Ecomorphology: Predator induced shell modification in a fresh water snail
The New Zealand Mud Snail Potamopyrgus antipodarum is morphologically highly variable with respect to shell shape, size and armature. Regarding the latter, shells can be smooth or bear a row of spines. It has been suggested that spines may develop as defense against predators. However, experimental evidence is ambiguous suggesting that spines can only develop with the “right genetic background”. Using marble crayfish as predators, the candidate shall investigate whether spines can predictably be induced in samples from morphologically different populations of P. antipodarum.
Taxonomy: Description of new species of spring and groundwater snails
Taxonomic descriptions of new species are ideally based on several lines of evidence. We are routinely using morphological and genetic data to describe species of spring and groundwater snails of the families Hydrobiidae and Tateidae. The spectrum of methods comprises morphometrics, dissection, scanning electron microscopy, µCT, and DNA sequencing for phylogenetic analyses.
Phylogenetics: Reconstructing time calibrated trees in the framework of coalescence theory
Recent theoretical considerations and simulations suggest that phylogenetic reconstructions of multigene data are more accurate if conducted in the framework of coalescence theory rather than based on concatenated sequences. In this project, a pubished analysis of concatenated sequences shall be compared to a new analysis conducted in the recently available package BEAST 2 implementing the multispecies coalescent.
Recent bachelor theses
Completed bachelor theses
- Sandra Mänty (LaEco): Temporal variation of the behaviour of female Black-headed gulls (Chroicocephalus ridibundus) at the breeding area (finished January 2021)
- Yannick Rathgeber (LaEco): Influence of scrub encroachment on the breeding bird community in the region Dornbusch on Hiddensee island (finished October 2020)
- Thomas Hempelmann (LaEco): Variation of behaviour of male Black-headed gulls (Chroicocephalus ridibundus) at the nesting site (finished August 2020)
- Hannah Pump (LaEco): Differences concerning the dietary composition of Black-headed gulls (Chroicocephalus ridibundus) between two big breeding colonies in Mecklenburg-Western Pomerania (finished August 2020)
- Lena Schlünß (LaEco): Breeding bird population of the Strandwallfächer on Hiddensee island (finished January 2020)
- Max Richter (LaEco): Predation of clutches of Northern Lapwing (Vanellus vanellus) in North Rhine-Westphalia (finished December 2019)
- Anne Cramaro (LaEco): Analysis of population dynamics of the little owl Athene noctua depending on the habitat structure in North Rhine-Westphalia (finished November 2019)
- Jannis Dimmlich (LaEco): Survey of breeding success of Common Ringed Plovers (Charadrius hiaticula) with and without methods to protect clutches on Föhr, an island in the North Sea (finished October 2019)
- Lukas Barbek (Biology): Analysis of the behavior of Common cranes after hatching of the chicks using camera traps (finished March 2019)
- Stan Patzig (Biology): About the anatomy and systematic position of New Caledonian fresh water snails (finished March 2019)
- Raphael Woll: A distance sampling survey of breeding birds in Azerbaijan (finished February 2019)
- Jacob Fröhlich(Biology): Breeding behaviour of Chroicocephalus ridibundus in two different colonies (finished June 2018)
- Marcel Tenhaeff (Biology): Determination of age and sex in Bohemian waxwing (Bombycilla garrulus (L. 1758)). (finished March 2018)
- Jonas Kotlarz (LaEco): Development of breeding bird communities in rewetted Polder at the Peenetal (finished January 2018)
- Simon Piro(Biology): Philopatry within a colony of black-headed gulls (Larus ridibundus) (finished November 2017)
- Narges Lieker (LaEco): Analysis of phenotypic plasticity of the shell of the freshwater mudsnail Potamopyrgus antipodarum (finished October 2017)
- Josafat Burmeister (Biology): Analysis of the attention and the defense behaviour of breeding pairs of Common cranes (Grus grus) depending on the habitat structure (finished 2017)
- Isabel Barwisch (Biology): Analysis of breeding behaviour of the Common cranes (Grus grus) in Mecklenburg-Western Pomerania based on pictures of nest cameras (finished January 2017)
- Andy Beggerow (Biology): On the colour perception of the snail shell of Capea by birds (finished January 2017)
