The Harvest and Management of Migratory Bird Eggs by Inuit in Nunatsiavut, Labrador

This paper presents the results of collaborative research conducted in 2007 on the harvest of migratory bird eggs by Inuit households of Nunatsiavut, Labrador. Harvest variability between communities and species is examined, as is the social and ecological factors affecting the 2007 Inuit egg harvest. Representing the first comprehensive account of Inuit egg use in Labrador, this information should be valuable to agencies responsible for managing migratory bird populations in North America and will contribute to a more informed understanding of the complexity and temporal variability in subsistence harvesting among Labrador Inuit. It is argued that the recognition of this complexity will be critical as the Nunatsiavut Government and other wildlife management agencies formulate management policies that are supportive rather, than constraining, to Inuit resource use in the future.     

Streamside Management Zones Compromised by Stream Crossings,Legacy Gullies,and Over‐Harvest in the Piedmont

Streamside management zone (SMZ) breakthroughs were identified and characterized to determine frequency and potential causes, in order to provide enhanced guidance for future water quality protection. Ten kilometers of SMZs were carefully examined for partial or complete breakthroughs. With partial breakthroughs the SMZ trapped sediment before it reached the stream, while complete breakthroughs appeared to have allowed sediment to have passed through with minimal restriction. A total of 41 breakthroughs occurred (33 complete, 8 partial) across 16 sites, averaging 1 complete breakthrough per 0.3 km of SMZ length. The most common complete breakthroughs were caused by stream crossings (42%), reactivation of legacy agricultural gullies (27%), and harvest related soil disturbances near/within SMZs (24%). Pearson correlations of site characteristics at breakthroughs indicated no strong relationships between breakthrough sites, representing the variable nature of these unique circumstances. Stream crossings are an intentional breakthrough for access purposes, but resulting environmental impacts can be reduced with best management practice implementation. Current recommendations for SMZs tend to work in most situations, yet further research is needed to identify causal factors and quantify breakthrough severity.     

Bird Use of Restoration and Reference Marshes Within the Barn Island Wildlife Management Area, Stonington, Connecticut, USA

/ Tidal marshes have been actively restored in Connecticut for nearly 20 years, but evaluations of these projects are typically based solely on observations of vegetation change. A formerly impounded valley marsh at the Barn Island Wildlife Management Area is a notable exception; previous research at this site has also included assessments of primary productivity, macroinvertebrates, and use by fishes. To determine the effects of marsh restoration on higher trophic levels, we monitored bird use at five sites within the Barn Island complex, including both restoration and reference marshes. Use by summer bird populations within fixed plots was monitored over two years at all sites. Our principal focus was Impoundment One, a previously impounded valley marsh reopened to full tidal exchange in 1982. This restoration site supported a greater abundance of wetland birds than our other sites, indicating that it is at least equivalent to reference marshes within the same system for this ecological function. Moreover, the species richness of birds and their frequency of occurrence at Impoundment One was greater than at 11 other estuarine marshes in southeastern Connecticut surveyed in a related investigation. A second marsh, under restoration for approximately ten years, appears to be developing in a similar fashion. These results complement previous studies on vegetation, macroinvertebrates, and fish use in this system to show that, over time, the reintroduction of tidal flooding can effectively restore important ecological functions to previously impounded tidal marshes.KEY WORDS: Estuarine; Tidal marsh; Wetland birds; Restoration     

陡坡地集流聚肥梯田技术的应用

本文根据径流农业和水土保持综合治理的基本原理,以及对辽西部陡坡地资源的调查研究,介绍了陡坡地集流聚肥梯田的内涵,集流,集流效果及其优化设计参数的确定。     

Development of a Bird Integrity Index: Measuring Avian Response to Disturbance in the Blue Mountains of Oregon, USA

