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  • 201.
    Elmberg, Johan
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Tjernberg, I
    Nilsson, SG
    Forslund, P
    Swanberg, P-O
    Nötkråka2007Other (Other academic)
  • 202.
    Emanuelsson, Urban
    et al.
    Kristianstad University, School of Education and Environment.
    Cousins, Sara
    Eriksson, Ove
    Lindborg, Regina
    Varifrån kommer naturbetesmarkernas arter?2008In: Olsson, R. (red), Mångfaldsmarker: naturbetesmarker - en värdefull resurs, Uppsala: Centrum för biologisk mångfald , 2008, p. 47-52Chapter in book (Other academic)
  • 203.
    Emanuelsson, Urban
    et al.
    Kristianstad University College, School of Teacher Education.
    Dahlström, Anna
    Naturbetesmarker i Sverige och Europa2008In: Olsson, R. (red), Mångfaldsmarker: naturbetesmarker - en värdefull resurs, Uppsala: Centrum för biologisk mångfald , 2008, p. 29-37Chapter in book (Other academic)
  • 204.
    Enquist, Kristoffer
    Kristianstad University, Department of Mathematics and Science.
    Bernstorps mosse - historisk markanvändning och nutida skötsel2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Många våtmarker i slättbygder har under 1900-talet dikats ut och lagts om till åkermark, samtidigt som de kvarvarande fått ta emot allt mer näringsämnen från omgivande marker. Kärr i områden med kalkberggrund är oftast artrika, med flera växt- och djurarter knutna till just dem. Därför är de viktigt att de sköts på ett långsiktigt hållbart sätt. Bernstorps mosse ligger strax utanför Malmö i ett område som präglas av både intensivt jordbruk och utbyggnaden av varuhus och industrier. Uppsatsens syfte har varit att granska hur kärrets sköts just nu och vad som eventuellt kan göras bättre i skötselarbetet. För att svara på frågorna har historiskt kartmaterial och kommunala plandokument granskats, samt en inventering av kärlväxter gjorts. Inga rödlistade arter påträffades vid inventeringen, men resultatet visar att en betesgynnad flora håller på att etablera sig i de delar som hävdas med bete. Skötseln av kärret kan utvecklas på flera sätt, framförallt genom att utöka slåtterytorna. Det går i linje med den historiska markanvändningen, skulle gynna flera konkurrenssvaga arter och även vara ett sätt att minska igenväxningen med bladvass.

  • 205.
    Eriksson, Susanne P.
    et al.
    Department of Biological and Environmental Sciences-Kristineberg, University of Gothenburg.
    Hernroth, Bodil
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Baden, Susanne P.
    Department of Biological and Environmental Sciences-Kristineberg, University of Gothenburg.
    Stress biology and immunology in Nephrops norvegicus2013In: The ecology and biology of Nephrops norvegicus, Amsterdam: Academic Press, 2013, Vol. 64, p. 149-200Chapter in book (Refereed)
    Abstract [en]

    The Norway lobster Nephrops norvegicus lives at low-light depths, in muddy substrata of high organic content where water salinities are high and fluctuations in temperature are moderate. In this environment, the lobsters are naturally exposed to a number of potential stressors, many of them as a result of the surficial breakdown of organic material in the sediment. This process (early diagenesis) creates a heterogeneous environment with temporal and spatial fluctuations in a number of compounds such as oxygen, ammonia, metals, and hydrogen sulphide. In addition to this, there are anthropogenically generated stressors, such as human-induced climate change (resulting in elevated temperature and ocean acidification), pollution and fishing. The lobsters are thus exposed to several stressors, which are strongly linked to the habitat in which the animals live. Here, the capacity of Nephrops to deal with these stressors is summarised. Eutrophication-induced hypoxia and subsequent metal remobilisation from the sediment is a well-documented effect found in some wild Nephrops populations. Compared to many other crustacean species, Nephrops is well adapted to tolerate periods of hypoxia, but prolonged or severe hypoxia, beyond their tolerance level, is common in some areas. When the oxygen concentration in the environment decreases, the bioavailability of redox-sensitive metals such as manganese increases. Manganese is an essential metal, which, taken up in excess, has a toxic effect on several internal systems such as chemosensitivity, nerve transmission and immune defence. Since sediment contains high concentrations of metals in comparison to sea water, lobsters may accumulate both essential and non-essential metals. Different metals have different target tissues, though the hepatopancreas, in general, accumulates high concentrations of most metals. The future scenario of increasing anthropogenic influences on Nephrops habitats may have adverse effects on the fitness of the animals.