- Julia Eberspach (Biology): Variation in Abundance and Diversity of Humminbirds on Changes of Environmental Factors in Manizales, Colombia (finished January 2017)
- Jessica Kolbe (Biology): Interfering influences on breeding behaviour of the Common cranes (Grus grus) in northern Germany (finished January 2017)
- Laura-Marie Sandow (Biology): Recording of breeding temperature in nests of Common Cranes (Grus grus) by using data loggers (finished January 2017)
- Paul-August Schult (LaEco): Spatial distribution of breeding black-headed gulls (Chroicocephalus ridibundus) in the natural reserve "Insel Böhmke und Werder" over the course of the year (finished January 2016)
- Christian Behnke (Biology): Untersuchungen zum Schalenpolymorphismus der Schnirkelschnecken Capea hortensis und Capea nemoralis in Allopatrie und Sympatrie (finished February 2013)
Recent master theses
Completed master theses
- Antje Kieburg (Biodiversity and Ecology): Chick rearing in the Common Crane (Grus grus) in Mecklenburg-Western Pomerania (finished March 2021)
- Hannes Luck (Landscape Ecology): Adult survival rates of Central Siberian passerines (finished March 2021)
- Annemarie Kurth (Biodiversity and Ecology): Do management activities have an effect on the food availability for chicks of the Eurasian Curlew (Numenius arquata) on the Borken (MV)? (finished February 2021)
- Simon Piro (Biodiversity and Ecology): Revealing different migration routes in Baltic Common Terns (Sterna hirundo) with light-level geolocators (finished January 2021)
- Annika Kühnl (Biodiversity and Ecology): Optimal clutch size? - Effects of an additional egg on the incubation behaviour of Common cranes (Grus grus) (finished August 2020)
- Pia Fetting (Landscape Ecology): A comparison between standardised mist-netting and bioacoustic monitoring of migratory birds at Besh Barmag bottleneck in Azerbaijan (finished June 2020)
- Tewannakit Mermagen (Landscape Ecology): Differences in sexual investment of breeding Black-headed Gulls (Chroicocephalus ridibundus) on the island of Böhmke (finished October 2019)
- Wilderich Stein (Biodiversity and Ecology): Food spectrum of not yet fully fledged Black Terns (Chlidonias niger) (finished September 2019)
- Sören Kaack (Biodiversity and Ecology): Home range analysis of breeding Black-headed Gulls (Chroicocephalus ridibundus) in Mecklenburg-Western Pomerania (finished July 2019)
- Kai von Jungmeister (Biodiversity and Ecology: Reproduction and growth in the invasive freshwater snail Potamopyrgus antipodarum (finished June 2019)
- Max Baumgarten (Landscape Ecology): Breeding Bird Communities in Azerbaijan's West and their response to Land use (finished March 2019)
- Benjamin Weigelt (Landscape Ecology): Foraging behavior of male Lesser Spotted Eagles (Clanga pomarina) during the breeding season considering possible protective measures for the conservation of the species (finished January 2019)
- Annemarie Luise Kühn (Biomathematics): A tool for an automated identification of diagnostic molecular characters for the delineation of taxa (finished December 2018)
- Isabel Barwisch (Biodiversity and Ecology): Sexual differential investment and influence of disturbances on reproductive success of common cranes (Grus grus) (finished September 2018)
- Christoph Himmel (Landscape Ecology): Research on wader in Southern Azerbaijan, one of the last under-surveyed areas of the Western Palearctic (finished August 2018)
- Janina Pankratz (Biodiversity and Ecology): Development of breeding bird communities in rewetted Polder at the Peenetal: Comparison of two habitat types (finished June 2018)
- Corinna Langebrake (Biodiversity and Ecology): Genetic studie of Bohemian waxwings (Bombycilla garrulus) regarding the familly structure in the flock (finished May 2018)
- Esther Lutz(Landscape Ecology): The Impact of Nest Predation and Disturbance an Common Ringed Plovers (Charadrius hiaticula) on the Wadden Sea Island of Föhr. (finished March 2018)
- Philipp Rau (Biodiversity and Ecology):Analysis of brood temperature of Common cranes (Grus grus): Cases and fluctuations (finished March 2018)
- Mariann Jurke (Biodiversity and Ecology):Diet composition and foraging habits of breeding Black-headed Gulls, Chroicocephalus ridibundus, in Mecklenburg-Western Pomerania (finished February 2018)
- Judith Brückner (Biodiversity and Ecology):Nest-monitoring: Using wildlife cameras on a colony of Black-headed Gulls (Chroicocephalus ridibundus) (finished December 2017)
