Prevalence of Haemosporidian Parasites in an Arctic Breeding Seabird Species-The Red-Throated Diver (Gavia stellata).

Haemosporida, vector-transmitted blood parasites, can have various effects and may also exert selection pressures on their hosts. In this study we analyse the presence of Haemosporida in a previously unstudied migratory seabird species, the red-throated diver Gavia stellata. Red-throated divers were sampled during winter and spring in the eastern German Bight (North Sea). We used molecular methods and data from a related tracking study to reveal (i) if red-throated divers are infected with Haemosporida of the genera Leucocytozoon, Plasmodium and Haemoproteus, and (ii) how infection and prevalence are linked with the breeding regions of infected individuals. Divers in this study were assigned to western Palearctic breeding grounds, namely Greenland, Svalbard, Norway and Arctic Russia. We found a prevalence of Leucocytozoon of 11.0% in all birds sampled (n = 45), of 33.0% in birds breeding in Norway (n = 3) and of 8.3% in birds breeding in Arctic Russia (n = 25). For two birds that were infected no breeding regions could be assigned. We identified two previously unknown lineages, one each of Plasmodium and Leucocytozoon. Haemosporida have not been detected in birds from Greenland (n = 2) and Svalbard (n = 2). In summary, this study presents the first record of Haemosporida in red-throated divers and reports a new lineage of each, Plasmodium and Leucocytozoon GAVSTE01 and GAVSTE02, respectively.

Real-time predictions of seabird distribution improve oil spill risk assessments.

Current knowledge of the distribution of sensitive seabirds is inadequate to safeguard seabird populations from impacts of oil spills in the Arctic. This gap is mainly driven by the fact that statistical models applied to survey data are coarse-scale and static with limited documentation of the distributional dynamics and patchiness of seabirds relevant to risk assessments related to oil spills. This paper describes a dynamic modelling framework solution for prediction of fine-scale densities and movements of seabirds in close-to-real time using fully integrated 3-D hydrodynamic models, dynamic habitat suitability models and agent-based models. The modelling framework has been developed and validated for the swimming migration of Brünnich's Guillemot Uria lomvia in the Barents Sea. The results document that the distributional dynamics of Brünnich's Guillemot and other seabird species to a large degree can be simulated with in-situ state variables and patterns reflecting the physical meteorology and oceanography and habitat suitability.

Satellite telemetry and digital aerial surveys show strong displacement of red-throated divers (Gavia stellata) from offshore wind farms.

Expansion of offshore wind energy is vital for the reduction of CO2 emissions. However, offshore wind farms may negatively impact the environment without proper planning. Here we assess the robustness of the conclusions of earlier studies that the strictly protected red-throated diver, Gavia stellata, is strongly displaced from wind farms in the German Bight (North Sea). We modelled the distribution of divers based on two independent data sets, digital aerial surveys and satellite telemetry, in relation to the dynamic offshore environment and anthropogenic pressures. Both data types found that divers were strongly displaced from wind farms in suitable habitat. The displacement effect gradually decreased with distance from the wind farms (being very strong up to 5 km away), but a significant effect could be detected up to 10-15 km away. The telemetry data further indicated that the displacement distance decreased with decreasing visibility. The displacement distance was also shorter during the day than during the night, potentially as a response to aviation and navigation lights of the wind farms. These findings should be taken into consideration in marine spatial planning to avoid cumulative impacts on red-throated diver populations.

A novel approach for assessing effects of ship traffic on distributions and movements of seabirds.

Marine habitats are nowadays strongly affected by human activities, while for many species the consequences of these impacts are still unclear. The red-throated diver (Gavia stellata) has been reported to be sensitive to ship traffic and other anthropogenic pressures and is consequently of high conservation concern. We studied red-throated divers in the German Bight (North Sea) using satellite telemetry and digital aerial surveys with the aim of assessing effects of ship traffic on the distribution and movements of this species during the non-breeding season. Data from the automatic identification system of ships (AIS) were intersected with bird data and allowed detailed spatial and temporal analyses. During the study period, ship traffic was present throughout the main distribution area of divers. Depending on impact radius, only small areas existed in which ship traffic was present on less than 20% of the days. Ship traffic was dominated by fishing vessels and cargo ships, but also wind farm-related ships were frequently recorded. Red-throated divers were more abundant in areas with no or little concurrent ship traffic. Analysis of aerial survey data revealed strong effects of ship speed on divers: in areas with vessels sailing at high speed only a slow resettlement of the area was observed after the disturbance, while in areas with vessels sailing at medium speed the resettlement was more rapid during the observed time period of 7 hours. Data from satellite-tracking of divers suggest that large relocation distances of individuals are related to disturbance by ships which often trigger birds to take flight. Effective measures to reduce disturbance could include channeled traffic in sensitive areas, as well as speed limits for ships traveling within the protected marine area.

Outstanding Challenges in the Transferability of Ecological Models.

Predictive models are central to many scientific disciplines and vital for informing management in a rapidly changing world. However, limited understanding of the accuracy and precision of models transferred to novel conditions (their 'transferability') undermines confidence in their predictions. Here, 50 experts identified priority knowledge gaps which, if filled, will most improve model transfers. These are summarized into six technical and six fundamental challenges, which underlie the combined need to intensify research on the determinants of ecological predictability, including species traits and data quality, and develop best practices for transferring models. Of high importance is the identification of a widely applicable set of transferability metrics, with appropriate tools to quantify the sources and impacts of prediction uncertainty under novel conditions.

Patterns of migrating soaring migrants indicate attraction to marine wind farms.

Monitoring of bird migration at marine wind farms has a short history, and unsurprisingly most studies have focused on the potential for collisions. Risk for population impacts may exist to soaring migrants such as raptors with K-strategic life-history characteristics. Soaring migrants display strong dependence on thermals and updrafts and an affinity to land areas and islands during their migration, a behaviour that creates corridors where raptors move across narrow straits and sounds and are attracted to islands. Several migration corridors for soaring birds overlap with the development regions for marine wind farms in NW Europe. However, no empirical data have yet been available on avoidance or attraction rates and behavioural reactions of soaring migrants to marine wind farms. Based on a post-construction monitoring study, we show that all raptor species displayed a significant attraction behaviour towards a wind farm. The modified migratory behaviour was also significantly different from the behaviour at nearby reference sites. The attraction was inversely related to distance to the wind farm and was primarily recorded during periods of adverse wind conditions. The attraction behaviour suggests that migrating raptor species are far more at risk of colliding with wind turbines at sea than hitherto assessed.