Landscape use by gulls (Larus spp.)

In contrast to the negative impacts of landscape change on many aspects of biodiversity, scavenging bird species, like gulls (Larus spp.), have reacted positively and expanded their ranges. This in tum has brought a number of problems, including; damage to town centres, an increased risk of disease transmission to humans, domestic animals and livestock, an increased risk of collision with aircraft and a threat to vulnerable seabird populations. A great deal of money has been invested in measures to mitigate these problems. However, these have often been hampered by a failure to understand the ecology of the system concerned. This study employs a variety of statistical techniques to investigate factors related to the spatial and temporal distribution of gulls, the possible problems they may cause and the efficacy of measures to reduce the impact of these problems. Using structural equation modelling (SEM) it was possible to show that in contrast to other groups, like corvids which use landfill sites close to their roosts throughout the year, gulls rely most heavily on landfill sites as a source of food during the winter. However, analysis of the spatial distribution of winter gull roosts using negative binomial generalised linear models (GLMs) showed that only roosts of the black-headed gull (Larus 'ridibundasv were positively influenced by proximity to landfill sites. In contrast to the winter, when roosts were widely distributed, during the summer roosts had a coastal distribution. The problems posed by gulls to air safety and human health were investigated by analysing the spatial patterns of accidents and the incidence of salmonella carriage by 3 wild birds. In the first, bivariate k-means clustering revealed that strikes on Royal Air Force (RAF) aircraft by gulls were clustered within the 6 km surrounding major (>1000 individuals) gull roosts and landfill sites. These results were used to identify additional areas capable of supporting large numbers of gulls, and hence likely to represent a threat to aircraft in the future. I used survival analysis to investigate temporal and spatial patterns in wild bird salmonella. Passerines were more likely to be infected with salmonella than non-passerines and further analysis was indicative of gulls having a higher rate of salmonella infection than other non-passerines. Salmonella prevalence in wild birds was greatest during the winter and spring, and in areas with large populations of cattle. Having investigated the factors determining where gulls were and the risks they posed to aircraft safety and human health, I analyse the efficacy of a range of management techniques to control problem gull populations, using linear mixed effects models (LMEs). This revealed that techniques with occasional lethal events were the most effective. By using a range of statistical techniques, it was possible to disentangle a series of complex and often interacting relationships between gulls, the landscape and humans.EThOS - Electronic Theses Online ServiceCentral Science Laboratory, Newcastle UniversityGBUnited Kingdo

Methods to quantify avian airspace use in relation to wind energy development

It is likely that there will continue to be a substantial increase in the number of wind turbines as we aim to meet global energy demands through renewable sources. However, these structures can have adverse impacts on airborne wildlife, such as posing a potential collision risk with the turbine structure. A range of methods and technologies have been applied to the collection of bird flight parameters, such as height and speed, to improve the estimation of potential collision compared with traditional visual methods, but these are currently not applied in a consistent and systematic way. To this end, a systematic literature search was conducted to (1) examine the methods and technologies that can be used to provide bird flight data to assess the impact of wind energy developments and (2) provide an updated framework to guide how they might be most usefully applied within the impact assessment process. Four empirical measurement methods were found that improve the estimation of bird flight parameters: radar, telemetry, ornithodolite and LiDAR. These empirical sensor-based tools were typically more often applied in academic peer-reviewed papers than in report-based environmental statements. Where sensor-based tools have been used in the report-based literature, their inconsistent application has resulted in an uncertain regulatory environment for practitioners. Our framework directly incorporates sensor-based methods, together with their limitations and data requirements, from pre-deployment of infrastructure to post-consent monitoring of impacts. This revised approach will help improve the accuracy of estimation of bird flight parameters for ornithological assessment of wind energy. Sensor-based tools may not be the most cost-effective. However, a precedent has been set for wind energy development consent refusal based on ornithological impact assessment, and therefore the cost of collecting accurate and reliable flight data may be balanced favourably against the cost of development consent refusalacceptedVersio

A review to inform the assessment of the risk of collision and displacement in petrels and shearwaters from offshore wind developments in Scotland