- Manzar Rezaee(Landscape Ecology): Intraspecific structural variation of the eggshells in a population of Black-headed gull (Chroicocephalus ridibundus) (finished September 2017)
- Anna Maria Eisen (Mathematics and informatics): Statistic analysis of partial migration of kestrels (Falco tinnunculus) using ringing data (finished August 2016)
- Marina Ide (Biodiversity and Ecology): Ultraviolet plumage reflectance of two sibling bird species (Passeriformes): differences between human and avian color perception (finished April 2016)
- Janine Dombrowski: Evolution of plumage colors in passerines - using a phylogenetic approach (finished March 2015)
- Marlen Becker: Incipent speciation or holey species boundaries between a pair of freshwater gastropod species from New Caledonia? (finished December 2014)
- Andre Böckers: Conflict in phylogenetic signal between mitochondrial and nuclear DNA in the landsnail genus Theba (finished December 2014)
- Lars Sund (Biodiversity and Ecology): Identification of individual Water rail (Rallus aquaticus) females on the basis of color patterns of their eggs (finished August 2014)
Completed diploma theses
- Janine Weigelt (LaE): Habitat analysis and breeding success of whinchat (Saxicola rubetra) in ecological ökologisch cultivated grassland and clover grass in the Gnoien area (Mecklenburg-Western Pommerania). (finished november 2014)
- Cathleen Krämer: Should I stay or should I go...? Partial migrationof the buzzard Buteo buteo. (finished may 2014)
- Helgard Frigga Lemke(LaE): Untersuchungen zum Bruterfolg der letzten 15 Jahre des Alpenseglers Tachymarpis melba mit Hilfe von Geolokatoren im Raum Baden (Aargau, Schweiz). (finished february 2014)
- Florian Iser (LaE): Der Einfluss von 18 Jahren Verbuschung auf die Avifauna der Insel Hiddensee: Eine vergleichende Brutvogelkartierung am Dornbusch auf Hiddensee. (finished october 2013)
- Eduardo Salinas-Lange (Biology): Untersuchungen zu Habitatseffekten auf die Farbvariationen der Eier des europäischen Kranichs Grus grus im Raum Parchim. (finished july 2013)
- Daniel Holte (LaE): Who stays, who goes? Partial migration in East German Common Kestrels (Untersuchungen zu Migrationstrategien des Turmfalken Falco tinnunculus in Ostdeutschland mit Hilfe von Beringungsdaten der letzten 30 Jahre. (finished june 2013)
- Elisabeth Franke (LaE): Habitatanalyse des Zwergsumpfhuhns Porzana pusilla im Djoudj Nationalpark - NW Senegal. (finished may 2013)
- Martin Schuck (Göttingen): Habitatuntersuchungen zum Zwergsumpfhuhn Porzana pusilla in der Coto de Doñana - Spanien. (finished 2012)
- Steffen Koschkar (Ecology, Uni-Gießen): Ernährung und Nahrungsspektrum des Zwergsumpfhuhns Porzana pusilla im Senegaldelta – NW Senegal. (finished october 2010)
- Carolin Däumer (Biomathematics): Phylogeographische Rekonstruktion der Ausbreitung von der Mittelmeersandschnecke Theba pisana (Gastropoda/Pulmonata/Helicidae) anhand molekularer Daten. (finished august 2010)
- Julia Daebeler (LaE): Habitatanalyse der Wasserralle (Rallus aquaticus) in einem wiedervernässten Polder des oberen Peenetals. (finished june 2010)
- Johanna Haß & Sebastian Matuszewski (Biomathematics): Diversität von Influenza A Subtyp H1N1. (finished june 2010)
- Susan Zielske (Biology):Radiation und Ursprung der Hydrobiidae (Rissooidea: Caenogastropoda: Gastropoda) in den alten Seen Poso und Towuti auf Sulawesi/Indonesien. (finished february 2010)
- Anna-Luise Vogel (Biology): Genetische Bestimmung der Herkunft von im Senegal überwinternden Seggenrohrsängern Acrocephalus aquaticus. (finished september 2009)
All seven species of rail occur on the restored and re-wetted areas in the valley of the river Peene. This includes the three species of Porzana, P. porzana, P. parva and P. pusilla. The latter was thought to be extinct in Germany. We are interested in the habitat requirements of these three species during the breeding season in order to understand how these closely related species can co-exist. We investigate abiotic and biotic characteristics of habitats as well as spatial and temporal use of territories, intra- and interspecific territorial behavior, and social interactions. In this context, we have an additional focus on the more common Water Rail, which probably also interacts with the Porzana species. These investigations are also complemented by molecular approaches in order to answer population genetic and demographic questions. The ultimate goal is the elaboration of conservation and management measures aiming at the permanent establishment of these rail populations.
