Modelling and reviews
Collision Risk Modelling
The Collision Risk Models (CRMs) used in estimating the number of birds that might collide with proposed wind farms are sensitive to a number of metrics, including the flux of birds entering the area of the wind farm, flight height of species, avoidance behaviour and flight heights. Working with industry and government, our work has improved the evidence base on these metrics, drawing data from multiple sources (boat surveys, digital aerial surveys, LiDAR, tracking) and examining how they are best incorporated in analytical models.
Modelling distributions of birds at sea
As the number and size of offshore wind farms increase, novel technologies and innovative analytical approaches are needed in order to properly assess each project’s environmental impact. Working with Forewind Ltd, we combined data from boat and digital aerial surveys to produce robust models describing the spatio-temporal distribution of a range of sea bird species in the Dogger Bank Offshore Wind Farm Zone.
On behalf of The Crown Estate, we are working with partners to map spatial patterns in seabird flight heights, a key parameter in relation to assessing collision risk, using LiDAR data. Using bespoke analyses we aim to maximise the value of data collected using novel technologies.
It is important to place predictions of the impacts associated with developments in context. There is a wide range of approaches to predict the population-level consequences of the impacts associated with wind farms. However, many of these approaches have been open to challenge, resulting in increased uncertainty and costs in the decision-making process. Building on our experience in avian demography and population modelling, we have been working with governmental advisors and regulators to develop robust methodologies for assessing the population-level impacts of wind farms, and other renewables, on bird populations.
Understanding management actions
Our research is frequently applied to understanding the impacts of developments and land-use interventions on species and habitats. For example, UK estuaries are internationally important for waterbirds that rely on the high densities of invertebrate food species present. Oystercatchers on the Wash rely on cockles and mussels that are also harvested commercially. An analysis of the survival rates in relation to shellfish availability has helped develop a sustainable management strategy for the fishery.
Similarly, a study following displaced Redshank in the Cardiff Bay barrage development demonstrated a marked reduction in their survival. These two cases illustrate our rigorous, evidence-based approach.
New developments cannot be considered in isolation because impacts are not restricted to one particular season. Additionally, migratory birds that cross multiple country borders can be at an increased risk compared to non-migratory species. For birds that range widely, individuals may be affected by a number of different wind energy installations, so the total risk of collision or displacement will be greater than for just the wind farm in question.
This is an extremely important consideration, as regulators require cumulative effects to be taken into account. However, as these can be difficult to determine and require a wider perspective, they have been relatively underreported in assessments. BTO Consulting utilises the BTO’s national bird monitoring data and large tracking datasets and are in an ideal position to develop new ways of assessing cumulative impacts.
BTO Consulting has a vision of a world in which nature conservation and sustainable development are founded on evidence-based decision-making, and in which society understands, values and contributes to that process.Dr James Pearce-Higgins, Director of Science
By collecting and reviewing available evidence BTO Consulting is able to produce valuable synthesis and insights to inform management decisions. Examples of some of the many reviews we have undertaken include:
Cumulative Impact Assessments - Onshore Wind Industry
Working with the University of the Highlands and Islands, the BTO reviewed approaches to Cumulative Impact Assessment across the onshore wind industry. This work showed that whilst industry practice relied on relatively qualitative descriptions and simplistic approaches, more sophisticated methods have been developed by academic researchers which may be more appropriate to use in some circumstances.
Mechanisms of climate change impacts on biodiversity
Climate change is a key threat to biodiversity. This BTO-led assessment by global experts reviewed the mechanisms that underpin these impacts, and provided critical evidence about the importance of altered species interactions, which has been highly cited since.
Species information dossiers on vulnerability to wind farms
Commissioned by the Scottish Windfarm Bird Steering Group, the BTO created seventeen species dossiers to examine the relationship between specific bird populations and wind farms, and to act as a platform for dialogue between the renewables industry, conservation organisations and government on these issues.
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Understanding the Impacts of Wind Farms on Birds
For more information about the BTO’s work on wind farms, contact aonghais.cook [at] bto.org.