furthermore, a mosaic of areas with different logging intervals may contribute to spatial separation of moose and roe deer and promote their coexistence.     

Vegetation maps based on remote sensing are informative predictors of habitat selection of grassland birds across a wetness gradient

Vegetation is a major environmental factor influencing habitat selection in bird species. High resolution mapping of vegetation cover is essential to model the distribution of populations and improve the management of breeding habitats. However, the task is challenging for grassland birds because microhabitat variations relevant at the territory scale cannot be measured continuously over large areas to delineate areas of higher suitability. Remote sensing may help to circumvent this problem. We addressed this issue by using SPOT 5 imagery and phytosociological data. We mapped grassland vegetation in a floodplain using two methods. We (i) mapped the continuous Ellenberg index of moisture and (ii) identified 5 vegetation classes distributed across the wetness gradient. These two methods produced consistent output maps, but they also provided complementary results. Ellenberg index is a valuable proxy for soil moisture while the class approach provided more information about vegetation structure, and possibly trophic resources. In spite of the apparent uniformity of meadows, our data show that birds do not settle randomly along the moisture and vegetation gradients. Overall birds tend to avoid the driest vegetation classes, i.e. the highest grounds. Thus, vegetation maps based on remote sensing could be valuable tools to study habitat selection and niche partition in grassland bird communities. It is also a valuable tool for conservation and habitat management.     

震旦鸦雀在镶嵌型芦苇收割生境中的巢址选择

大规模的芦苇收割会对在该生境中繁殖的鸟类产生严重影响。为降低芦苇收割对鸟类繁殖的负面影响,许多地区的湿地管理者逐渐采用了镶嵌型的芦苇收割方式。但是,这种新的芦苇管理方式对鸟类繁殖期生境选择的作用机理尚不清楚。震旦鸦雀是一种主要分布在我国东部、完全依赖芦苇生境而生存的珍稀鸟类,已被IUCN定为全球性近危物种。大规模的芦苇收割导致其适宜生境丧失,被认为是该物种面临的一个主要威胁。选择山东黄河三角洲国家级自然保护区为研究地区,采用AIC信息准则法,从巢址微生境、巢域斑块和全模型3个水平上对可能影响震旦鸦雀巢址选择的生境因子进行了逻辑斯蒂回归分析,并重点探讨芦苇镶嵌收割对其巢址选择的影响以及不同水平的相互效应。结果发现,震旦鸦雀的巢址选择受巢址微生境和巢域斑块尺度双重水平的影响,但巢址微生境因子的影响要大于巢域斑块因子。在巢址微生境水平上,影响震旦鸦雀巢址选择的因素有:1.5—2.5 m旧芦苇的密度、2.5 m以上新芦苇的密度、香蒲密度和巢的可见度;在巢域斑块水平上,影响因素包括芦苇生境类型、旧芦苇斑块面积的比例和植被盖度;在综合模型中,影响因素有1.5—2.5 m旧芦苇的密度、2.5 m以上新芦苇的密度、香蒲密度、巢的可见度和植被盖度。综上,震旦鸦雀倾向于在植被盖度较高、具有一定比例(18.3%)旧芦苇面积、1.5—2.5 m旧芦苇密度较高、可见度较低的生境斑块中筑巢。研究中,78.7%(n=141)的震旦鸦雀将巢筑在新旧芦苇混合的微生境中,其中36.9%的巢址附近旧芦苇的比例在一半以上;53.2%(n=111)的巢筑于新、旧两种芦苇茎秆之上,22.3%的巢的支撑芦苇中旧芦苇所占比例在一半以上。研究结果表明,旧芦苇在震旦鸦雀巢址选择和筑巢过程中发挥了重要作用。由于大范围的芦苇收割在微生境水平上可降低1.5—2.5 m旧芦苇的密度,在巢域斑块尺度上可降低旧芦苇斑块面积的比例,因此建议,在震旦鸦雀的繁殖地,未来的芦苇收割应采用镶嵌收割的形式,并至少应保留面积在20%以上的结构较好的旧芦苇斑块,以供震旦鸦雀选择巢址和繁衍后代。     

Sage-Grouse Habitat Selection During Winter in Alberta

ABSTRACT Greater sage-grouse (Centrocercus urophasianus) are dependent on sagebrush (Artemisia spp.) for food and shelter during winter, yet few studies have assessed winter habitat selection, particularly at scales applicable to conservation planning. Small changes to availability of winter habitats have caused drastic reductions in some sage-grouse populations. We modeled winter habitat selection by sage-grouse in Alberta, Canada, by using a resource selection function. Our purpose was to 1) generate a robust winter habitat-selection model for Alberta sage-grouse; 2) spatially depict habitat suitability in a Geographic Information System to identify areas with a high probability of selection and thus, conservation importance; and 3) assess the relative influence of human development, including oil and gas wells, in landscape models of winter habitat selection. Terrain and vegetation characteristics, sagebrush cover, anthropogenic landscape features, and energy development were important in top Akaike's Information Criterion-selected models. During winter, sage-grouse selected dense sagebrush cover and homogenous less rugged areas, and avoided energy development and 2-track truck trails. Sage-grouse avoidance of energy development highlights the need for comprehensive management strategies that maintain suitable habitats across all seasons.     