Scientists involved: Dipl. Biol. Alexander Eilers, Dr. Angela Schmitz, Dipl. Biol. Benjamin Herold, Dr. Martin Haase
Financing:http://www.brehm-fonds.de/de/projekte/heimliche-bewohner-des-rohrdschungels-rallen/Brehm Fonds für den internationalen Vogelschutz, Bonn
An individual of the colonial breeding Black-headed Gull (Larus ridibundus) produces per season only a few offsprin with long parental care. It requires great energy input. In such colonies it has been found thet intraspecific brood parasitism occur naturally in almost a quarter of the cases. Each female lays eggs, that are different in colour and spottiness. The aim of the study is to investigate, if they may have developed mechanisms for recognizing their own eggs, like an individual colour "fingerprint".
Scientists involved: M.Sc. Katja Rahn, Dr. Angela Schmitz-Ornés
Since the end of the 19th century continuously positive population developments of the Common cranes (Grus grus) have been observed over the European continent, despite intensive agricultural and silvicultural usage (Leito et al. 2003; Boldt 2015). Besides the increasing total numbers of individuals, the distribution range of Common cranes is also growing, showing recent expansions towards Western and Southern Germany and Europe, respectively (Lehrmann 2018). However, recent studies suggest a decreased reproductive success within several areas of high population densities, like in the German federal states Mecklenburg-Western Pomerania and Brandenburg (Mewes 2014). Density-dependent decreases of reproductive success have been documented for other bird species, like Mute swans (Cygnus olor) and Barnacle geese (Branta leucopsis), already (Nummi & Saari 2003; Larsson & Forslund 1994). High population densities intensify competition for territories, good nesting sites and food sources (Fernandez et al. 1998). Whereas only 8 % of the population in Mecklenburg-Western Pomerania and Brandenburg nested within agricultural landscapes, accounted as suboptimal habitats, in 1996, this proportion increased to more than 30 % in 2010 and rising (Mewes 2010). Which factors really are affecting the reproductive success of Common cranes?
The main objectives of this research project are the analysis of the current demographic situation of the European population of Common cranes and to identify factors affecting survival and reproductive success along their geographical range.
Effects of different landscape features or population densities will not only be analyzed from an ecological and behavioural perspective, but also from an physiological perspective by analyzing stress hormones. Individuals breeding within areas of high population densities might suffer from higher stress levels due to intraspecific competition and a lack of suitable nesting habitats and feeding grounds. Since more experienced individuals might be more successful at coping with stressful situations, age could also have an effect.
This study aims at establishing a general basis for future research on cranes and results shall be available for deriving conservation implications and management efforts.
