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Bergenhusen, Germany

Rosner S.,University of Marburg | Cimiotti D.V.,University of Marburg | Cimiotti D.V.,Michael Otto Institute im NABU | Brandl R.,University of Marburg
Journal of Ornithology | Year: 2014

Recently, based on genetic analysis, a distinct lineage of the Northern Raven has been described and assigned to the subspecies Corvus corax tingitanus on the Canary Islands. However, all sampled birds originated from only one island of the archipelago (Fuerteventura). We revisited the issues of ravens on the Canary Islands and collected additional samples from other Canarian Islands as well as from other populations in Northern Africa and Europe. Using mitochondrial DNA (control region, cytb), our samples confirmed the occurrence of a distinct lineage on two eastern islands of the archipelago. However, on other islands, we found specimens that did not belong to the Canarian lineage but were closely related to birds from Africa, Europe and the Mediterranean islands. We found that on at least one of these islands the Canarian and the Holarctic lineages coexist. The distribution patterns of the genetically distinct Canarian lineage match the subspecies C. c. jordansi, which was previously described by morphological characters such as small size and brownish feathers. We suggest that the distinct mtDNA lineage (C. c. tingitanus) and the morphologically described subspecies C. c. jordansi from the Eastern Canary Islands refer to the same population and recommend dropping the name C. c. tingitanus. © 2013 Dt. Ornithologen-Gesellschaft e.V. Source


Kupper C.,Harvard University | Kupper C.,University of Sheffield | Edwards S.V.,Harvard University | Kosztolanyi A.,Eotvos Lorand University | And 11 more authors.
Molecular Ecology | Year: 2012

Gene flow promotes genetic homogeneity of species in time and space. Gene flow can be modulated by sex-biased dispersal that links population genetics to mating systems. We investigated the phylogeography of the widely distributed Kentish plover Charadrius alexandrinus. This small shorebird has a large breeding range spanning from Western Europe to Japan and exhibits an unusually flexible mating system with high female breeding dispersal. We analysed genetic structure and gene flow using a 427-bp fragment of the mitochondrial (mtDNA) control region, 21 autosomal microsatellite markers and a Z microsatellite marker in 397 unrelated individuals from 21 locations. We found no structure or isolation-by-distance over the continental range. However, island populations had low genetic diversity and were moderately differentiated from mainland locations. Genetic differentiation based on autosomal markers was positively correlated with distance between mainland and each island. Comparisons of uniparentally and biparentally inherited markers were consistent with female-biased gene flow. Maternally inherited mtDNA was less structured, whereas the Z-chromosomal marker was more structured than autosomal microsatellites. Adult males were more related than females within genetic clusters. Taken together, our results suggest a prominent role for polyandrous females in maintaining genetic homogeneity across large geographic distances. © 2012 Blackwell Publishing Ltd. Source


Schrautzer J.,University of Kiel | Fichtner A.,University of Kiel | Huckauf A.,University of Kiel | Rasran L.,Michael Otto Institute im NABU | Jensen K.,University of Hamburg
Flora: Morphology, Distribution, Functional Ecology of Plants | Year: 2011

The orchid Dactylorhiza incarnata (L.) Soó is a highly polymorphic species listed as endangered in many regional red lists of Central Europe and Scandinavia. The dramatic decline of its populations during recent decades has been caused by the loss and degradation of their natural and semi-natural habitats (fens and wet meadows, respectively) as a result of secondary succession following intensification or abandonment of traditional land use.In this study, we analysed the effects of abandonment and re-introduction of mowing on the long-term (28 years) population dynamics of Dactylorhiza incarnata at Lake Barsbek in northern Germany. In this area, to preserve a remaining population of D. incarnata, an annual mowing regime was re-established in 1981 on site M-1 of the investigated plots after a period of abandonment. Annual mowing was introduced on a second site, M-2, in 1987. Two- to three-year mowing was introduced on a third site, M-3. Site A, abandoned since 1970, was used as a reference. On each of these sites, flowering individuals were counted once a year. Population structure and accompanying vegetation were recorded simultaneously. In 2006, light measurements were carried out in the mowed areas.The D. incarnata population at M-1 increased exponentially during the first 10 years after re-introduction of mowing. Pronounced decreases in the number of flowering individuals were recorded in 1997 and 2003. Population dynamics at M-2 generally resembled the temporal development at M-1. D. incarnata disappeared on site A during the investigation period, while vegetation height and litter layer increased by 60 and 100%, respectively. D. incarnata was able to withstand reduced light availability to a certain extent by increasing its vertical growth (shade avoidance). It is concluded that the maintenance of D. incarnata populations in Central Europe requires continuation or re-establishment of wet meadow management. On previously abandoned sites, an initially higher mowing frequency is recommended. Management intensity can be reduced after phytomass production of the vegetation has declined. © 2011 Elsevier GmbH. Source