  • 206.
    Faurby, Sören
    et al.
    Danmark.
    Jönsson, K. Ingemar
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Rebecchi, L.
    Italien.
    Funch, P.
    Danmark.
    Variation in anhydrobiotic survival of two eutardigrade morphospecies: a story of cryptic species and their dispersal2008In: Journal of Zoology, ISSN 0952-8369, E-ISSN 1469-7998, Vol. 275, no 2, p. 139-145Article in journal (Refereed)
    Abstract [en]

    Studies of geographic variation in anhydrobiotic tolerance may increase our understanding of the population dynamics of terrestrial meiofauna and the relative importance of local adaptation and microhabitat niche separation. Although anhydrobiosis in tardigrades has been studied extensively, few studies have dealt with intraspecific variation in survival and none of these included genetic data to validate the intraspecific nature of the comparisons. Such data are necessary when working with meiofauna as cryptic species are common. We analysed the anhydrobiotic survival and genetic variation in cytochrome oxidase subunit I of two eutardigrades (Richtersius coronifer and Ramazzottius oberhaeuseri) from Italy and Sweden to detect possible local adaptation. Survival was analysed as a multidimensional contingency table and showed that anhydrobiotic survival was higher in Sweden for Ra. oberhaeuseri whereas no significant geographic variation was found for Ri. coronifer. Our genetic analysis indicated the coexistence of two cryptic species of Ra. oberhaeuseri in Italy, only one of which was found in Sweden. It could not be determined whether the variation in Ramazzottius is intra- or interspecific due to the presence of these cryptic species. We suggest that geographic variation in anhydrobiotic survival may be a general phenomenon in tardigrades but further research is necessary to determine the degree of intraspecific variation. The genetic analysis showed indications of long-term isolation of the individual populations of Ri. coronifer but recent dispersal in one of the cryptic species of Ramazzottius. We found higher survival in Ra. oberhaeuseri than in Ri. coronifer. These results indicate a possible coupling between anhydrobiotic survival and dispersal rate.

  • 207.
    Felton, Adam
    et al.
    Swedish University of Agricultural Sciences, Alnarp.
    Lindbladh, Matts
    Swedish University of Agricultural Sciences, Alnarp.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Felton, Annika M.
    Swedish University of Agricultural Sciences, Alnarp.
    Andersson, Erik
    Stockholm University.
    Sekercioglu, Cagan H.
    University of Utah.
    Collingham, Yvonne
    Durham University.
    Huntley, Brian
    Durham University.
    Projecting impacts of anthropogenic climatic change on the bird communities of southern Swedish spruce monocultures: will the species poor get poorer?2014In: Ornis Fennica, ISSN 0030-5685, Vol. 91, no 1, p. 1-13Article in journal (Refereed)
    Abstract [en]

    The potential impact of climatic change on bird species’ distributions in Europe was recently modeled for several scenarios of projected late 21st century climate. The results indicate mean range shifts of hundreds of kilometres north for many of European bird species. Here we consider the implications from such distributional shifts for the bird communities of Norway spruce (Picea abies) monocultures in southern Sweden, a forest type likely to remain prevalent due to forestry, despite climate change. Our assessment led us to three key findings. First, the monocultures offer suitable habitat to only two bird species projected to extend their breeding distribution northwards into southern Sweden this century. Second, species richness was projected to decline overall, which would accentuate the depauperate nature of these stands. Third, all conifer-associated arboreal granivores and three of four conifer-associated arboreal insectivores were projected not to occur, reducing both the functional richness and functional redundancy. We discuss caveats related to our approach, including the potential for bioclimatic projections – used in this study – to be hampered by the artificial retention of dominant vegetation. We also discuss the implications of our results for avian biodiversity in what is today the most prevalent forest type in southern Sweden and in many other regions of Europe.

  • 208.
    Filling, Julia
    Kristianstad University, Faculty of Natural Science.
    Human Urine: can it be applied as fertilizer in agricultural systems?2018Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    In cities today, vast amounts of nutrients are being wasted. Improvement in nutrient management within agriculture can contribute to a more sustainable society. Reusing nutrients in agriculture could aid in creating a more circular system, where organic fertilizers can be used instead of chemical fertilizers. Urine is a liquid which has a high nutrient content. According to the Swedish environmental protection agency, human urine can replace mineral fertilizers, by using methods such as source separation, where urine is divided from faeces. This is a cheap, effective and sustainable fertilizer management system that can be easily achieved. In this study, urine fertilizers were compared with ecological and conventional fertilizers (NPK and cow manure). The study examined the effect of different urine fertilizers compared with organic and inorganic ones on plant growth, nutrient content, pH value and microbial growth. The plant growth experiment was carried out in the greenhouse facilities in Alnarp, Sweden. The results from the experiment show that cow manure has a better outcome when it comes to plant growth, but Aurin, one of the urine fertilizers, had the highest uptake of nitrate. Non-diluted urine had a stable result in all analyses. According to this study human urine is a fertilizer which can be used in crop cultivation systems, and can deliver good agricultural results.

