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

Functional connectivity network between terrestrial and aquatic habitats by a generalist waterbird, and implications for biovectoring

Birds are vectors of dispersal of propagules of plants and other organisms including pathogens, as well as nutrients and contaminants. Thus, through their movements they create functional connectivity between habitat patches. Most studies on connectivity provided by animals to date have focused on movements within similar habitat types. However, some waterbirds regularly switch between terrestrial, coastal and freshwater habitats throughout their daily routines. Lesser black-backed gulls that overwinter in Andalusia use different habitat types for roosting and foraging. In order to reveal their potential role in biovectoring among habitats, we created an inter-habitat connectivity network based on GPS tracking data. We applied connectivity measures by considering frequently visited sites as nodes, and flights as links, to determine the strength of connections in the network between habitats, and identify functional units where connections are more likely to happen. We acquired data for 42 tagged individuals (from five breeding colonies), and identified 5676 direct flights that connected 37 nodes. These 37 sites were classified into seven habitat types: reservoirs, natural lakes, ports, coastal marshes, fish ponds, rubbish dumps and ricefields. The Donana ricefields acted as the central node in the network based on centrality measures. Furthermore, during the first half of winter when rice was harvested, ricefields were the most important habitat type in terms of total time spent. Overall, 90% of all direct flights between nodes were between rubbish dumps (for foraging) and roosts in other habitats, thereby connecting terrestrial and various wetland habitats. The strength of connections decreased between nodes as the distance between them increased, and was concentrated within ten independent spatial and functional units, especially between December and February. The pivotal role for ricefields and rubbish dumps in the network, and their high connectivity with aquatic habitats in general, have important implications for biovectoring into their surroundings. (C) 2019 The Authors. Published by Elsevier B.V

Long-distance migrants vary migratory behaviour as much as short-distance migrants : an individual-level comparison from a seabird species with diverse migration strategies

As environmental conditions fluctuate across years, seasonal migrants must determine where and when to move without comprehensive knowledge of conditions beyond their current location. Animals can address this challenge by following cues in their local environment to vary behaviour in response to current conditions, or by moving based on learned or inherited experience of past conditions resulting in fixed behaviour across years. It is often claimed that long-distance migrants are more fixed in their migratory behaviour because as distance between breeding and wintering areas increases, reliability of cues to predict distant and future conditions decreases. While supported by some population-level studies, the influence of migration distance on behavioural variation is seldom examined on an individual level. Lesser black-backed gulls Larus fuscus are generalist seabirds that use a diversity of migration strategies. Using high-resolution multi-year GPS tracking data from 82 individuals from eight colonies in Western Europe, we quantified inter- and intra-individual variation in non-breeding distributions, winter site fidelity, migration routes and timing of migration, with the objectives of determining how much variation lesser black-backed gulls have in their migratory behaviour and examining whether variation changes with migration distance. We found that intra-individual variation was significantly lower than variation between individuals for non-breeding distributions, winter site fidelity, migration routes and timing of migration, resulting in consistent individual strategies for all behaviours examined. Yet, intra-individual variation ranged widely among individuals (e.g. winter site overlap: 0-0.91 out of 1; migration timing: 0-192 days), and importantly, individual differences in variation were not related to migration distance. The apparent preference for maintaining a consistent strategy, present in even the shortest distance migrants, suggests that familiarity may be more advantageous than exactly tracking current environmental conditions. Yet, variation in behaviour across years was observed in many individuals and could be substantial. This suggests that individuals, irrespective of migration distance, have the capacity to adjust to current conditions within the broad confines of their individual strategies, and occasionally, even change their strategy

Habitat selection and specialisation of herring gulls during the non-breeding season

