Regional Synthesis of Habitat Relationships in Shrubland Birds

Abstract: Shrubland birds are declining throughout the eastern United States. To manage scrub-shrub habitats for birds, managers need information on avian habitat relationships. Past studies have produced contradictory results in some cases and may be of limited generality because of site- and habitat-specific factors. We studied shrubland birds across 6 habitats in 3 New England states to provide more general information on habitat relationships than has been possible in past studies. Our study sites included all major scrub-shrub habitats in New England: wildlife openings, regenerating clear-cuts, beaver ponds, utility rights-of-way, pitch pine (Pinus rigida) woodlands, and scrub oak (Quercus ilicifolia) barrens and ranged from Connecticut to northern New Hampshire, with research conducted from 2002 to 2007. Using N-mixture models of repeated point counts, we found that 6 of 12 shrubland birds preferred areas with greater shrub cover. An additional 4 species appeared to prefer areas with lower-stature vegetation and greater forb cover. Eight of 10 bird species showed relationships with cover of individual plant species, with Spiraea spp., willows (Salix spp.), alders (Alnus spp.), and invasive exotics being the most important. We recommend that shrubland management for birds focus on providing 2 distinct habitats: 1) areas of tall (>1.5 m) vegetation with abundant shrub cover and 2) areas of lower (<1.5 m) vegetation with abundant forb cover but fewer shrubs.     

Postlogging Succession and Habitat Usage of Shrubland Birds

ABSTRACT In the first decades after logging, the vegetation structure of harvested areas changes rapidly due to succession. For shrubland birds, many of which specialize on regeneration of specific ages, the changing vegetation structure makes determining how much habitat is available for individual species difficult. We conducted a meta-analysis to determine how populations of shrubland birds in the eastern United States and Canada respond to succession in the first 20 years after timber harvest. Based on those results, we used the area under the abundance-time regression curves to estimate the proportion of regenerating forest actually used by each bird species. Of the 28 species for which we had sufficient data, 14 showed significant changes in abundance over time. For 6 species, abundance was highest immediately after logging and decreased thereafter. Abundances of 7 other species were initially low, peaked roughly 10 years after harvest, and declined thereafter. Based on these results, shrubland birds would be expected to occupy a mean of just 53% (SD = 17%) of regenerating forests up to 20 years old. Thus, current estimates of habitat availability for shrubland birds may be too high by a factor of 2. Our findings also suggest that managed openings should be maintained on longer rotations than are currently used, providing habitat for birds that prefer older regeneration.     

动物的生境选择

动物的生境选择颜忠诚陈永林（中国科学院动物研究所,北京１０００８０）ＨａｂｉｔａｔＳｅｌｅｃｔｉｏｎｉｎＡｎｉｍａｌｓ．ＹａｎＺｈｏｎｇｃｈｅｎｇ,ＣｈｅｎＹｏｎｇｌｉｎ（ＩｎｓｔｉｔｕｔｅｏｆＺｏｏｌｏｇｙ,ＡｃａｄｅｍｉａＳｉｎｉｃａ,Ｂｅｉｊｉ...     

四川山鹧鸪的分布及生境选择

研究了四川山鹧鸪(Arborophila rufipectus)的分布区域和栖息地的生境,认为四川山鹧鸪的分布范围比已知的要大,但其实际分布区呈明显的岛屿状,显示出生境的破碎化;指出四川山鹧鸪的适宜生境是原始的常绿阔叶林、针阔混交林和具有较大常绿落叶阔叶乔木树种盖度的多年生次生林,亦可选择部分人工林,而对地表灌丛密度大的次生幼林以及人工幼林生境不喜好。由于天然林的禁伐和生态林的管护,四川山鹧鸪的栖息地趋于稳定并有所扩大。但四川山鹧鸪仍然处于濒危状态。     

Parasites and Sexual Selection in Birds of Paradise

We studied blood parasite infections in relation to aspectsof sexual selection and mate choice in 10 species of birds ofparadise. Across species there was a significant, positive correlationbetween relative parasite intensity and showiness in males.Parasite infections also correlated across species with thedegree of sexual dimorphism and varied with mating systems.Promiscuous species were showier and had significantly higherparasite prevalences than monogamous species. Within one species,Lawes' Parotia (Parotia lawesii), parasite intensity was negativelycorrelated with all phenotypic traits examined, a pattern significantlydifferent than random. The mating success of males with lowparasite intensities varied, but males with high intensitiesdid not mate. Sampling of individual males on repeated occasionsrevealed large temporal differences in parasite counts whichspanned the range believed to affect behavior and mating success.Whereas the interspecific correlations support one predictionof the Hamilton and Zuk hypothesis on parasites and sexual selection,the intraspecific data are equivocal with respect to a secondprediction of this hypothesis. Parasites appear to influencethe behavior of Lawes' Parotia, but alternative explanationsto that of Hamilton and Zuk for this effect are equally plausibleand there is no evidence of a link between female choice andthe traits in males indicative of parasite loads. We suggestthat female Lawes' Parotia may be avoiding highly infected malesrather than actively choosing parasite-resistant males.     