  • 209.
    Forkman, Jonatan
    Kristianstad University, School of Education and Environment.
    Spindelfaunan i granplanteringar av olika åldrar: En undersökning från södra Skåne2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To determine whether the spider communities in spruce Picea abies plantations in southern Sweden differ between trees of various ages, the spiders from minor, young and older trees has been collected during May and June 2016. The minor trees were 1.5–2.0 m, the young trees were 19–20 m and the older trees were over 22 m high. The spiders were collected from five plantations of each age category and from ten trees in each plantation. The spiders from ten of the dead branches inside of each older plantation were collected as well. 59 different species were found and all together 970 spider specimens were collected. The results showed many different things, for example that the species on the dead branches were mainly web spiders and that many of the species on the minor trees prefer the field layer as habitat. My study was compared to three other spider studies, one from Sweden, one from the Czech Republic and one from Norway. The comparison showed differences in the collected spider species which could be explained by the various methods used in the different studies and whether the spiders in the study had been collected during early summer or throughout the whole season. The spiders collected in this study could in the future be used to detect changes in the spider fauna caused by climate change.  

  • 210.
    Fox, Anthony D.
    et al.
    Danmark.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Tombre, Ingunn M.
    Norge.
    Hessel, Rebecca
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Agriculture and herbivorous waterfowl: a review of the scientific basis for improved management2017In: Biological Reviews, ISSN 1464-7931, E-ISSN 1469-185X, Vol. 92, no 2, p. 854-877Article in journal (Refereed)
    Abstract [en]

    Swans, geese and some ducks (Anatidae) are obligate herbivores, many are important quarry species and all contribute to a variety of ecosystem services. Population growth and shifting ranges have led to increasing proximity to man and thus increasing conflicts. We review and synthesize the role of these birds as herbivores on agricultural land (cropland, rotational grassland and pasture) and other terrestrial habitats where conflict with human interests may occur. A bibliographic analysis of peer-reviewed papers (N = 359) shows that publication activity peaked in 1991-2000 in North America and 2000-2010 in Europe, and has decreased since. Taxonomic and geographical biases are obvious in research to date: Snow Goose Chen caerulescens was the most studied species (N = 98), and Canada Branta canadensis, Barnacle B. leucopsis and Brent geese B. bernicla all featured in more than 40 studies; most studies originated in northwest Europe or North America, very few have been carried out in Asia and European Russia. On the basis of nutrient/energy budgets of herbivorous waterfowl, it is evident that dense single-species crops (such as rotational grassland, early-growth cereals and root crops) and spilled grain in agricultural landscapes offer elevated energetic and nutritional intake rates of food of higher quality compared to natural or semi-natural vegetation. Hence, although affected by seasonal nutritional demands, proximity to roost, field size, disturbance levels, access to water, food depletion and snow cover, agricultural landscapes tend to offer superior foraging opportunities over natural habitats, creating potential conflict with agriculture. Herbivorous waterfowl select for high protein, soluble carbohydrate and water content, high digestibility as well as low fibre and phenolic compounds, but intake rates from grazing varied with goose body and bill morphology, creating species-specific loci for conflict. Crop damage by trampling and puddling has not been demonstrated convincingly, nor do waterfowl faeces deter grazing stock, but where consumption of crops evidently reduces yields this causes conflict with farmers. Studies show that it is difficult and expensive to assess the precise impacts of waterfowl feeding on yield loss because of other sources of variation. However, less damage has been documented from winter grazing compared to spring grazing and yield loss after spring grazing on grassland appears more pronounced than losses on cereal fields. Although yield losses at national scales are trivial, individual farmers in areas of greatest waterfowl feeding concentrations suffer disproportionately, necessitating improved solutions to conflict. Accordingly, we review the efficacy of population management, disturbance, provision of alternative feeding areas, compensation and large-scale stakeholder involvement and co-management as options for resolving conflict based on the existing literature and present a framework of management advice for the future. We conclude with an assessment of the research needs for the immediate future to inform policy development, improve management of waterfowl populations and reduce conflict with agriculture.

  • 211.
    Fox, Anthony D.
    et al.
    Aarhus University.
    Jonsson, Jon Einar
    University of Iceland.
    Aarvak, Tomas
    Norwegian Ornithological Society .
    Bregnballe, Thomas
    Aarhus University.
    Christensen, Thomas Kjaer
    Aarhus University.
    Clausen, Kevin Kuhlmann
    Aarhus University.
    Clausen, Preben
    Aarhus University.
    Dalby, Lars
    Aarhus University.
    Holm, Thomas Eske
    Aarhus University.
    Pavon-Jordan, Diego
    University of Helsinki.
    Laursen, Karsten
    Aarhus University.
    Lehikoinen, Aleksi
    University of Helsinki.
    Lorentsen, Svein-Hakon
    Norwegian Institute for Nature Research.
    Moller, Anders Pape
    University of Paris .
    Nordstrom, Mikael
    Metsahallitus Pk & Wildlife, Finland.
    Ost, Markus
    Åbo Akademi University.
    Soderquist, Par
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Therkildsen, Ole Roland
    Aarhus University.
    Current and potential threats to Nordic duck populations - a horizon scanning exercise2015In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 52, no 4, p. 193-220Article in journal (Refereed)
    Abstract [en]