Scientists involved: M.Sc. Isabel Barwisch, Dr. Angela Schmitz Ornés
Due to anthropogenic influence, more and more environmental changes are having a great impact on the Earth and on the organisms living on it. Generally, there are three options how organisms can react to environmental changes in their habitat: extinction, migration and adaptation. If they are unable to disperse or to adapt, their risk of extinction is increasing. Others are highly adaptable and easily cope with new and changing environments. Invasive species, for example, are colonizing new habitats with few individuals and are supposed to suffer from reductions in their genetic diversity due to the founder effect. Nevertheless, various invasive species, as the New Zealand mud snail, Potamopyrgus antipodarum, are able to cope well with different environmental conditions and stress and reproduce successfully. Moreover, some of these organisms show traits that are highly variable in different environments. Even within one genotype one can observe different phenotypes under different or changing environmental circumstances (phenotypic plasticity). The shells of P. antipodarum show a high, habitat-depending variability and the shell morphology is adaptive and genetically as well as phenotypically highly plastic. In its native habitat New Zealand, it reproduces diploid-sexually or polyploidy-asexually via parthenogenesis. In invaded regions, such as Australia, Japan, Chile, USA and many European countries, only polyploid, hence asexually reproducing lineages are found.
We aim to disentangle genetic and environmental effects in both common garden and transplant experiments. In common garden experiments, we will estimate heritability of the variability of the shell morphology of P. antipodarum using geometric morphometrics.Using reciprocal transplant experiments, we want toexamine reactions of the snails to changing habitats under most natural conditions possible. Since phenotypic plasticity is apparently very important for P. antipodarum to colonize various types of habitats, we furthermore plan to analyse genome-wide methylation patterns from native and invasive individuals of different habitats using the Nanopore technology in collaboration with Bernhard Misof and Lars Podsiadlowski (Bonn) and relate the methylation patterns to habitat and climate variables as well as shell morphology. In order to identify genes, we will map our data against the genome of P. antipodarum, which is currently being annotated by our project partner Maurine Neiman (Iowa).
Scientists involved: M.Sc. Lisa Männer, Dr. Martin Haase
A secret of success: Phenotypic plasticity as prerequisite for being a generalist
State of the art: During phases of global change generalist species are predicted to have a higher survival chance than specialists. However, what constitutes a generalist, in particular with regard to the relative importance of phenotypic plasticity and genetic adaptation, is little understood. This question will be addressed here in the ovoviviparous New Zealand mud snail Potamopyrgus antipodarum occupying a wide range of fresh and brackish water habitats and exhibiting an extreme morphological variation. In this species, triploid, (almost) all-female parthenogenetic lineages have evolved repeatedly and successfully invaded other continents, emphasizing the species’ adaptive potential. The broad ecological niche has possibly been realized due to a high degree of phenotypic plasticity. Gastropod shell shape and size have been already related to environmental factors including current velocity and temperature. Therefore, this project focuses on the adaptive value of shell shape and size as well as on osmotolerance in P. antipodarum, disentangling phenotypic and genetic adaptation and the influence of the reproductive mode thereon.
Working hypotheses and work plan: We will relate adult shell size and shape of P. antipodarum, which has finite growth, as well as the number of brooded embryos to habitat characteristics in its native range. We will control for confounding factors including phylogeny, geography, ploidy, parasitism, predation risk, and population density. In a similar fashion, we will analyze parthenogenetic populations established in Europe assuming that clonal strains accumulate mutations and thus adapt differentially. These analyses will form the basis for the selection of differentially adapted populations for common garden experiments aiming at measuring reaction norms, estimating heritabilities through parent-offspring regressions, thus disentangling genetic from plastic effects. Snails will be exposed to different flow velocities, temperatures, and salinities and effects on shell size, shape, growth rate, fecundity and survival will be recorded. We expect sexual populations to show a higher degree of plasticity, and, assuming costs of phenotypic plasticity, trade-offs with fecundity.
Thesis topic: Variable shell morphology as key for colonizing a wide spectrum of habitats?
Scientists involved: Gerlien Verhaegen, Martin Haase
Financing:Graduiertenkolleg RTG 2010 (Project A1)
The phenomenon of migration is documented for many bird species all over the world. Since bird ringing was initiated at the end of the 19th century, migratory strategies have become an important area of research. However, even for single Central European species some strategies, such as ‘partial migration’, are still little understood. In this project, migratory strategies of five German raptor species, which are known to be partial migrants (Common Kestrel Falco tinnunculus, Peregrine Falcon Falco peregrinus, Common Buzzard Buteo buteo, Eurasian Sparrowhawk Accipiter nisus and Northern Goshawk Accipiter gentilis), are investigated by means of ring-recovery data. Differences between sex and age classes are analysed as well as possible regional differences. The distinction between natal dispersal and migration of juveniles in ring-recovery data as well as influences of weather on migratory strategies are also part of this study.
