Distribution of seabirds and waterbirds in the German Baltic Sea throughout the year

Die Verbreitungsmuster ausgewählter See- und Wasservogelarten in den Offshore-Bereichen der deutschen Ostsee werden erstmals für die vier Jahreszeiträume Frühjahr, Sommer, Herbst und Winter dargestellt. Dabei zeigen sich bei den einzelnen Arten sowohl räumliche als auf saisonale Verbreitungsunterschiede. Die deutschen Ostseewässer stellen für See- und Wasservögel ein wichtiges Rast-, Mauser- und Überwinterungsgebiet dar, einige Arten kommen in international bedeutsamen Konzentrationen vor. Für das im Mai 2004 an die EU-Kommission gemeldete Seevogelschutzgebiet „Östliche Pommersche Bucht“ im Ostteil der deutschen Ostsee werden erstmals aktuelle Bestandszahlen der wichtigsten Seevogelarten vorgestellt. Für im Untersuchungsgebiet nur selten auftretende Seevogelarten werden die Gesamtzahlen aller Nachweise aus den Schiffszählungen angegeben. Ziehende oder nur im Küstenbereich vorkommende Wasservogelarten werden lediglich namentlich aufgelistet. In Ergänzung zu früheren Publikationen liefert der vorliegende Artikel umfassende Informationen über das Vorkommen und die jahreszeitlichen Unterschiede der häufigen See- und Wasservogelarten im Offshore-Bereich der deutschen Ostsee.The German Baltic Sea is a very important area for seabirds and waterbirds. 38 species are regularly found in coastal or offshore waters. Many of them occur in international important concentrations and are subject to various conservation-related conventions and directives, especially the EU Birds Directive and the African-Eurasian Waterbird Agreement (AEWA). From 2000 to 2005, several research projects were dedicated to describe and analyse the distribution and abundance of seabirds in the offshore area in the German Baltic Sea at high spatial and temporal resolutions. In this study, we present for the first time the distribution of seabirds and waterbirds in the German Baltic Sea throughout the year, based on transect counts from ships. The main focus is on the offshore areas. For the most numerous species we present the distribution for the four seasons summer, autumn, winter and spring, defined species-specific. The maps clearly show spatial and temporal differences in the distribution of the various species. While Red-breasted Mergansers, Great Crested Grebes or Great Cormorants occur predominantely close to the coast, Red-necked Grebes, Slavonian Grebes and Common Guillemots, among others, prefer offshore-areas. The most numerous and characteristic species are the sea ducks Common Eider, Long-tailed Duck, Common Scoter and Velvet Scoter. They prefer areas with low water depth along the coast or on shallow banks in the offshore area. While Common Eiders occur chiefly in the western parts of the German Baltic Sea, Velvet Scoters are mainly found in the eastern parts. Both species have high densities in the winter half-year but only small numbers during summer. Long-tail Ducks and Common Scoters are distributed over large areas of the German Baltic Sea, but while the former species occurs in the winter half-year only, the latter species is present throughout the whole year. Gulls are widespread throughout the study area and show only local and/or short-term concentrations. Aggregations are often in the vicinity of high fishing activities. The most frequent gull species is the Herring Gull. Terns occur only in very small numbers in the German Baltic Sea, with Black Terns exhibiting small concentrations in the eastern part during late summer. Species that occur predominantly in coastal areas of the German Baltic Sea are not presented in detail. However, for Mute Swan, Greater Scaup, Common Goldeneye and Goosander we present maps for the winter half-year (October-April), as the nearshore distribution of these species sometimes extent into offshore areas. For species occuring only seldom within the study area we present a list with the total number of individuals seen during the surveys. Coastal or migrating waterbird species are only named. Together with previously published information on the distribution of seabirds and waterbirds in the German Baltic Sea, available mainly for the winter and spring periods, this study gives a comprehensive overview about the spatial and temporal distribution of the most numerous and widespread seabirds and waterbirds in the German Baltic Sea. In addition, current population estimates of these species are given for the recently designated Special Protection Area “Pommersche Bucht” in the Exclusive Economic Zone (EEZ) of the eastern part of the German Baltic Sea