    We review the current and future threats to duck populations that breed, stage, moult and/or winter in the Nordic countries. Migratory duck species are sensitive indicators of their changing environment, and their societal value confirms the need to translate signals from changes in their distribution, status and abundance into a better understanding of changes occurring in their wetland environments. We used expert opinion to highlight 25 major areas of anthropogenic change (and touch briefly on potential mitigation measures through nature restoration and reserve management projects) that we consider key issues likely to influence Nordic duck populations now and in the near future to stimulate debate, discussion and further research. We believe such reviews are essential in contributing to development of successful management policy as well as stimulating specific research to support the maintenance of duck species in favourable future conservation status in the face of multiple population pressures and drivers.

  • 212. Gillman, Anna
    et al.
    Muradrasoli, Shaman
    Söderström, Hanna
    Holmberg, Fredrik
    Latorre-Margalef, Neus
    Tolf, Conny
    Waldenström, Jonas
    Gunnarsson, Gunnar
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Olsen, Björn
    Järhult, Josef D
    Oseltamivir-Resistant Influenza A (H1N1) Virus Strain with an H274Y Mutation in Neuraminidase Persists without Drug Pressure in Infected Mallards2015In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 81, no 7, p. 2378-2383Article in journal (Refereed)
    Abstract [en]

    Influenza A virus (IAV) has its natural reservoir in wild waterfowl and emerging human IAVs often contain gene segments from avian viruses. The active drug metabolite of oseltamivir (oseltamivir carboxylate (OC)), stockpiled as Tamiflu® for influenza pandemic preparedness, is not removed by conventional sewage treatment and has been detected in river water. There, it may there exert evolutionary pressure on avian IAV in waterfowl, resulting in development of resistant viral variants. A resistant avian IAV can circulate among wild birds only if resistance does not restrict viral fitness and if the resistant virus can persist without continuous drug pressure. In this in vivo Mallard (Anas platyrhynchos) study we tested if an OC-resistant avian IAV strain (A(H1N1)/NA-H274Y) could retain resistance while drug pressure was gradually removed. Successively infected Mallards were exposed to decreasing levels of OC, and fecal samples were analyzed for neuraminidase sequence and phenotypic resistance. No reversion to wild-type virus was observed during the experiment, which included 17 days of viral transmission in 10 ducks exposed to OC concentrations below resistance induction levels. We conclude that resistance in avian IAV, induced by OC exposure of the natural host, can persist in absence of the drug. Thus, there is a risk that human pathogenic IAVs that evolve from IAVs circulating among wild birds may contain resistance mutations. An oseltamivir resistant pandemic IAV would be a substantial public health threat. Therefore, our observations underscore the need for prudent oseltamivir use, upgraded sewage treatment and resistance surveillance of IAV in wild birds.

  • 213. Godhe, A.
    et al.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Musselgifternas förekomst regleras av oceanografiska förhållanden2002In: Havsmiljön: aktuell rapport om miljötillståndet i Kattegat, Skagerrak och Öresund. Juni 2002, Göteborg: Göteborgs universitets marina forskningscentrum , 2002Chapter in book (Other academic)
  • 214.
    Godhe, Anna
    et al.
    Marine Botany, Department of Marine Ecology, Göteborg University.
    Anderson, Donald M.
    Biology Department, Woods Hole Oceanographic Institution, Woods Hole.
    Rehnstam-Holm, Ann-Sofi
    Biology Department, Woods Hole Oceanographic Institution, Woods Hole.
    PCR amplification of microalgal DNA for sequencing and species identification: studies on fixatives and algal growth stages2002In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 1, no 4, p. 375-382Article in journal (Refereed)
    Abstract [en]

    Cultured strains and individually isolated dinoflagellate cells from field samples were preserved in different fixatives to find a method of cell preservation that could provide DNA template in PCR reactions and preserve cell morphology for microscopic studies. Lugol’s solution and various ethanol concentrations all showed shortcomings, whereas an initial formalin preservation step followed by storage in 100% methanol fulfilled both demands. Cells could be stored up to 1 year and still provide functional DNA template for positive PCR reactions. The amplified fragment was approximately 700 bp of the D1/D2 region of the LSU rDNA, which is to our knowledge significantly longer than the low-molecular-weight DNA typically reported from formalin preserved samples. By cloning and sequencing the PCR product and subsequently aligning the sequences with previously sequenced fragments of the same or similar species, we confirmed that no base pair alteration had taken place during the time that the cells were fixed and frozen. In another experiment it was demonstrated that the growth phase of cultured Alexandrium minutum did not have any influence on the result of PCR reactions. This was true for extracted DNA from cultures and for direct PCR with a small number of disrupted cells. Phenol/chlorophorm/isoamylalcohol extraction proved to be an unpredictable method for DNA extraction, whereas direct PCR on isolated cells was more reliable. Extracted DNA purified with a commercial DNA cleaning kit always rendered a positive PCR. The environmental condition for cells to be used as DNA template in PCR is discussed.