During a field trip through Azerbaijan in autumn 2007 an unknown bird migration bottleneck was discovered between the Greater Caucasus and the Caspian Sea. Both are known topographical barriers and at Mount Besh Barmag migrating birds are funnelled through a 2.5 km wide coastal plain. At this location, a short study in October 2007 produced high numbers of migrating birds, but information about migration intensity in the rest of the year remained unclear. Therefore, two more field trips in autumn 2011 and spring 2012 have been undertaken to cover the main migration periods. Daily visual observations from three different points covered raptor, passerine and waterbird migration. Furthermore, an automated sound recording system was used to acoustically investigate bird migration.
Scientists involved: Dipl. Laök. Michael Heiss
Across the South Pacific islands, rissooidean freshwater gastropods have a peculiar distribution occurring almost exclusively on archipelagos with parts that are at least 10 Mio years old. This suggests that the entire radiation is among the oldest among animals in the region. Anatomical investigations indicated that these snails from New Zealand, New Caledonia, Vanuatu, Fiji and the Austral Islands form a monophyletic group. The only marine/brackish water relatives occur in New Zealand, where these snails were shown to have colonized freshwater three times independently. Based on these facts and findings, it has been hypothesized that the entire Pacific radiation had its origin in New Zealand from where the snails dispersed to the other archipelagos. In this group of snails, phylogenetic relationships can only be inferred from DNA sequence data. Establishing a robust phylogeny including also (possibly) related species from Australia we will test the outlined hypothesis against alternative scenarios, analyze speciation patterns on three levels (intra-island, within archipelagos, across archipelagos), assess the potential impact of extinction on our conclusions, analyze diversity patterns, and put the resulting big picture into a comparative context of general South Pacific biogeography.
Scientists involved: Dr. Martin Haase, Dr. Susan Zielske
Das Zwergsumpfhuhn Porzana pusilla gilt als einer der am wenigsten erforschten Brutvögel Mitteleuropas. Als Langstreckenzieher verbringt die Art wenigstens die Hälfte des Jahres auf dem Zug und im Winterquartier. Über die Lage potentieller Überwinterungsgebiete im subsaharischen Afrika konnte bislang aufgrund der sporadischen Nachweise nur gemutmaßt werden. Im Rahmen einer Expedition des BirdLife International Aquatic Warbler Conservation Teams AWCT wurde im Frühjahr 2007 im “Parc National des Oiseaux du Djoudj” am unteren Senegal jedoch eine bemerkenswert große Zahl an Zwergsumpfhühnern festgestellt.
Sowohl Seggenrohrsänger als auch Zwergsumpfhuhn besiedeln dort dasselbe Habitat: großflächige, im Verlaufe des Winters allmählich austrocknende Grassümpfe, die zudem einer Vielzahl anderer, z. T. stark bedrohter Zugvogelarten Winterquartier bieten. Die herausragende Bedeutung dieses Lebensraums war bisher vom internationalen Naturschutz vollkommen übersehen worden. Trotz der Einrichtung geschützter Flächen (Djoudj‐Nationalpark/Senegal, Diawling Nationalpark in Mauretanien), liegen Teile der potentiellen Lebensräume im Senegaldelta außerhalb dieser Schutzzonen. Für einen nachhaltigen Schutz des Zwergsumpfhuhns und seiner Überwinterungsgebiete ist es demnach unerlässlich, Kenntnis über die ökologischen Faktoren zu erlangen, die das Überleben dieser Art gewährleisten. Hierzu soll zunächst der Status der im Djoudj-Gebiet vorkommenden Population untersucht werden: Handelt es sich ausschliesslich um paläarktische Zugvögel, die einer oder mehreren europäischen Brutpopulationen zugeordnet werden können? Oder umfasst das Vorkommen hauptsächlich afrikanische Brutvögel, die das Gebiet nach dem Austrocknen der Sümpfe wieder Richtung Süden verlässt?