The report presents a review of the published literature to collate and synthesise the existing evidence base for the assessment of the impacts of offshore wind farms and associated activities on three focal species: Manx Shearwater, European Storm-petrel and Leach's Storm-petrel. It identifies critical gaps in existing knowledge, outlines the challenges to filling data gaps, and makes recommendations for possible approaches for improving the existing evidence base. The report includes particular reference to Scotland's Sectoral Marine Plan Options, the specific risks posed to nocturnally active petrels and shearwaters by artificial lighting, and how light attraction may influence assessment of other risks (e.g. collision). Potential mitigation methods are outlined

Behavioural responses of non-breeding waterbirds to marine traffic in the near-shore environment

Capsule: Recording of behavioural responses to ferry traffic for 11 target species showed that Red-throated Diver Gavia stellata, Slavonian Grebe Podiceps auratus, and Black-throated Diver Gavia arctica were most likely to react to passing vessels. Aim: To provide information on how responses to marine traffic vary between waterbird species to inform marine spatial planning and environmental impact assessments in the near-shore environment. Methods: We recorded behavioural responses to ferry traffic for 11 target species in near-shore waters: Common Eider Somateria mollissima, Goldeneye Bucephala clangula, Long-tailed Duck Clangula hyemalis, Velvet Scoter Melanitta fusca, Red-breasted Merganser Mergus serrator, Black-throated Diver, Great Northern Diver Gavia immer, Red-throated Diver, European Shag Gulosus aristotelis, Slavonian Grebe and Black Guillemot Cepphus grylle. Responses were analysed using generalized linear models and mixed models. Results: Red-throated Diver, Black-throated Diver and Slavonian Grebe were the most likely species to exhibit a response to passing vessels. While Red-throated Divers and Slavonian Grebes were highly likely to flush, Black-throated Divers and Great Northern Divers rarely took flight, instead favouring swim or dive responses. In rougher sea conditions birds were more likely to take flight, and the propensity to respond declined across the wintering period. Conclusions: This research provides comparative evidence on the behavioural responses of waterbirds to marine traffic. The results support previous studies which highlighted the high sensitivity of diver species to disturbance and provide new evidence that Slavonian Grebe may also be a high sensitivity species

A framework for studying the effects of offshore wind energy development on birds and bats in the Eastern United States

Offshore wind energy development (OWED), while a key strategy for reducing carbon emissions, has potential negative effects to wildlife that should be examined to inform decision making and adaptive management as the industry expands. We present a conceptual framework to guide the long-term study of potential effects to birds and bats from OWED. This framework includes a focus on exposure and vulnerability as key determinants of risk. For birds and bats that are exposed to OWED, there are three main effects of interest that may impact survival and productivity: 1) collision mortality, 2) behavioral responses, including avoidance, displacement, and attraction, and 3) habitat-mediated effects to prey populations. If these OWED effects cause changes in survival and/or breeding success (e.g., fitness), they have the potential for population-level consequences, including changes in population size and structure. Understanding the influence of ecological drivers on exposure and effect parameters can help to disentangle the potential impacts of OWED from other stressors. We use this theoretical framework to summarize existing relevant knowledge and identify current priority research questions (n=22) for the eastern United States, where large-scale development of OWED is primarily in the planning and early construction phase. We also identify recommendations for study design and further prioritization of research topics

Framework for assessing and mitigating the impacts of offshore wind energy development on marine birds

Offshore wind energy development (OWED) is rapidly expanding globally and has the potential to contribute significantly to renewable energy portfolios. However, development of infrastructure in the marine environment presents risks to wildlife. Marine birds in particular have life history traits that amplify population impacts from displacement and collision with offshore wind infrastructure. Here, we present a broadly applicable framework to assess and mitigate the impacts of OWED on marine birds. We outline existing techniques to quantify impact via monitoring and modeling (e.g., collision risk models, population viability analysis), and present a robust mitigation framework to avoid, minimize, or compensate for OWED impacts. Our framework addresses impacts within the context of multiple stressors across multiple wind energy developments. We also present technological and methodological approaches that can improve impact estimation and mitigation. We highlight compensatory mitigation as a tool that can be incorporated into regulatory frameworks to mitigate impacts that cannot be avoided or minimized via siting decisions or alterations to OWED infrastructure or operation. Our framework is intended as a globally-relevant approach for assessing and mitigating OWED impacts on marine birds that may be adapted to existing regulatory frameworks in regions with existing or planned OWED