Understanding both the distribution and habitat use of populations through the annual cycle is vital to understanding how vulnerable species are to environmental change. However, distributions and habitat use can vary among individuals and populations, particularly in generalist species, with variation depending on external environmental factors, such as resource availability. Comprehensive information across multiple populations is important to guide spatial planning of protected areas and is increasingly available for breeding individuals, but it is still lacking for many species, particularly seabirds, during the non-breeding season, especially those with declining populations. We investigated within-species variation in migratory strategies, non-breeding habitat selection and habitat and spatial specialisation in a declining, opportunistic, generalist seabird, the European herring gull Larus argentatus, from multiple breeding colonies across northwest England and southwest Scotland using global positioning system (GPS) tracking during the non-breeding season of 2014/15. Although several individuals stayed within the area of the breeding colony, the majority of individuals migrated in a southerly direction and spent half of the annual cycle (on average 53%) away from the breeding area and kept moving through the non-breeding period. During non-breeding, herring gulls selected mainly marine intertidal, but also a range of anthropogenic terrestrial habitats. However, habitat selection differed between geographical regions, within a geographical region and among individuals. There was a generalist use of non-breeding habitats at the population level, but some habitat specialisation at the individual level that was repeatable through the non-breeding period despite individuals showing low spatial specialisation. The results highlight the importance of intertidal habitat and a mix of alternative foraging habitats in the wintering areas of herring gulls. The results also highlight that habitat selection in an opportunistic generalist can vary even between nearby regions and that appropriate conservation management plans may need to be tailored to regional differences in specific non-breeding areas

Leakage of plastics and other debris from landfills to a highly protected lake by wintering gulls

13 pages, 5 figures, supplementary material https://doi.org/10.1016/j.wasman.2024.01.034.-- Data availability: Data will be made available on requestGeneral context: Gulls ingest plastic and other litter while foraging in open landfills, because organic matter is mixed with other debris. Therefore, gulls are potential biovectors of plastic pollution into natural habitats, especially when they concentrate in wetlands for roosting. Novelty: We quantified, for the first time, the flow of plastic and other anthropogenic debris from open landfills to a natural lake via the movement of gulls. We focused on Fuente de Piedra, an inland closed-basin lake in Spain that is internationally important for biodiversity. Methodology: In 2022, we sampled gull pellets regurgitated in the lake by lesser black-backed gulls Larus fuscus that feed on landfills, as well as their faeces, then characterized and quantified debris particles of ≥0.5 mm. By combining GPS and census data from 2010 to 2022, together with plastic quantification based on FTIR-ATR analysis, we estimated the average annual deposition of plastic and other debris by the wintering gull population into the lake. Main results: 86 % of pellets contained plastics, and 94 % contained other debris such as glass and textiles. Polyethylene (54 %), polypropylene (11.5 %) and polystyrene (11.5 %) were the main plastic polymers. An estimated annual mean of 400 kg of plastics were moved by gulls into the lake. Only 1 % of plastic mass was imported in faeces. Discussion: Incorporating the biovectoring role of birds can provide a more holistic view of the plastic cycle and waste management. Biovectoring is predictable in sites worldwide where gulls and other waterbirds feed in landfills and roost in wetlands. We discuss bird deterrence and other ways of mitigating debris leakage into aquatic ecosystemsProject funding was provided by the Junta de Andalucía (proyecto de I + D + i PY20_00756 “GuanoPlastic”) and H2020 - AquaticPollutants Joint Transnational Call 2020/Agencia Estatal de Investigación (project PCI2021-121938/AEI/10.13039/501100011033 “Pairwise”), both to AJG). VMV was also funded with a Margarita Salas grant 2022 from Next Generation EU. [...] For UK sites, this work was funded by the Department for Energy Security and Net Zero (DESNZ), through the Offshore Energy Strategic Environmental Assessment research programme, with the contract managed by John Hartley (Hartley Anderson Ltd), and was further funded by Ørsted, and supported by the Marine Renewable Energy and the Environment (MaREE) project (funded by Highlands and Islands Enterprise, the European Regional Development Fund and the Scottish Funding Council)With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

Breeding and foraging ecology of guillemots and razorbills : a comparison of two pursuit-diving seabirds

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