In recent years the British Ornithologists’ Union has covered various important issues in applied ornithology in its conferences. This meeting not only covered an important topic, but brought the ornithologists together with experts on the technologies involved and with policy-makers. It was a fruitful weekend.

Brian Huntley (University of Durham) set the scene with an overview of the potential impacts of climate change on birds. Under current trends, atmospheric CO2 will reach concentrations not seen for tens of millions of years and global temperatures will be higher than they have been for millions of years. Organisms may react to such environmental changes by evolutionary adaptation but the evidence from the fossil record of the Quaternary is that they are more likely to shift their ranges or to go extinct. Given that the current pace of climate change is greater than at any previous time in the Quaternary, adaptation is even less likely than in the past. By determining the ‘climate envelopes’ of current ranges of European birds, it is possible to determine by how much ranges are likely to shift under likely scenarios of climate change over the rest of the century. Shifts will be big, some up to 1000 km, with the predicted ranges of a quarter of the modelled species overlapping the current ranges by less than 10%. The likelihood of extinction is clearly high for species with such small overlaps between current and modelled ranges. Given that habitats may not shift in exactly the same way as climate, extinction is even more likely. Palearctic–African migrants will be especially vulnerable, because distances between potential breeding and wintering ranges will generally increase. A poster by Mark Rehfisch (BTO) and colleagues showed that, on top of the usual fluctuations in distribution occasioned by habitat and population changes, there have already been substantial shifts in the distribution of many shorebirds overwintering in Britain, associated with warmer winters.

John Lanchbery (RSPB) reviewed how we may moderate the extent of climate change, asserting that we needed both greater efficiency in our use of energy and cleaner technologies, obtained especially through the use of renewable energy sources. (There was little discussion at the conference of the third and most distasteful route: using less energy by doing less.) He argued that we need to be exploring all possible technological solutions, even those that were currently far from practical implementation. Wind, being currently nearest to the market, will be a major contributor. In officially opening the conference, ornithologist and government minister Elliot Morley confirmed this, predicting that wind would make up 70% of the UK's renewable energy. He pointed to the dilemma underlying the whole conference: that, in order to moderate climate change, we need to use technologies that might themselves have adverse environmental impacts; this means that the development of these technologies needs to be in ways that minimize their adverse effects. In discussion, he stated that ‘air transport has got off scot-free for far too long’ and that to reduce its impacts we need to persuade people to change their behaviour and to draw the aviation industry into carbon-trading. Catherine Mitchell (Warwick Business School), reviewing the policy drivers of renewable energy options in the UK, pointed out that the Renewables Option, the UK Government mechanism for supporting renewables, is unique in Europe in being market-based. That is why wind dominates developments in Britain: there is little support for technologies that are less close to market. She argued that the evidence is that market-based policies alone cannot deliver these other technologies. That is why, despite the visionary energy policy formulated by Government in 2003, the UK is not delivering the required changes to the extent of many of its neighbours.

Because it is rolling out most quickly and has some obvious impacts on birds, wind technology dominated the conference. Richard Ford and Chris Tomlinson (both British Wind Energy Association) presented some of the rapid technical developments of wind turbines that have occurred in the last decade, improving efficiency and reducing some adverse features. Turbines operate 80% of the time on average in Britain and are efficient, generating enough energy in 3–5 months to balance that involved in their manufacture. Current industry projections suggest that the government target for renewable energy in 2010 will be matched by 1800 turbines, split equally between onshore and offshore sites.

Alan Drewitt (English Nature) and Rowena Langston (RSPB) reviewed the potential effects of wind turbines on birds. They can be barriers to bird movement and their construction may cause habitat loss but these appear generally to be insignificant problems. However, the risk of collision, though low for individual birds, is significant when birds and turbines are concentrated in the same place. Colin Pennycuick (University of Bristol), glider pilot and doyen of bird flight researchers, showed how we need to understand how birds use the airspace if we are to reduce the risk of collision. What conditions affect flying birds on the local scale, such as their seeking rising air? What affects choice of migration routes? Where are migration concentrations? How high do birds fly under different conditions? We already know enough to advise generally against putting turbines in gaps between hills (through which birds fly) or building turbine towers with lattice-work (which makes attractive perches) but most advice will have to be site-specific. Mike Madders (Natural Research), pointing out that the widely used models of collision risk were worthless unless based on good data, presented case studies of data-gathering around onshore developments. Our poor knowledge of actual collision risk and of the way birds close to turbines avoid them (or fail to do so) was frequently referred to during the meeting, as a significant gap in knowledge.