Habitat Degradation and Conservation Status Assessment of Gallinaceous Birds in the Trans-Himalayas,China

Abstract: The greatest concentration of Chinese Galliformes occurs in the Trans-Himalayas. We selected 4 northwestern Yunnan counties (Lijiang, Shangri-la, Deqin, and Weixi) in the Trans-Himalayas to assess the conservation status of 9 gallinaceous forest birds. We developed maps depicting recent forest cover and modeled habitat availability of each gallinaceous forest bird based on 3 factors that restrict its distribution: geographic location, elevation range, and forest coverage. The conservation status of 4 species was inadequate, because <10% of their respective potential habitats were within existing nature reserves. To predict the historic habitats of the species we studied, we also delineated a forest map from the late 1950s. We calculated the loss and fragmentation of potential habitats within the past 40 years as degree of habitat degradation. Our results showed that all 9 species became reduced and fragmented of their potential habitats from the late 1950s to 2002. Assessing habitat degradation and conservation status of wild species could help identify the threatened species with poor protection and degraded habitats, thereby warranting more attention in future conservation strategies. To protect those threatened species, it is urgent that the government should design new nature reserves to fill the conservation gaps, and enlarge and strengthen the management of existing natural reserves to reduce effects of human activities on their habitats.     

鸭绿江河口湿地鸟类生境的破坏与修复

鸭绿江河口湿地国家级自然保护区共发现鸟类210种,目前只是在核心区才保留有少许的自然生境--黑嘴鸥(Larus saundersi)的巢址,生境破碎化、片段化现象严重.文章运用景观生态学、恢复生态学、保护生物学的原理和方法、兼顾保护与发展,遵循可持续发展的基本思想,进行生境修复,加强生态管理,使得鸭绿江河口湿地真正成为众多鸟类迁徙路上理想的歇脚地、加油站.     

大沙鼠对栖息地的选择

根据地形特点和植被状况在调查地共划分出５类生境,大沙鼠最适生境为白刺＋盐爪爪＋红柳半固定沙丘。另外,大沙鼠对栖息地的选择有明显的季节差异,在春季大沙鼠多栖息于白刺＋盐爪爪半固定沙丘;秋季,又向盐爪爪＋裸露土岗生境迁移。食物条件、地形特点和植被覆盖度是影响大沙鼠栖息地选择的三个重要因素。     

栖息地选择的理论与模型

栖息地选择理论和模型的发展经历了两个主要阶段:理想自由分布模型和空间直观的栖息地选择模型。随着对理论模型假设的放宽,近年来产生了越来越多的新模型。通过对栖息地选择过程的分析,提出了栖息地选择的几个关键环节:栖息地偏好、信息获取、行为决策及选择行为。在建立栖息地选择模型的各个关键环节上均存在大量有待解决的问题。目前对栖息地偏好的研究主要为相关分析,栖息地信息获取的过程仍然是一黑箱;对动物在栖息地选择过程中的行为决策以及对其生理状态的影响尚不了解,而解决这些问题需要生态学、生态学及认知学等多个领域的研究结果支持,也有待新的理论及方法加以充实,甚至还需要其他学科的介入。     

Role of Early Experience in Mixed-colony Odor Recognition in the Ants Manica rubida and Formica selysi

An experimental model of mixed societies of ants was used to test the effect of early conditioning to a mixed colony odor on interspecific recognition after various periods of separation, with Manica rubida (Myrmicinae) and Formica selysi (Formicinae). Recognition was evaluated by recording the behaviour of individuals interacting after they had been grouped in mixed societies. The observed frequency and nature of these interactions depended on the way the societies were made up (whether with the same or different species, and with or without previous exposure to that species). The recognition displayed by the workers was much more altered in interspecific than in intraspecific groupings, which is evidence of the existence of some species recognition. In addition, the adult is capable of recognizing the olfactory characteristics of its group, the group odor would be a mixture of individual odors.     