Investigating a seabird hotspot : factors influencing the distribution of birds in the southern Baltic Sea

The southern Baltic Sea in northeastern Europe has been described as one of the most important areas for seabirds in the Western Palaearctic, based on extraordinary high numbers of birds occurring in the area particularly during the winter half-year. Most studies, however, only comprise information about the distribution of birds, while the factors and mechanisms causing the observed distribution patterns are only seldom addressed. Prey distribution and abundance and foraging strategies are certainly the most decisive factors determining the distribution and habitat choice of seabirds at sea, but diet preferences are unknown for many species. However, an extensive understanding of the functionality between seabirds and their marine environment is essential not only to be able to assess natural changes in numbers and distribution, but to evaluate the risks posed by anthropogenic activities as human pressure on marine ecosystems has increased enormously over the last decades. This thesis overcomes the lack of comprehensive knowledge about the ecology of birds in the brackish environment of the southern Baltic Sea and provides basic information on bird-habitat-relationships, on interspecific interactions and on diet preferences of selected species. Furthermore, set net fisheries as a particularly high threat to birds in the southern Baltic Sea are exemplarily outlined in this thesis. The methods to address the study objectives comprise ship-based Seabirds at Sea surveys to reveal spatial and temporal distribution patterns, mathematical modelling to analyse these patterns with regard to habitat parameters and species’ interactions, analyses of stomach contents for dietary studies and the development of an approach to evaluate the conflict between birds and human impacts. The avifauna of the brackish Baltic Sea strongly differs from truly marine systems: while pelagic species are only represented by auks, the bird community is dominated by species that breed in (arctic) freshwater habitats and occur in the southern Baltic Sea only during winter and migration. The different species are not evenly distributed, but show clear preferences for certain areas and habitats, depending on their diet and foraging strategies. Birds feeding on or near the sea bottom, like sea ducks and grebes, are restricted to areas with low water depth and, according to the substrate preference of their main prey species, occur in waters over specific bottom sediment types. Species that mainly forage on pelagic fishes, like auks, are not restricted to shallow waters but also occur in deeper offshore areas. Surface feeding species are mainly represented by gulls. Especially the large Larus-species have strongly adapted to the use of discards and offal from fishing vessels and distribution patterns are influenced by the occurrence of human fishing activities accordingly. Detailed ecological questions are addressed in two case studies on grebes that are represented in the study area by three species and more than 10 000 wintering birds. The habitat choice of Slavonian Grebes is influenced by water depth and bottom sediment type: they prefer shallow waters of 4 to 14 m depth and occur only over sandy sediments. Both habitat factors can be linked to diet preferences: while the diving depth of endothermic animals is limited due to energetic constraints and thermoregulation, sediment type is regarded to be a proxy for food choice. The diet of Slavonian Grebes mainly consists of gobies that frequently occur over sandy bottom substrates. Great Crested and Red-necked Grebes prefer waters up to 26 m and 30 m, respectively. Within the areas suitable with regard to water depth, the three grebe species exhibit distinctive distribution patterns with only low spatial overlap. Furthermore, with increasing abundance of one grebe species, the abundance of the others significantly decreases. As the diet of the three grebe species differs only slightly, they seem to enable coexistence by spatial segregation rather than by ecological separation via different dietary niches. This indicates that interspecific competition, well known to influence seabird communities during the breeding season, can also act as structuring mechanism in densely populated wintering areas. The most prominent threat to the highly abundant diving bird species are set net fisheries, extensively carried out in the southern Baltic Sea and leading to the entanglement and drowning of birds foraging underwater. Two indices are developed to overcome the lack of comprehensive knowledge on bird bycatch: a spatial overlap approach indicates the potential of conflict for diving birds in relation to set net fisheries, based on data of bird abundance and fishing activities, while a vulnerability index based on relative bird abundance indicates the maximum susceptibility of birds towards drowning mortality. Vulnerability and potential conflict exhibit spatial and temporal variations and are particularly high in coastal areas and on shallow offshore grounds during winter and spring. Large areas of the German Baltic Sea have been designated as protected areas and the implementation of management objectives is currently under process. The presented approach involving an improved understanding of the spatio-temporal occurrence of potential bycatch events and the assessment of bird vulnerability towards the impact provides a valuable tool for such management purposes. By addressing various aspects of the ecology of birds at sea, this thesis fills considerable gaps in the knowledge about one of the most important areas for seabirds and waterbirds in the Western Palaearctic. It provides basic information on the relationship between birds and their biological and physical environment, which is fundamental to evaluate the consequences of human impacts and to set up appropriate conservation measures