  • 215.
    Godhe, Anna
    et al.
    Department of Marine Ecology, Marine Botany, Göteborg University.
    McQuoid, Melissa R.
    Department of Marine Ecology, Marine Botany, Göteborg University.
    Karunasagar, Indrana
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore.
    Karunasagar, Iddya
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Comparison of three common molecular tools for distinguishing among geographically separated clones of the diatom Skeletonema marinoi Sarno et Zingone (bacillariophyceae)2006In: Journal of Phycology, ISSN 0022-3646, E-ISSN 1529-8817, Vol. 42, no 2, p. 280-291Article in journal (Refereed)
    Abstract [en]

    Skeletonema marinoi Sarno et Zingone is a planktonic marine diatom with a widespread geographic distribution. Different populations of this species may show distinct genetic signatures. We have evaluated the utility of three common molecular methods for distinguishing clones of S. marinoi from different geographic regions. Clonal cultures were isolated from the Canadian west coast, south west Portugal, and the east and west coasts of Sweden. All strains originated from resting stages in sediment. More than 90% of the individually isolated chains grew to densities suitable for DNA extraction. Genetic signatures of clones from each sample location were assessed by sequencing variable domains (D1-D3) of the nuclear large subunit (LSU) rRNA gene and internal transcriber spacer (ITS) (ITS-1, 5.8S and ITS-2) regions, and also by analysis of randomly amplified polymorphic DNA patterns. Analysis of molecular variance showed that strains from the four geographic areas were significantly separated by all three methods but that differences among European samples were best resolved by ITS 2 sequences.

  • 216.
    Godhe, Anna
    et al.
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore, India.
    Otta, S. K.
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore, India.
    Rehnstam-Holm, Ann-Sofi
    Clinical Bacteriology, Göteborg University.
    Karunasagar, Indrani
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore, India.
    Karunasagar, Iddya
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore, India.
    Polymerase chain reaction in detection of Gymnodinium mikimotoi and Alexandrium minutum in field samples from Southwest India2001In: Marine Biotechnology, ISSN 1436-2228, E-ISSN 1436-2236, Vol. 3, no 2, p. 152-162Article in journal (Refereed)
    Abstract [en]

    Polymerase chain reaction (PCR) primers were constructed for the detection of two toxic dinoflagellate species, Gymnodinium mikimotoi and Alexandrium minutum. The primers amplified a product of expected size from cultured cells of G. mikimotoi and A. minutum. The species-specific primers targeting G. mikimotoi did not yield any product with a wide range of other cultured algae used as negative controls. Primers designed for A. minutum were species-group-specific since it PCR yielded a product from the closely related species A. ostenfeldii and A. andersonii, but not from other species of this genus tested. The confirmation of PCR products was performed by digestion of the products with restriction enzymes. Sensitivity analyses of the primers on DNA template from cultured cells was positive by PCR at a DNA template concentration of 1.5 x 10(-4) ng/microl (0.3 cells/L) for A. minutum, and at a DNA concentration of 2.5 x 10(-2) ng/microl (697 cells/L) for G. mikimotoi. The PCR method for detection of G. mikimotoi and A. minutum was applied on field samples collected with a plankton net. Gymnodinium mikimotoi could be detected in 11 field samples by microscopy, and all these field samples were positive by PCR. The cell counts of G. mikimotoi in simultaneously collected water samples ranged from 306 to 2077/L. Alexandrium minutum could be detected by microscopy in 3 different field samples. The cell counts in water samples collected at the same time as the net samples ranged from 115 to 1115 cells/L. Alexandrium minutum was detected by PCR in these field samples, with the exception of the sample displaying the lowest cell count (115 cells/L). Plankton samples that were negative by microscopy for any of the two target species were also negative by PCR. All the PCR products from field samples were confirmed by restriction enzyme digestion. The application of PCR-based detection of harmful algal bloom species for aquaculture and monitoring purposes in natural field samples is discussed.