Madders also presented some evidence that raptors avoid wind farms, which set the scene for Alv Ottar Folkested's (Norwegian Sea Eagle Project) presentation of work from an intensive study on the Smøla archipelago (Norway), where two wind farms have been sited in an area with an extraordinarily high density of White-tailed Eagles Haliaeetus albicilla. The birds seem to have avoided collisions yet are prepared to nest within 1 km of the wind farms, though for a species with such a slow natural rate of population turnover even small changes in breeding success or mortality are significant, so more data are needed. The disturbance associated with wind farms is obviously important during construction but it may also be high afterwards: Tony Fox (NERI, Denmark) pointed out that an offshore farm of about 90 turbines in Denmark generated boat traffic almost every day. Birds avoided this site at distances of 1–4 km, though whether this has any adverse effects on their populations is unclear.

The need for data was a recurring theme. The refined behaviour-based models discussed by Richard Caldow (Centre for Ecology & Hydrology) have been remarkably successful in predicting (or ‘postdicting’) the effects of habitat changes on bird populations but they can only be effective if fed with good data on the distribution of available food resources. Caldow and colleagues have been laboriously amassing this for Common Scoters Melanitta nigra in Liverpool Bay, to assess the likely impact of wind farms there.

The risks are clearly greatest where birds concentrate, such as the Tehuantepec Isthmus (Mexico), through which four million raptors pass annually and where wind farms are planned (poster by Rafael Villegas-Patraca and colleagues – Instituto de Ecologia AC. Departamento de Ecologia Aplicada, Mexico). The situation in Germany, reviewed by Ommo Hüppop (Vogelwarte Helgoland), is relevant here: the country is the world leader in developing the use of wind turbines, with applications for 12 000 turbines currently, and has hundreds of millions of birds migrating over its seas every year. Using visual and acoustic observations, radar and thermal imaging, much new information has been obtained that has been built into models to estimate some of the risks.

The use of technology to extend our powers of data-gathering was the theme of several talks and posters: the Thermal Animal Detection System (Mark Desholm – NERI, Denmark), radiotelemetry (Martin Perrow and colleagues – ECON Ecological Consultants) and radar (Mark Brown, Richard Walls – both Central Science Laboratory). Perrow showed that Little Terns Sterna albifrons may travel up to 25 km on a single foraging bout and Walls that Greater White-fronted Geese Anser albifrons may fly more at night than previously thought, confirming how little we still know about the daily lives of birds.

An important feature of the conference was the final session devoted to reviewing our current state of knowledge and identifying research and monitoring needs, this also being covered in the presentations by Fox and by Drewitt & Langston. At its simplest, we need more data, especially about the actual risks of collision and about bird movements over the sea. It was thought that if governments wish to see these technologies develop in the least damaging way they will need to invest more public funds in the research. Of course, we already have much information on some things (through schemes such as the Wetland Bird Survey, the subject of a poster from Andy Musgrove and Mark Rehfisch – BTO), and what data we have can be used to assess both likely problems and potential solutions (with examples in posters by Rob Luckings and by Richard Evans (RSPB)). Each Environmental Impact Assessment needs, however, to be site-specific and needs to be supported by at least 2 or 3 years of detailed observation at the site (including nocturnal observations). During and after construction there needs to be monitoring, the results of which must be published so that lessons can be learnt. (The need for better information-sharing was another important conclusion.) Common standards for assessment and monitoring need to be developed to reduce the use of inadequate methods. The conference also identified a need for more study of potential mitigation measures, such as locating turbines in sites where collision is less likely and giving them UV-reflective coatings to make them more visible to birds. A poster by Jesús Fernandez Majías and Manuel Lóbon Garcia (both from Spain) showed how wardens at wind farms can reduce the number of collisions by alerting the operators when birds are in the area so that turbines can be shut down, and by removing carrion that might otherwise attract them. More such experiments are needed.