The Bird Integrity Index (BII) presented here uses bird assemblage information to assess human impacts to 28 stream reaches in the Blue Mountains of eastern Oregon. Eighty-one candidate metrics were extracted from bird survey data for testing. The metrics represented aspects of bird taxonomic richness, tolerance or intolerance to human disturbance, dietary preferences, foraging techniques, and nesting strategies that were expected to be positively or negatively affected by human activities in the region. To evaluate the responsiveness of each metric, it was plotted against an index of reach and watershed disturbance that included attributes of land use/land cover, road density, riparian cover, mining impacts, and percent area in clearcut and partial-cut logging. Nine of the 81 candidate bird metrics remained after eliminating unresponsive and highly correlated metrics. Individual metric scores ranged from 0 to 10, and BII scores varied between 0 and 100. BII scores varied from 78.6 for a minimally disturbed, reference stream reach to 30.4 for the most highly disturbed stream reach. The BII responded clearly to varying riparian conditions and to the cumulative effects of disturbances, such as logging, grazing, and mining, which are common in the mountains of eastern Oregon. This BII for eastern Oregon was compared to an earlier BII developed for the agricultural and urban disturbance regime of the Willamette Valley in western Oregon. The BII presented here was sensitive enough to distinguish differences in condition among stream riparian zones with disturbances that were not as obvious or irreversible as those in the agricultural/urban conditions of western Oregon.     

Wintering Waterbirds and Recreationists in Natural Areas: A Sociological Approach to the Awareness of Bird Disturbance

Disturbance to wintering birds by human recreational activities has become a major concern for managers of many natural areas. Few studies have examined how recreationists perceive their effects on birds, although this impacts their behavior on natural areas. We surveyed 312 users on two coastal ornithological sites in Brittany, France, to investigate their perception of the effects of human activities on wintering birds. The results show that the awareness of environmental issues and knowledge of bird disturbance depends on the socioeconomic characteristics of each user group, both between the two sites and within each site. Results also indicate that, whatever the site and the user group, the vast majority of the respondents (77.6 %) believed that their own presence had no adverse effects on the local bird population. Various arguments were put forward to justify the users’ own harmlessness. Objective information on recreationists’ awareness of environmental issues, and particularly on their own impact on birds, is important to guide managers in their choice of the most appropriate visitor educational programs. We recommend developing global but also specific educational information for each type of user to raise awareness of their own impact on birds.     

Evaluating Links Between Forest Harvest and Stream Temperature Threshold Exceedances: The Value of Spatial and Temporal Data

We present the results of a replicated before‐after‐control‐impact study on 33 streams to test the effectiveness of riparian rules for private and State forests at meeting temperature criteria in streams in western Oregon. Many states have established regulatory temperature thresholds, referred to as numeric criteria, to protect cold‐water fishes such as salmon and trout. We examined across‐year and within‐year patterns of exceedance at control and treatment stream temperature probes. Determining whether an exceedance at the downstream end of a harvest was unambiguously related to harvest proved surprisingly difficult. The likelihood of a site exceeding its numeric criterion appeared related, in part, to the site's preharvest temperature range. Four control reaches as well as three preharvest treatment reaches exceeded their numeric criteria, necessitating additional analysis to evaluate timber harvest impacts. Nine percent of sites (3 of 33) both exceeded their numeric criteria and exhibited a potential harvest effect (16.7% of private sites [3 of 18], 0% of State sites [0 of 15]). After harvest, exceedances were typically observed in only the first of the two post‐harvest years. These findings highlight the importance of including temporal and spatial controls in temperature assessments of numeric criteria when the assessment's purpose is to determine whether exceedances are related to human activities.     

Comparative Influence of Forest Management and Habitat Structural Factors on the Abundances of Hollow-Nesting Bird Species in Subtropical Australian Eucalypt Forest

We examined the impact of single-tree selective logging and fuel reduction burns on the abundance of hollow-nesting bird species at a regional scale in southeastern Queensland, Australia. Data were collected on species abundance and habitat structure of dry sclerophyll production forest at 36 sites with known logging and fire histories. Sixteen bird species were recorded with most being resident, territorial, obligate hollow nesters that used hollows that were either small (<10 cm diameter) or very large (>18 cm diameter). Species densities were typically low, but combinations of two forest management and three habitat structural variables influenced the abundances of eight bird species in different and sometimes conflicting ways. The results suggest that habitat tree management for biodiversity in production forests cannot depend upon habitat structural characteristics alone. Management histories appear to have independent influence (on some bird species) that are distinguishable from their impacts on habitat structure per se. Rather than managing to maximize species abundances to maintain biodiversity, we may be better off managing to avoid extinctions of populations by identifying thresholds of acceptable fluctuations in populations of not only hollow-nesting birds but other forest dependent wildlife relative to scientifically valid forest management and habitat structural surrogates.