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.     

Roles of Birds and Bats in Early Tropical-Forest Restoration

Restoration of tropical forest depended in large part on seed dispersal by fruit-eating animals that transported seeds into planted forest patches. We tested effectiveness of dispersal agents as revealed by established recruits of tree and shrub species that bore seeds dispersed by birds, bats, or both. We documented restoration of dispersal processes over the first 76 months of experimental restoration in southern Mexico. Mixed-model repeated-measures randomized-block ANOVAs of seedlings recruited into experimental controls and mixed-species plantings from late-secondary and mature forest indicated that bats and birds played different roles in the first years of a restoration process. Bats dispersed pioneer tree and shrub species to slowly regenerating grassy areas, while birds mediated recruitment of later-successional species into planted stands of trees and to a lesser extent into controls. Of species of pioneer trees and shrubs established in plots, seven were primarily dispersed by birds, three by bats and four by both birds and bats. Of later-successional species recruited past the seedling stage, 13 were of species primarily dispersed by birds, and six were of species dispersed by both birds and bats. No later-successional species primarily dispersed by bats established in control or planted plots. Establishment of recruited seedlings was ten-fold higher under cover of planted trees than in grassy controls. Even pre-reproductive trees drew fruit-eating birds and the seeds that they carried from nearby forest, and provided conditions for establishment of shade-tolerant tree species. Overall, after 76 months of cattle exclusion, 94% of the recruited shrubs and trees in experimental plots were of species that we did not plant.     

Role of the Pineal in the Circadian System of Birds

Pinealectomy of sparrows abolishes the free running rhythm oflocomotor activity in constant darkness. Without their pineals,sparrows still entrain to light-dark cycles and show other signsthat they retain part, but not all, of the circadian system.Interruption of either the neural input to the pineal or itsneural output, or both, does not abolish the free running rhythm.Rhythmicity can be restored to a pinealectomized bird by implantingthe pineal of a donor into the anterior chamber of its eye.A model of the circadian system controlling locomotor behavioris proposed to account for these facts. We suggest that theavian pineal contains a self-sustained oscillator, and as aconsequence, produces a rhythmic hormonal output. Circadianfluctuations of this hormone entrain a damped oscillator locatedelsewhere, which in turn drives the locomotor activity. Eachoscillator has separate access to environmental light cycles.The behavior of a pinealectomized bird is determined exclusivelyby its damped oscillator. It does not free run because it lacksthe self-sustained oscillator which, however, can be restoredby transplantation. The transplanted pineal continues its self-sustainedcircadian hormonal output which entrains the damped oscillatorand restores the system to its normal state.     

Using Mountain Lion Habitat Selection in Management

Wildlife agencies are generally tasked with managing and conserving species at state and local levels simultaneously. Thus, it is necessary for wildlife agencies to understand basic ecological processes of a given species at multiple scales to aid decision making at commensurately varied spatial and behavioral scales. Mountain lions (Puma concolor) occur throughout California, USA, and are at the center of a variety of management and conservation issues. For example, they are genetically and demographically at risk in 1 region yet apparently stable and negatively affecting endangered species in another. Currently, no formal plan exists for mountain lions in California to deal with these diverse scenarios involving issues of local mountain lion population viability and problems related to predation of endangered species. To facilitate development of a state-wide management and conservation plan, we quantified habitat selection by mountain lions at 2 spatial scales across the range of environmental conditions in which the species is found in California. Our analyses used location data from individuals (n = 263) collared across the state from 2001–2019. At the home range scale, mountain lions selected habitat to prioritize meeting energetic demands. At the within home range scale, mountain lions avoided areas of human activity. Further, our analyses revealed 165,350–170,085 km², depending on season, of suitable mountain lion habitat in California. Fifty percent of the suitable habitat was on unprotected lands and thus vulnerable to development. These habitat selection models will help in the development of a state-wide conservation and management plan for mountain lions in California by guiding mountain lion population monitoring through time, prioritization of habitat to be conserved for maintaining demographic connectivity and gene flow, and efforts to mediate mountain lion-prey interactions. Our work and application area will help with wildlife policy and management decisions related to depredation problems at the local scale and issues of habitat connectivity at the statewide scale. © 2019 The Wildlife Society.     

