Manuela de Lucas

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.

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.

Why birds with deferred sexual maturity are sedentary on islands: a systematic review.

Background Island faunas have played central roles in the development of evolutionary biology and ecology. Birds are among the most studied organisms on islands, in part because of their dispersal powers linked to migration. Even so, we lack of information about differences in the movement ecology of island versus mainland populations of birds. Methodology/Principal Findings Here we present a new general pattern indicating that large birds with deferred sexual maturity are sedentary on islands, and that they become so even when they are migratory on the mainland. Density-dependent variation in the age at first breeding affects the survivorship of insular populations and this, in turn, affects the movement ecology of large birds. Because density-dependent variation in the age of first breeding is critical to the long-term survival of small isolated populations of long-lived species, migratory forms can successfully colonize islands only if they become sedentary once there. Analyses of the movement ecology of continental and insular populations of 314 species of raptors, 113 species of Ciconiiformes and 136 species of passerines, along with individual-based population simulations confirm this prediction. Conclusions This finding has several consequences for speciation, colonization and survival of small isolated population of species with deferred sexual maturity.

Productivity is related to nest site protection and nesting substrate in a German Osprey population

AbstractThe Osprey (Pandion haliaetus) is an emblematic example of conservation. Currently, the species is progressively recovering in population size and range after dramatic reductions as a consequence of human persecution and the use of pesticides in the nineteenth and twentieth centuries. Here, we analysed the population trend and productivity in relation to the nesting substrate (artificial structures or trees) and the protection status of the nest location (inside or outside protected areas) in the eastern German population of Ospreys. The Osprey population steadily grew during the study period (2000–2009), accompanied by the increased use of artificial structures for nesting, possibly due to the scarcity of suitable natural nest sites in the region. Pairs nesting in trees showed higher variance in productivity than those nesting on artificial supports during the study period. Further, the productivity recorded in Ospreys nesting on natural sites decreased during the study period, regardless of the protection status of the nest location, whereas it did not vary for pairs nesting on artificial structures. The productivity of Ospreys was also related to the protection status of the nest location since pairs breeding inside protected areas, either in natural or on artificial nest sites, showed higher productivity than pairs nesting outside protected areas. These findings suggest that the protection of the nest location and the type of substrate used for nesting are relevant factors underlying the breeding performance in this Osprey population and are therefore key to its management.ZusammenfassungReproduktion des Fischadlers hängt vom Schutzstatus der Horstumgebung und vom Nistplatztyp ab Der Fischadler (Pandion haliaetus) ist ein Wahrzeichen für erfolgreichen Artenschutz. Nach dramatischem Rückgang durch menschliche Verfolgung und Pestizide im 19. und 20. Jahrhundert stieg die Populationsgröße in den letzten Jahrzehnten wieder an, und in vielen Regionen hat sich auch das Areal vergrößert. Hier analysieren wir den Populationstrend und die Reproduktion von Fischadlern in Ostdeutschland in Abhängigkeit vom Nistplatztyp (künstliche Strukturen vs. Bäume) und dem Schutzstatus des Nistplatzes (innerhalb vs. außerhalb von Naturparks, Biosphärenreservaten und einem Nationalpark). Die Fischadlerpopulation ist im betrachteten Zeitraum 2002–2009 stetig gestiegen, wobei—wohl in Ermangelung geeigneter alter Nistbäume—zunehmend anthropogene Strukturen, vor allem Gittermasten genutzt werden. Paare, die auf Bäumen nisten, zeigen eine höhere Varianz in der Zahl der Nachkommen als Paare, die auf künstlichen Strukturen nisten. Die Reproduktion der Fischadler auf natürlichen Nistplätzen hat im Verlauf der Untersuchungszeit abgenommen, unabhängig vom Schutzstatus der Umgebung. Dagegen hat sich Reproduktion der Fischadler auf künstlichen Strukturen nicht verändert. Paare innerhalb von Schutzgebieten hatten eine höhere Produktivität als Paare außerhalb von Schutzzonen, egal ob auf natürlichen oder künstlichen Nistplätzen. Die Ergebnisse weisen darauf hin, dass Schutzgebiete und der Nistplatztyp für die Reproduktion in dieser Fischadlerpopulation und ihr Management relevant sind.

Dogs are the main species involved in animal-vehicle collisions in southern Spain: Daily, seasonal and spatial analyses of collisions

Animal-vehicle collisions have become a serious traffic safety issue. Collisions have steadily increased over the last few decades, as have their associated socio-economic costs. Here, we explore the spatial and temporal patterns of animal-vehicle collisions reported to authorities in the province of Seville, southern Spain. Most animal-vehicle collisions involved domestic animals (>95%), particularly dogs (>80%), a pattern that sharply contrasts with that found in other Spanish and European regions, where collisions are mostly caused by game species. Dog-vehicle collisions were related to the traffic intensity of the roads and they were more frequent around dawn and dusk, coinciding with the peaks of activity of dogs. This pattern was consistent throughout the week, although on weekends there were fewer collisions due to lower traffic density at those times. These findings suggest that the aggregation of dog-vehicle collisions around twilight likely resulted from a combined effect of the activity peaks of dogs and traffic density. Seasonally, collisions increased in autumn and winter, coinciding with the period of intense hunting activity in the region. Further, during autumn and winter, rush hour partly overlaps with twilight due to longer nights in comparison with summer and spring, which may contribute to the increased rate of dog-vehicle collisions in these seasons. Spatially, satellite images of nighttime lights showed that dog-vehicle collisions were clustered near urban areas. Overall, the high incidence of stray dogs involved in animal-vehicle collisions highlights a road safety issue with this type of animals in the region.

Impact of wind farms on soaring bird populations at a migratory bottleneck

Collision with turbines at wind farms is expected to have a greater impact on birds at particular sites where high concentrations of individuals occur, such as migration bottleneck areas. The Strait of Gibraltar (southern Spain) has long been recognized as the most important bottleneck in western Europe for soaring bird migration. Moreover, this area is within one of the most important potential areas for wind energy generation in Spain. Here, we examine monthly migratory soaring bird abundance in relation to long-term avian mortality rates at 21 wind farms located near the Strait of Gibraltar using zero-inflated hurdle negative binomial and gamma models. Best fit models included an effect of season in the collision mortality rates and in the proportion of adult individuals within the total deaths. However, monthly bird abundance was not directly related to the number of fatalities over the year. The accumulated fatalities during autumn migration constitute a small percentage (1%) of the total migrating population size. Moreover, mortality peak during autumn migration is largely attributable to juvenile birds. In contrast, the number of fatalities coinciding with the breeding period constitutes a substantial proportion (6%) of the local population, and it involved substantial losses among adult birds. Our results show that wind farms probably have an individually low impact on the migratory population of soaring birds. On the contrary, annual losses among adult local birds are remarkably high considering the small size of the local populations, and they may have population level effects.