Modelling flight heights of marine birds to more accurately assess collision risk with offshore wind turbines

1. The number of offshore wind farms is rapidly increasing as they are a critical part of many countries' renewable energy strategies. Quantifying the likely impacts of these developments on wildlife is a fundamental part of the impact assessments required in many regions before permission for developments is granted. A key concern related to wind turbines is the risk of birds colliding with turbine blades. We present a novel method to generate species-specific flight height distributions which can be used to improve the assessment of collision risk by better reflecting the proportion of in-flight populations at risk of collision.2. Data describing the flight heights of birds from surveys of 32 potential offshore wind farm development sites were combined to estimate continuous distributions for 25 marine bird species. Observations of flying birds assigned to discrete height categories were treated as observations from independent multinomial distributions with a shared underlying continuous distribution. This analysis enables calculation of the uncertainty around the estimates of the proportion of the in-flight population at risk and consideration of different turbine designs.3. The mean r(2) for model fit across species was 085, and for seven of the species, good independent model validation (80% of independent observations within 95% confidence intervals) provides some confidence for use of the results at alternative sites.4. All species exhibited positively skewed flight height distributions. These results demonstrate that under the conditions in which the data were collected, raising hub height and using fewer, larger turbines are effective measures for reducing collision risk.5. Synthesis and applications. The methods presented here for modelling continuous flight height distributions provide measures of uncertainty and enable comparison of collision risk between different turbine designs. This approach will improve the accuracy of impact assessments and provide estimates of uncertainty, allowing better evidence to inform decision-making.</p

Modelling flight heights of marine birds to more accurately assess collision risk with offshore wind turbines

1. The number of offshore wind farms is rapidly increasing as they are a critical part of many countries' renewable energy strategies. Quantifying the likely impacts of these developments on wildlife is a fundamental part of the impact assessments required in many regions before permission for developments is granted. A key concern related to wind turbines is the risk of birds colliding with turbine blades. We present a novel method to generate species-specific flight height distributions which can be used to improve the assessment of collision risk by better reflecting the proportion of in-flight populations at risk of collision.2. Data describing the flight heights of birds from surveys of 32 potential offshore wind farm development sites were combined to estimate continuous distributions for 25 marine bird species. Observations of flying birds assigned to discrete height categories were treated as observations from independent multinomial distributions with a shared underlying continuous distribution. This analysis enables calculation of the uncertainty around the estimates of the proportion of the in-flight population at risk and consideration of different turbine designs.3. The mean r(2) for model fit across species was 085, and for seven of the species, good independent model validation (80% of independent observations within 95% confidence intervals) provides some confidence for use of the results at alternative sites.4. All species exhibited positively skewed flight height distributions. These results demonstrate that under the conditions in which the data were collected, raising hub height and using fewer, larger turbines are effective measures for reducing collision risk.5. Synthesis and applications. The methods presented here for modelling continuous flight height distributions provide measures of uncertainty and enable comparison of collision risk between different turbine designs. This approach will improve the accuracy of impact assessments and provide estimates of uncertainty, allowing better evidence to inform decision-making.</p

Advances in cumulative effects assessment and application in marine and coastal management

Quantifying and managing the cumulative effects of human activities on coastal and marine environments is among the foremost challenges in enabling sustainable development in the twenty-first century. As the speed with which these environments are changing increases, there is greater impetus to resolve the evident problems facing governance systems responsible for managing cumulative impacts. Policymakers and regulators recognise the need to assess and manage cumulative effects, as evidenced by widespread legislation requiring cumulative effects assessment (CEA). Yet there is ample evidence that we are not turning the tide in terms of balancing good environmental health with increasing demands of already degraded coastal and marine spaces that are increasingly impacted by climate change. This paper reviews the current state of knowledge regarding scientific and practical advances in CEA, assesses whether these advances are being applied in decision-making and identifies where challenges to implementation exist. Priority research questions are formulated to accelerate the inclusion of effective CEA in marine and coastal planning and management