  • 217.
    Godhe, Anna
    et al.
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Karunasagar, Indrani
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore.
    Karunasagar, Iddya
    Department of Fishery Microbiology, College of Fisheries, University of Agricultural Sciences, Mangalore.
    PCR detection of dinoflagellate cysts in field sediment samples from tropic and temperate environments2002In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 1, no 4, p. 361-373Article in journal (Refereed)
    Abstract [en]

    Species-specific primers were constructed for Scrippsiella trochoidea, Protoceratium reticulatum and Lingulodinium polyedrum, which all are common cosmopolitan cyst forming dinoflagellates. The designed primers amplified a product of expected size from cultured planktonic cells of the three species, and did not yield any product with a wide range of other algal species used as negative controls. The PCR method for detection and identification of dinoflagellate cysts from the three species was applied on field samples. Undisturbed surface sediment was collected along the southwest coast of India and the west coast of Sweden. DNA extract from sediment including DNA from dinoflagellate cysts could be obtained after repeated grinding with mortar and pestle under liquid nitrogen followed by microwave boiling. All sediment samples that contained any of the target species as confirmed by microscopy, were also positive for PCR. Field samples negative for any of the target species by microscopy, were also negative by PCR. Restriction enzyme digestion and/or DNA sequencing confirmed the specificity of all the PCR products from field samples. The yield of DNA from sediment extraction was low, and therefore nested PCR was necessary for accurate species-specific detection of the three species in most of the field samples.

  • 218.
    Godhe, Anna
    et al.
    Marine Botany, Department of Marine Ecology, Göteborg University.
    Svensson, Susanne
    Department of Zoophysiology, Göteborg University.
    Rehnstam-Holm, Ann-Sofi
    Clinical Bacteriology, Göteborg University.
    Oceanographic settings explain fluctuations in Dinophysis spp. and concentrations of diarrhetic shellfish toxin in the plankton community within a mussel farm area on the Swedish west coast2002In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 240, p. 71-83Article in journal (Refereed)
    Abstract [en]

    The influence of hydrographic, biological and meteorological variables on the abundance of Dinophysis spp. and the concentration of diarrhetic shellfish toxin (DST) in the plankton population were investigated in a mussel (Mytilus edulis) farm area on the Swedish west coast. This location provided an opportunity to simultaneously compare Dinophysis spp. cell numbers, concentration of DST in natural phytoplankton assemblages and toxicity of mussel tissues. Sampling was performed every other day from October 10 to November 5, 2000, and on each occasion, 5 randomly selected sites were sampled. During this period, 3 distinct water masses passed through the vicinity of the mussel farm. The second water mass, characterized by low salinity and nitrogen concentration, was probably advected into the area from surface waters in the nearby Skagerrak. This low salinity water also contained a high abundance of Dinophysis spp., and high concentrations of DST were recorded in the phytoplankton population. Multivariate analysis (projection to latent structures by means of partial least squares, PLS) determined that the principal variables influencing the concentration of DST in the plankton assemblage were the causative species (D. acuminata, D. acuta and D. norvegica) and salinity. The abundance of the 3 Dinophysis spp. was inversely correlated to salinity. A rapid increase in the toxicity of mussels in response to the high levels of DST was observed. The concentration of DST had doubled within 2 d of the appearance of Dinophysis spp. After 8 d, the water mass containing Dinophysis spp. was replaced and cell numbers again returned to low levels. The concentration of DST in the phytoplankton samples remained high for another 2 d after the number of Dinophysis spp. had declined and the toxicity of mussels continued to be high for the remainder of the study. Causes of the rapid intoxication versus slow detoxification of mussels are discussed. These results suggest that present monitoring programs are insufficient to provide early warning of toxic blooms to aquaculturists on the Swedish west coast.

  • 219.
    Golas, Marta
    et al.
    Polen.
    Czernekova, Michaela
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH). Charles University, Prague.
    Hyra, Marta
    Polen.
    Janelt, Kamil
    Polen.
    Poprawa, Izabela
    Polen.
    Organisation of the capsule of Macrobiotus pallari and Richtersius coronifer (Tardigrada, Eutardigrada, Parachela)2016In: ACTA BIOLOGICA CRACOVIENSIA, 2016, Vol. 58, p. 74-Conference paper (Refereed)
    Abstract [en]

    Organisation of the egg capsule of two species of tardigrades belonging to the family Macrobiotidae, Macrobiotus pallari and Richtersius coronifer, was analysed using light, transmission and scanning electron microscopy. In both cases, similar to other Macrobiotidae (Węglarska, 1982; Poprawa etal., 2015) egg capsule was composed of thin vitelline envelope and three-layered chorion. The chorion consisted of: (1) the inner, medium electron-dense layer – endochorion, (2) the middle, labyrinthine layer and (3) the outer, medium electron-dense layer – exochorion. The yellow chorion of Richtersius coronifer was covered with elongated processes having irregular granulation ontheir surface. These processes were empty inside. They were formed by evagination of exochorion. The basic chorion connecting processes was smooth and covered with irregular granulation. The chorion of Macrobiotus pallari was white. Its surface was covered with conical processes and areolation between them. The tips of processes were elongated and formed bushy structure. The surface of conical processes has a form of sculpture composed of thin rings. The processes that were empty inside, were formed by evagination of exochorion and labyrinthine layer.