Insulin-like growth factor-1 in CNS and cerebrovascular aging

Insulin-like growth factor-1 (IGF-1) is an important anabolic hormone that decreases with age. In the past two decades, extensive research has determined that the reduction in IGF-1 is an important component of the age-related decline in cognitive function in multiple species including humans. Deficiency in circulating IGF-1 results in impairment in processing speed and deficiencies in both spatial and working memory. Replacement of IGF-1 or factors that increase IGF-1 to old animals and humans reverses many of these cognitive deficits. Despite the overwhelming evidence for IGF-1 as an important neurotrophic agent, the specific mechanisms through which IGF-1 acts have remained elusive. Recent evidence indicates that IGF-1 is both produced by and has important actions on the cerebrovasculature as well as neurons and glia. Nevertheless, the specific regulation and actions of brain- and vascular-derived IGF-1 is poorly understood. The diverse effects of IGF-1 discovered thus far reveal a complex endocrine and paracrine system essential for integrating many of the functions necessary for brain health. Identification of the mechanisms of IGF-1 actions will undoubtedly provide critical insight into regulation of brain function in general and the causes of cognitive decline with age

Insulin-like growth factor 1 deficiency exacerbates hypertension-induced cerebral microhemorrhages in mice, mimicking the aging phenotype

LBL

A genome-wide library of MADM mice for single-cell genetic mosaic analysis

Mosaic analysis with double markers (MADM) offers one approach to visualize and concomitantly manipulate genetically defined cells in mice with single-cell resolution. MADM applications include the analysis of lineage, single-cell morphology and physiology, genomic imprinting phenotypes, and dissection of cell-autonomous gene functions in vivo in health and disease. Yet, MADM can only be applied to 96% of the entire mouse genome can now be subjected to single-cell genetic mosaic analysis. Beyond a proof of principle, we apply our MADM library to systematically trace sister chromatid segregation in distinct mitotic cell lineages. We find striking chromosome-specific biases in segregation patterns, reflecting a putative mechanism for the asymmetric segregation of genetic determinants in somatic stem cell division

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

The Crowdsourced Replication Initiative: Investigating Immigration and Social Policy Preferences. Executive Report.

In an era of mass migration, social scientists, populist parties and social movements raise concerns over the future of immigration-destination societies. What impacts does this have on policy and social solidarity? Comparative cross-national research, relying mostly on secondary data, has findings in different directions. There is a threat of selective model reporting and lack of replicability. The heterogeneity of countries obscures attempts to clearly define data-generating models. P-hacking and HARKing lurk among standard research practices in this area.This project employs crowdsourcing to address these issues. It draws on replication, deliberation, meta-analysis and harnessing the power of many minds at once. The Crowdsourced Replication Initiative carries two main goals, (a) to better investigate the linkage between immigration and social policy preferences across countries, and (b) to develop crowdsourcing as a social science method. The Executive Report provides short reviews of the area of social policy preferences and immigration, and the methods and impetus behind crowdsourcing plus a description of the entire project. Three main areas of findings will appear in three papers, that are registered as PAPs or in process