Habitat Specialization by Birds in Western Amazonian White‐sand Forests

In the Peruvian Amazon, white‐sand forests are patchily distributed and restricted to a few localities in the North. Although recent studies have documented patterns of habitat specialization by plants in these unique forests, very few studies of the fauna of these habitats have been conducted. The species composition of the avifauna of the white‐sand forests at six localities in the region was sampled by conducting transects and point counts. Surrounding habitats were also sampled to compare avifaunal communities and to determine the degree of restriction of bird species to white‐sand habitats. Non‐metric multidimensional scaling analysis showed that bird communities of white‐sand forests were more similar to each other than they were to terra firme or flooded forest communities. Sites on either side of the Amazon‐Marañón barrier were the most similar within habitat type consistent with the hypothesis that these rivers represent a major biogeographic barrier. Twenty‐six species, belonging to 13 families, were to some degree specialized to white‐sand forests. This is the first comprehensive ornithological assessment carried out on these habitats in Peru. The high degree of habitat specialization found in these 26 bird species highlights the need for conservation and management measures that will protect white‐sand forests.     

An Anthropogenic Habitat Facilitates the Establishment of Non-Native Birds by Providing Underexploited Resources

Anthropogenic modification of habitats may reduce the resources available for native species, leading to population declines and extinction. These same habitats often have the highest richness of non-native species. This pattern may be explained if recently human-modified habitats provide novel resources that are more accessible to non-native species than native species. Using non-native birds in the Iberian Peninsula as a case study, we conduct a large-scale study to investigate whether non-native species are positively associated with human modified habitats, and to investigate whether this positive association may be driven by the presence of resources that are not fully exploited by native species. We do this by comparing the functional diversity and resource use of native and non-native bird communities in a recently human-modified habitat (rice fields) and in more traditional habitats in the Iberian Peninsula. The functional diversity of native bird communities was lower in rice fields, but non-native birds were positively associated with rice fields and plugged this gap. Differences in resource use between native and non-native species allowed non-native species to exploit resources that were plentiful in rice fields, supporting the role of underexploited resources in driving the positive association of non-native birds with rice fields. Our results provide a potential mechanism explaining the positive association of non-native species with anthropogenic habitats, and further work is needed to test if this applies more generally.     

Patterns of Endemism and Habitat Selection in Coalbed Microbial Communities

Microbially produced methane, a versatile, cleaner-burning alternative energy resource to fossil fuels, is sourced from a variety of natural and engineered ecosystems, including marine sediments, anaerobic digesters, shales, and coalbeds. There is a prevailing interest in developing environmental biotechnologies to enhance methane production. Here, we use small-subunit rRNA gene sequencing and metagenomics to better describe the interplay between coalbed methane (CBM) well conditions and microbial communities in the Alberta Basin. Our results show that CBM microbial community structures display patterns of endemism and habitat selection across the Alberta Basin, consistent with observations from other geographical locations. While some phylum-level taxonomic patterns were observed, relative abundances of specific taxonomic groups were localized to discrete wells, likely shaped by local environmental conditions, such as coal rank and depth-dependent physicochemical conditions. To better resolve functional potential within the CBM milieu, a metagenome from a deep volatile-bituminous coal sample was generated. This sample was dominated by Rhodobacteraceae genotypes, resolving a near-complete population genome bin related to Celeribacter sp. that encoded metabolic pathways for the degradation of a wide range of aromatic compounds and the production of methanogenic substrates via acidogenic fermentation. Genomic comparisons between the Celeribacter sp. population genome and related organisms isolated from different environments reflected habitat-specific selection pressures that included nitrogen availability and the ability to utilize diverse carbon substrates. Taken together, our observations reveal that both endemism and metabolic specialization should be considered in the development of biostimulation strategies for nonproductive wells or for those with declining productivity.     

莲花山斑尾榛鸡春季栖息地选择

20 0 3年 3～ 4月 ,在甘肃省莲花山自然保护区 ,利用无线电遥测和直接观察 ,分析了斑尾榛鸡(Bonasasewerzowi)的栖息地选择特征。结果表明 ,斑尾榛鸡春季栖息地一般在东北坡向 ,并具有高大乔木、下层植被盖度较高、灌丛较丰富的特点 ,这与食物丰富度较高及环境隐蔽性较强有关。栖息地质量对于配对活动的成功与否有一定影响。分析表明 ,栖息地内 0 5～ 2 5m植被水平遮挡度、柳树数量、箭竹数量是影响斑尾榛鸡春季栖息地选择的关键因子。建议在对斑尾榛鸡栖息地采取保护措施时 ,不仅要保护原生乔木 ,还要加强对灌丛生境的保护。