  • 220.
    Green, Andy J.
    et al.
    Estación Biológica de Doñana, CSIC, Sevilla.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Ecosystem services provided by waterbirds2014In: Biological Reviews, ISSN 1464-7931, E-ISSN 1469-185X, Vol. 89, no 1, p. 105-122Article in journal (Refereed)
    Abstract [en]

    Ecosystem services are ecosystem processes that directly or indirectly benefit human well-being. There has been much recent literature identifying different services and the communities and species that provide them. This is a vital first step towards management and maintenance of these services. In this review, we specifically address the waterbirds, which play key functional roles in many aquatic ecosystems, including as predators, herbivores and vectors of seeds, invertebrates and nutrients, although these roles have often been overlooked. Waterbirds can maintain the diversity of other organisms, control pests, be effective bioindicators of ecological conditions, and act as sentinels of potential disease outbreaks. They also provide important provisioning (meat, feathers, eggs, etc.) and cultural services to both indigenous and westernized societies. We identify key gaps in the understanding of ecosystem services provided by waterbirds and areas for future research required to clarify their functional role in ecosystems and the services they provide. We consider how the economic value of these services could be calculated, giving some examples. Such valuation will provide powerful arguments for waterbird conservation.

  • 221.
    Green, Andy J.
    et al.
    Spain.
    Elmberg, Johan
    Kristianstad University, Faculty of Natural Science, Research environment Man & Biosphere Health (MABH). Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap.
    Lovas-Kiss, Adam
    Hungary.
    Beyond Scatter-Hoarding and Frugivory: European Corvids as Overlooked Vectors for a Broad Range of Plants2019In: Frontiers in Ecology and Evolution, E-ISSN 2296-701X, Vol. 7, article id 133Article in journal (Refereed)
    Abstract [en]

    It is well-known that some members of the crow family (Corvidae) are important for seed dispersal either via frugivory (e.g., when feeding on berries) or by scatter hoarding (e.g., of nuts). Dispersal via gut passage of seeds within a fleshy fruit can be considered "classical endozoochory." However, corvids are rarely recognized as vectors of plants lacking a fleshy fruit, or a large nut (such as plants with a dry achene, capsule or caryopsis). Dispersal of such seeds via gut passage can be considered "non-classical endozoochory." A century ago, Heintze (1917a,b); Heintze (1918) reported on extensive field studies of seed dispersal by 11 species of European Corvidae. His work is overlooked in contemporary reviews of corvid biology. We resurrect his work, which suggests that contemporary views about seed dispersal by corvids are too narrow. Heintze identified 157 plant taxa from 42 families which were dispersed by corvids by endozoochory, as well as another nine taxa only dispersed by synzoochory (which includes scatter-hoarding). Most (54%) of the plant species dispersed by endozoochory lack a fleshy fruit and have previously been assigned to other dispersal syndromes, mainly associated with wind (10%), self-dispersal (22%) or epizoochory (18%). Plants lacking a fleshy fruit were particularly well-represented from the Caryophyllaceae (12 species), Poaceae (14 species), and Polygonaceae (8 species). Of 27 taxa germinated by Heintze from seeds extracted from corvid pellets or feces (71% of those tested), 20 lack a fleshy fruit. Similarly, of 32 taxa he recorded as seedlings having germinated from pellets in the field, 11 lacked a fleshy fruit. However, Heintze's quantitative data show that classical endozoochory is dominant in Magpies Pica pica and Hooded Crows Corvus cornix, for which 97% of seeds dispersed were fleshy-fruited. Corvids overlap with waterfowl as vectors of terrestrial plants dispersed by non-classical endozoochory, and 56 species are dispersed by both corvids and dabbling ducks according to the lists of Heintze and Soons et al. (2016). Finally, Heintze's data show that corvids were already dispersing alien plants in Europe a century ago, such as the North American Dwarf Serviceberry Amelanchier spicata.

