A bird and small mammal BACI and IG design studies in a wind farm in Malpica (Spain)

Wind farms have shown a spectacular growth during the last 10 years. As far as we know, this study is the first where the relationship between wind power and birds and small mammals have been considered. Before-after control impact (BACI) study design to birds and Impact Gradient (IG) study design to small mammals to test the null hypothesis of no impact of a wind farm were used. In the BACI model Windfarm Area and a Reference Area were considered. Distance from turbines was considered in the IG model. Windfarm installations did not clearly affect bird and small mammal populations. Flight height of nesting and no nesting birds did not show a clear tendency. Small mammals populations suffered high variations in numbers through times by intrinsic population factors. There are many practical problems of detection of human influence on abundances of populations so sampling in the long run can be suggested. © Springer 2005.Peer Reviewe

Doñana wetlands

The Doñana wetlands in SW Spain constitute what remains of the original 180,000 ha of marshland in the Guadalquivir delta. The natural wetlands are protected in the National Park and World Heritage Site (54,252 ha), and include more than 3,000 temporary dune ponds fed mainly from groundwater and 30,000 ha of seasonal marshes dependent on surface flows. They are particularly famous for their avifauna, and hold more wintering waterfowl than any other European wetland. Wading birds exploit surrounding ricefields and fishfarms, and their breeding numbers are increasing. Doñana holds a high diversity of herpetofauna, mammals, invertebrates and plants, with several endemic species. The wetlands have high value for ecotourism and are the setting for the El Rocío pilgrimage. Alien fish and crayfish have had a significant impact. The quantity and quality of water entering the wetlands is under threat from groundwater extraction and other effects of agricultural and urban development.Peer reviewe

Avian mortality from power lines: A morphologic approach of a species-specific mortality

Avian mortality from power lines is a species-specific mortality which affects several vulnerable and endangered species. Identifying the characteristics of species at risk of power line mortality can help solve this conservation problem. The relative abundance of bird species near power lines was compared with records of electrocution and collision casualties from these power lines to identify species-specific death risk as determined by wing morphology. Generally, collision victims were (poor) fliers, while electrocution victims were birds of prey, ravens and thermal soarers. Bird species were categorised by wing morphology and risk of either collision or electrocution. Three categories were identified: species with a high risk of collision, species with a high risk of electrocution and a third mixed group, susceptible to both these causes of death. The variables, weight, wing length, total length and tail length classified 88.6% of the species correctly in these three categories when used in a discriminant analysis. The classification can be used in a predictive model to identify species susceptible to power line mortality. The third mixed group warrants special attention from a conservation point of view because risk is not easily identified and depends on specific behaviour and local circumstances. (C) 2000 Elsevier Science Ltd.Peer Reviewe

Nests of white storks on electric utility towers

Peer Reviewe

Jornadas de investigación sobre la conservación de Doñana: libro de resúmenes

El Espacio Natural de Doñana posee una larga historia en materia de conservación de la Naturaleza. En Doñana se han llevado a cabo investigaciones y actuaciones medioambientales que han sido pioneras en Europa. La Estación Biológica de Doñana (EBD) del Consejo Superior de Investigaciones Científicas (CSIC) coordina la investigación en este espacio natural que ha pasado de una docena de proyectos de investigación en los años setenta a más de 80 proyectos en la última década, dando lugar a más de 2.300 publicaciones científicas. La historia de la EBD-CSIC y la investigación en este espacio protegido se han desarrollado en paralelo. A lo largo de los años, la EBD-CSIC se ha convertido en un centro internacional de investigación dedicada a la ecología y el medio ambiente que abarca áreas de estudio en todo el mundo. Con motivo del 50 aniversario de la EBD, investigadores y gestores que trabajan o han trabajado en Doñana se han reunido para compartir y discutir trabajos de investigación y actuaciones de conservación realizados hasta la fecha, así como propuestas futuras. El presente libro recoge la amplia diversidad de investigadores que han participado en estas jornadas y el amplio abanico de temas que abarcan sus comunicacionesPeer reviewe