Roodbergen M.,Wageningen University | Roodbergen M.,University of Groningen | van der Werf B.,Wageningen University | Hotker H.,Michael Otto Institute im NABU
Journal of Ornithology | Year: 2012

In this review, we summarize available data on nest success, chick survival and reproductive output, and adult and juvenile survival of five meadow breeding waders in Europe: Eurasian Oystercatcher (Haematopus ostralegus), Northern Lapwing (Vanellus vanellus), Black-tailed Godwit (Limosa limosa), Eurasian Curlew (Numenius arquata), and Common Redshank (Tringa totanus). The survival data from the assembled studies did not show an overall decline in adult survival in any of these species. However, our meta-analyses on reproduction data show that chick survival declined strongly in the last 40 years in western Europe and that nest success declined in eastern Europe in the period 1995-2005, in Scandinavia in the period 1985-2005, and in western Europe in the period 1950-1980. Predation of nests has increased by c. +40% in all five species in western Europe during the last four decades. Results on reproductive output, the number of fledglings produced per breeding pair, were less clear. A decline was apparent in Eurasian Oystercatcher in the period 1963-2005; an initial decline in 1953-1990, but slight recent (1990-2006) recovery in Northern Lapwing; an initial decline in Black-tailed Godwit in the period 1985-1995, but again slight increase from 1995 onwards; no trend in Common Redshank (1992-2006) nor in Eurasian Curlew (1961-2006). In all five species the results indicate that present population declines are caused by a decrease in reproduction, not in adult survival, and that reproductive output is presently too low to compensate for adult mortality. © 2011 Dt. Ornithologen-Gesellschaft e.V. Source


Salewski V.,Michael Otto Institute im NABU | Siebenrock K.-H.,Max Planck Institute for Ornithology (Radolfzell) | Hochachka W.M.,Cornell University | Woog F.,Staatliches Museum fur Naturkunde Stuttgart | Fiedler W.,Max Planck Institute for Ornithology (Radolfzell)
PLoS ONE | Year: 2014

Changes in morphology have been postulated as one of the responses of animals to global warming, with increasing ambient temperatures leading to decreasing body size. However, the results of previous studies are inconsistent. Problems related to the analyses of trends in body size may be related to the short-term nature of data sets, to the selection of surrogates for body size, to the appropriate models for data analyses, and to the interpretation as morphology may change in response to ecological drivers other than climate and irrespective of size. Using generalized additive models, we analysed trends in three morphological traits of 4529 specimens of eleven bird species collected between 1889 and 2010 in southern Germany and adjacent areas. Changes and trends in morphology over time were not consistent when all species and traits were considered. Six of the eleven species displayed a significant association of tarsus length with time but the direction of the association varied. Wing length decreased in the majority of species but there were few significant trends in wing pointedness. Few of the traits were significantly associated with mean ambient temperatures. We argue that although there are significant changes in morphology over time there is no consistent trend for decreasing body size and therefore no support for the hypothesis of decreasing body size because of climate change. Non-consistent trends of change in surrogates for size within species indicate that fluctuations are influenced by factors other than temperature, and that not all surrogates may represent size appropriately. Future analyses should carefully select measures of body size and consider alternative hypotheses for change. © 2014 Salewski et al. Source

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