Habitat selection of breeding riparian birds in an urban environment: untangling the relative importance of biophysical elements and spatial scale

Aim Urbanization is a leading threat to global biodiversity, yet little is known about how the spatial arrangement and composition of biophysical elements – buildings and vegetation – within a metropolitan area influence habitat selection. Here, we ask: what is the relative importance of the structure and composition of these elements on bird species across multiple spatial scales? Location The temperate metropolitan area of Cincinnati, Ohio, USA. Methods We surveyed breeding birds on 71 plots along an urban gradient. We modelled relative density for 48 bird species in relation to local woody vegetation composition and structure and to tree cover, grass cover and building density within 50–1000 m of each plot. We used an information‐theoretic approach to compare models and variables. Results At the proximate scale, native tree and understory stem frequency were the most important vegetation variables explaining bird distributions. Species’ responses to landscape biophysical features and spatial scales varied. Most native species responded positively to vegetation measures and negatively to building density. Models combining both local vegetation and landscape information represented best or competitive models for the majority of species, while models containing only local vegetation characteristics were rarely competitive. Smaller spatial scales (≤ 500 m) were most important for 36 species, and eight species had best models at larger scales (> 500 m); however, several species had competitive models across multiple scales. Main conclusions Habitat selection by birds within the urban matrix is the result of a combination of factors operating at both proximate and broader spatial scales. Efforts to manage and design urban areas to benefit native birds require both fine‐scale (e.g., individual landowners and landscape design) and larger landscape actions (e.g., regional comprehensive planning).     

四川卧龙国家级自然保护区多空间尺度下绿尾虹雉的生境选择

动物的生境选择具有空间尺度依赖性, 在不同空间尺度上影响生境选择的环境因素有所不同。研究不同空间尺度下动物生境选择的关键影响因子及其季节性变化, 对于全面了解物种的生境资源需求和开展生境保护具有重要意义。绿尾虹雉(Lophophorus lhuysii)是中国特有的高山雉类, 国家一级重点保护野生动物, 具有极高的保护价值。然而, 目前尚未对其不同尺度和时期的生境选择进行过探究。本研究于2019年10月至2020年10月, 在四川卧龙国家级自然保护区的羊角湾、魏家沟和文扎都3个区域共布设15条样线、303个样方, 并结合红外相机监测(176个红外相机位点), 对保护区内绿尾虹雉种群的生境利用状况进行了调查, 使用主成分分析和逻辑斯蒂回归模型分别从景观和微生境两个尺度对繁殖期(3‒8月)和非繁殖期(9月至翌年2月)的生境选择模式进行了分析。结果显示, 在景观尺度上, 在繁殖期和非繁殖期都显著偏好海拔较高(3,700‒ 4,300 m)、坡度较小(27°‒33°)、靠近阳坡、草甸和流石滩比例较高而森林和灌丛比例较低的生境。在微生境尺度上, 绿尾虹雉在繁殖期显著偏好岩石盖度较高的生境; 而非繁殖期则显著偏好草本盖度较高、灌木盖度和落叶盖度较低的生境。研究表明, 绿尾虹雉在景观和微生境尺度上均对生境有明显的选择性, 并且其微生境选择还存在季节性变化, 反映了该物种在生活史不同阶段具有不同的资源需求。本研究丰富了绿尾虹雉的基础生态学信息, 为卧龙及其他自然保护区绿尾虹雉的生境管理和种群保护工作提供了参考。     

Community composition of butterflies and bumblebees in fallows: niche breadth and dispersal capacity modify responses to fallow type and landscape

Fallows (i.e. fields temporarily taken out of production) provide important habitat for flower-visiting insects in intensively cultivated agricultural landscapes. Cost-efficiency of fallowing schemes could be enhanced through improved understanding of key characteristics of fallows and surrounding landscape that determine community composition and provide support for species of conservation concern. Impacts of fallow characteristics and landscape structure on the species composition of butterflies and bumblebees were studied in two types of perennial fallows in boreal farmland. To understand species’ responses to environmental factors from a conservation perspective, community composition was examined with respect to two species traits—niche breadth and dispersal capacity. Whereas overall species composition of butterflies and bumblebees was strongly affected by forest cover in the surrounding landscape, the studied species traits were most related to fallow type and the cover of perennial grasslands. Habitat breadth of butterflies was narrowest in long-term grassland fallows in landscapes with high grassland cover. Dispersal capacity of butterflies was also lowest in grassland-rich landscapes. Diet breadth of bumblebees was narrower in long-term grassland fallows than in short-term fallows. The results confirm that the diversity of butterflies and bumblebees can be enhanced by establishing and managing fallows both in open and forested landscapes. For conservation of habitat specialists and less mobile species, retention of long-term fallows in grassland-rich landscapes is apparently the best option. The results provide no justification for exempting forested regions or farms with high grassland cover from the ecological focus area requirement under the European Union’s current agricultural policy.