Mitigation of raptor electrocution on steel power poles

Differences exist in electrocution rates of birds on wooden versus metal power poles. However, mitigation measures effective on wooden power poles have not solved electrocution problems on metal poles. We examined the effectiveness of 12 experimental modifications of metal power poles to prevent electrocution of raptors. We did so by comparing raptors' perching behavior on paired modified and control poles. We tested 8 of these modifications in the field by comparing avian mortality before/after modification. Modifications were less effective when a 'perch guard' or 'perch' was used than when insulation was used. Small raptors (e.g., tawny owl [Strix aluco], Eurasian kestrel [Falco tinnunculus]) especially were not adequately protected by non-insulation methods. Differences in perching behavior and possibility of electrocution (i.e., wooden vs. steel power poleS) caused differences in effectiveness of modifications. We considered insulation of crossarm braces the most effective and practical modification to reduce electrocution of raptors by metal power poles.Peer Reviewe

Rate of bird collision with power lines: Effects of conductor-marking and static wire-marking

The number of birds killed (per km) by collision with power lines in west-central Spain did not differ between one transmission line and two distribution lines. For all three power lines, we tested the ability of different markers to reduce bird collision by comparing marked spans to unmarked spans along the same power line. A spiral (30 cm × 100 cm) reduced collisions (static wire marking). Black crossed bands (35 cm × 5 cm) were also effective, but not for the vulnerable Great Bustard (Otis tarda) (conductor marking). The third marker, consisting of thin black stripes (70 cm × 0.8 cm), did not reduce mortality (conductor marking). The highest mortality from power-line collision was recorded for the Great and Little Bustard (Otis tarda and Otis tetrax).Peer Reviewe

Common crane and great bustard collision with power lines: Collision rate and risk exposure

The significance of mortality from collision with power lines for several species of birds has been evaluated by collision rates - i.e., number of birds hitting a power line/number of birds crossing a power line. We estimated mortality from power-line collisions for a wintering population of common cranes (Grus grus) and a resident population of great bustards (Otis tarda) in 2 study areas in Spain during 1992-1995. We estimated collision rates at 3.93 x 10-5 for common cranes and at 6.34 x 10-3 for great bustards. Risk exposure (i.e., power-line crossings per unit of time) for common cranes was 714 times greater than for great bustards. Therefore, despite a high collision rate, minimum annual collision mortality for great bustards, present the whole year, was less than for common cranes, present only 4 months - 1.58 and 2.36/km/year, respectively. Collision rate, which defines the chance of collision for a certain bird species, should be combined with risk exposure and population size to evaluate the impact of collision mortality on bird populations.Peer Reviewe

The effects of a wind farm on birds in a migration point: the Strait of Gibraltar.

The interaction between birds and wind turbines is an important factor to consider when a wind farm is constructed. A wind farm and two control areas were studied in Tarifa (Andalusia Province, southern Spain, 30STF590000–30STE610950).Variables were studied along linear transects in each area and observations of flight were also recorded from fixed points in the wind farm. The main purpose of our research was to determine the impact and the degree of flight behavioural change in birds flights resulting from a wind farm. Soaring birds can detect the presence of the turbines because they change their flight direction when they fly near the turbines and their abundance did not seem to be affected. This is also supported by the low amount of dead birds we found in the whole study period in the wind farm area. More studies will be necessary after and before the construction of wind farms to assess changes in passerine populations. Windfarms do not appear to be more detrimental to birds than other man-made structures.Peer Reviewe

Using Wind Tunnels to Predict Bird Mortality in Wind Farms: The Case of Griffon Vultures

Background: Wind farms have shown a spectacular growth during the last 15 years. Avian mortality through collision with moving rotor blades is well-known as one of the main adverse impacts of wind farms. In Spain, the griffon vulture incurs the highest mortality rates in wind farms. Methodology/Principal Findings: As far as we know, this study is the first attempt to predict flight trajectories of birds in order to foresee potentially dangerous areas for wind farm development. We analyse topography and wind flows in relation to flight paths of griffon vultures, using a scaled model of the wind farm area in an aerodynamic wind tunnel, and test the difference between the observed flight paths of griffon vultures and the predominant wind flows. Different wind currents for each wind direction in the aerodynamic model were observed. Simulations of wind flows in a wind tunnel were compared with observed flight paths of griffon vultures. No statistical differences were detected between the observed flight trajectories of griffon vultures and the wind passages observed in our wind tunnel model. A significant correlation was found between dead vultures predicted proportion of vultures crossing those cells according to the aerodynamic model. Conclusions: Griffon vulture flight routes matched the predominant wind flows in the area (i.e. they followed the routes where less flight effort was needed). We suggest using these kinds of simulations to predict flight paths over complex terrains can inform the location of wind turbines and thereby reduce soaring bird mortality. © 2012 de Lucas et al.Peer Reviewe