The conference also flagged up that we know even less about the potential side-effects of some of the other renewable technologies, though this is not true of traditional hydro power, reviewed by Alastair Gill and Andrew Brown (both Npower Renewables). Based on large reservoirs, this is associated with environmental disturbance during construction and with reduced flows in rivers. Particularly if under tighter regulatory regimes (described by Paul Copestake – Scottish Environmental Protection Agency), hydro power is unlikely to expand much beyond the 2% of UK energy that it provided in 2004. What expansion there is will be in run-of-river schemes, which use the existing current rather than impoundment to generate power and are small in scale. But even these usually require some diversion of the stream, so are not without potential environmental impacts.

Tidal power has much greater potential for expansion. In the early 1990s there was much interest in the UK in tidal barrages, lagoons into and out of which water moves, potentially generating power during both parts of the tidal cycle. Nigel Clark (BTO) described the results of studies into the potential effects of such barrages on estuarine birds –‘potential’ because the ecological impacts of the only large barrage to have been built in Europe (on the Rance estuary) were not studied until 10 years after it was built, so there was no opportunity for the before-and-after observations that are essential to determine the actual impacts of development. Barrages might affect birds by displacing them, by reducing the area or time available for feeding, by changing the sediment regime (which affects the invertebrates on which the birds feed), or by reducing the flooding of saltmarshes. The approach of Clark and his colleagues has been to consider the likely changes in the structure of the estuary that would follow construction of a barrage and, based on knowledge of how birds currently use estuaries of various physical characteristics, to predict the effects on birds of the changes. The approach is generic but the predictions are estuary-specific. This approach also allows one to identify changes to the design, or other engineering solutions, to reduce the effects on bird populations.

Another way of harvesting power from tides is to rely on natural currents to drive turbines. Peter Fraenkel (Marine Current Turbines) suggested that, although this technology is in its infancy, it is developing rapidly, costs are falling and 20% of UK energy demand could be met through installations at only the eight best sites around the coast. However, while the small scale of individual installations and features of their design suggest that their ecological effects may be small, the technology is being developed in such a small way that there have been no real studies of such impacts.

Wave power is another technology that is being developed on a small but expanding scale. In theory, as presented by Michael Hay (British Wind Energy Association), waves could supply more than the whole electricity demand in the UK, though in practice the proportion is likely to be no more than 15%. Again, little is known of its likely environmental effects, though these could be small.

The most obvious way of harvesting energy renewably is to go back to the old technology – photosynthesis. That is, grow biofuels. Rufus Sage (Game Conservancy Trust) and his colleagues showed that this may deliver benefits for birds, especially if the exact management of the crops is carefully considered. However, this is not a magic solution to our problems. Woody material is an excellent energy source for Combined Heat and Power plants and is a useful way of reducing greenhouse gas emissions. However, most transport systems (which are major energy users) currently use liquid fuels and at present it is not easy to produce these from woody materials. Transport can be fuelled by biodiesel (from oil crops, such as rape) or bioethanol (from the fermentation of sugars or starches from, for example, sugar-beet or wheat). Unfortunately, if the crops involved are grown using modern agricultural methods (which rely on massive inputs of fossil fuels, both direct and indirect), this is not an effective way to reduce greenhouse gas emissions. Furthermore, as pointed out by Malcolm Fergusson (Institute for European Environmental Policies), who reviewed biofuels for the conference, if the whole arable area of the UK were planted with oilseed rape, this would not be enough to fuel all the lorries on our roads, let alone the rest of the transport system.

This was a valuable meeting in bringing together ecologists, technologists and policy experts. Many gaps in knowledge were identified, as were the ways to fill them. Scientists and technologists are making their contribution to a brighter future. Can politicians make theirs?


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  2. Acknowledgments

Wind, Fire and Water: Renewable Energy and Birds was a conference organized by Rowena Langston (RSPB) and Steve Dudley (BOU) on behalf of the British Ornithologists’ Union.

The BOU is grateful to the individual speakers and their respective organizations for presenting their work at the conference.

The BOU is grateful to Richard Evans (RSPB), Guy Anderson (RSPB), Sam Gardner (RSPB) and Alison McLennan (RSPB) for their help during the conference.

The proceedings of this conference will be published as an online-only supplement of Ibis thanks to support from the RSPB, Department of Trade and Industry, Renewables Advisory Board, British Wind Energy Association and English Nature.