Desweiteren soll die räumliche und saisonale Habitatnutzung des Zwergsumpfhuhns im Nationalpark und auf angrenzenden Flächen ermittelt und relevante biotische und abiotische Standorteigenschaften und Habitatstrukturen einschließlich der heutigen und früheren Nutzung identifiziert werden. Weiteres Ziel ist, die Gefährdungssituation der genutzten Flächen zu untersuchen, um schliesslich Monitoringparameter und Management-Empfehlungen ableiten und Schutzkonzepte für bisher ungeschützte Flächen erarbeiten zu können.
Mitarbeiter:Dr. Nina Seifert, Dr. Angela Schmitz, Dr. Martin Haase
Finanzierung: Stresemann-Förderung der Deutschen Ornithologen Gesellschaft, Begabtenförderung des Evangelischen Studienwerks Villigst e.V.
Reproducing the Abstract of “New life in old mires – breeding birds in rewetted valley fen mires”, the book resulting from Benjamin Herold’s Dissertation project [B. Herold 2012, Neues Leben in alten Mooren – Brutvögel wiedervernässter Flusstalmoore. Bristol-Stiftung (Zürich), Verlag Haupt, Bern.]
Valley fen mires (VFM) are a characteristic feature of northeast Germany. Besides serving important landscape-ecological functions such as accumulation of greenhouse gases and water retention, they used to contain a highly specialized avifauna. Within the last 70 years, most VFMs have been heavily damaged due to intensified land use and heavy drainage, leading to the disappearance of a number of characteristic bird species. Some of them are faced with global extinction today. In the federal state of Mecklenburg-Western Pomerania, large areas of VFMs have been rewetted in a number of restoration projects within the last 15 years. This study targets the following questions:
- What impact does rewetting have on breeding birds, considering vegetation succession, water levels and habitat selection?
- What are the general conditions for the return of endangered or characteristic species?
- What can be done to support them?
To answer these questions, an analysis was carried out using data on breeding birds, vegetation and water level conditions from 21 rewetted VFMs covering a total of 2167 ha. 21 indicator species of pristine VFMs were used to evaluate the outcome. The main results are:
- Rewetted VFMs comprise bird communities of high diversity and conservation value.
- Indicator species such as Garganey (Anas querquedula), Spotted Crake (Porzana porzana) and Sedge Warbler (Acrocephalus schoenobaenus) recolonize even after a short time.
- Most indicator species require sedges and water levels above the ground.
- Sites with high inundation levels support highly endangered species of shallow lakes: Little Bittern (Ixobrychus minutus) and Great Bittern (Botaurus stellaris), Little Crake (Porzana parva) and Black Tern (Chlidonias niger).
It is concluded that permanently raising the water table to slightly above ground level is the key factor for most endangered species. This also ensures the development of suitable vegetation in the long term and provides the possibility for a real sustainable land use. A “wet land use” will also support the missing indicator species, which require a large area of low vegetation which is not available under the current eutrophic conditions.
Scientists involved:Dr. Benjamin Herold, Dr. Angela Schmitz
Based on morphological characters it has been impossible to analyze the phylogenetic relationships of the extremely speciose superfamily Sylvioidea due to convergence affecting the evolution of several important character systems. DNA-DNA hybridization and early attempts of DNA sequencing have laid new foundations for understanding relationships and evolution within this large group of fairly uniform passerines. However, many questions remained open due to limited taxon sampling. In her dissertation, Silke Fregin sequenced seven genes (c. 6.3 kbp) of a total of 79 species representing all recognized families and taxa of uncertain affinity. Although a number of relationships among families remained poorly supported, this so far most comprehensive analysis clarified several open questions. Three new families, Erythrocercidae, Macrosphenidae and Scotocercidae, were introduced and another three, Paridae, Remizidae, and Stenostiridae, excluded from Sylvioidea. Further analyses were dedicated to the family Acrocephalidae comprising the probably most indistinct species. These resulted in a refined taxonomy and highlighted pitfalls in comparisons of genetic distances as applied e.g. in barcoding.
Scientists involved:Dr. Silke Fregin, Dr. Martin Haase; Dr. Per Alström (Uppsala), Dr. Urban Olson (Göteborg)