  • 222.
    Grönroos, Johanna
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Strandberg, Roine
    Lunds universitet.
    Olofsson, Patrik
    Alerstam, Thomas
    Lunds universitet.
    Klaassen, Raymond
    Skånska tärnors flyttning - ett forskningsprojekt2016In: Anser, ISSN 0347-9595, no 1, p. 20-26Article in journal (Other (popular science, discussion, etc.))
  • 223.
    Guidetti, Roberto
    et al.
    Italien.
    Rebecchi, Lorena
    Italien.
    Bertolani, Roberto
    Italien.
    Jönsson, K. Ingemar
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Kristensen, Reinhardt M.
    Danmark.
    Cesari, Michele
    Italien.
    Morphological and molecular analyses on Richtersius (Eutardigrada) diversity reveal its new systematic position and lead to the establishment of a new genus and a new family within Macrobiotoidea2016In: Zoological Journal of the Linnean Society, ISSN 0024-4082, E-ISSN 1096-3642, Vol. 178, no 4, p. 834-845Article in journal (Refereed)
    Abstract [en]

    Important contributions have been made to the systematics of Eutardigrada in recent years, but these have also revealed that several taxa are polyphyletic and that cryptic species are present. To shed light on the taxonomy and systematic position of the genus Richtersius (Eutardigrada, Macrobiotoidea), six populations attributed to Richtersius coronifer were collected and analysed from morphological (light and scanning electron microscopy) and molecular (mitochondrial cytochrome oxidase subunit 1, 18S, 28S) points of view. In particular, a new morphometric index (claw common tract: length of the common tract of the claw/total claw length × 100) and a new morphological character (stalk system) were introduced. Our integrative study was able to unveil the ‘cryptic’ species diversity within Richtersius, showing that the genus contains more than one evolutionary lineage. A morphological peculiarity in the animals of all lineages is the dimorphism in the morphology of the cuticle. Cuticular pores are present in the newborns and are lost with the first moult; this morphological change represents a novelty in the life cycle of eutardigrades. The phylogenetic analyses carried out on Richtersius populations and other Macrobiotoidea show that Richtersius is closely related to Macrobiotus islandicus, whereas Adorybiotus granulatus is more related to Richtersius and M. islandicus than to other members of the genus Macrobiotus (type genus of Macrobiotidae); therefore, the genus Macrobiotus and the family Macrobiotidae are not monophyletic. Based on these results, the new genus Diaforobiotus (for M. islandicus) and the new family Richtersiidae (composed of Richtersius, Diaforobiotus gen. nov., and Adorybiotus) are established.

  • 224.
    Guillemain, M.
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Elmberg, Johan
    Kristianstad University, Department of Mathematics and Science.
    Arzel, C.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Johnson, A. R.
    Station Biologique de la Tour du Valat, le Sambuc, Arles.
    Simon, G.
    Station Biologique de la Tour du Valat, le Sambuc, Arles.
    The income–capital breeding dichotomy revisited: late winter body condition is related to breeding success in an income breeder2008In: Ibis, ISSN 0019-1019, E-ISSN 1474-919X, Vol. 150, no 1, p. 172-176Article in journal (Refereed)
  • 225.
    Guillemain, Matthieu
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Arzel, Céline
    Kristianstad University, Department of Mathematics and Science.
    Legagneux, Pierre
    Centre d'Etudes Biologiques de Chizé - CNRS UPR 1934, Beauvoir-sur-Niort.
    Elmberg, Johan
    Kristianstad University, Department of Mathematics and Science.
    Fritz, Hervé
    Centre d'Etudes Biologiques de Chizé - CNRS UPR 1934, Beauvoir-sur-Niort.
    Lepley, Michel
    Station Biologique de la Tour du Valat, Le Sambuc, Arles.
    Pin, Christophe
    Les Marais du Vigueirat, Mas Thibert, Arles.
    Arnaud, Antoine
    Station Biologique de la Tour du Valat, Le Sambuc, Arles.
    Massez, Grégoire
    Les Marais du Vigueirat, Mas Thibert, Arles.
    Predation risk constrains the plasticity of foraging behaviour in teals, Anas crecca: a flyway-level circumannual approach2007In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 73, no 5, p. 845-854Article in journal (Refereed)
    Abstract [en]

    The trade-off foragers make between predation risk and feeding efficiency is readily studied in dabbling ducks, which have stereotyped feeding methods, some of which prevent predator detection while others do not. Teals forage mostly with only the bill submerged (eyes above the water surface) in winter, but use a broader foraging repertoire in summer. Given the different environments used by teals over the year, it is likely that such a shift is due to changes in diet, but it may also be caused by differences in predation risk between habitats. However, neither predation risk nor teal behaviour has been studied with consistent methods around the year or throughout any of its flyways. Covering wintering, spring-staging, breeding and moulting sites, we combined focal observations of teals and predator flyover data from seven regions ranging from southern France to northern Sweden. Although not apparent at the scale of days within sites, teals indeed relied more on shallow foraging where predation risk was higher, i.e. at wintering sites. Average foraging depth increased gradually from September to August, i.e. from wintering to breeding sites. Foraging bout length of deeply foraging teals did not decrease over the year, suggesting that it is through selection of foraging technique, rather than by the balance between foraging and interruptions, that birds adjust to predation risk. This study highlights behavioural plasticity in response to contrasting selection regimes within a flyway, in dabbling ducks as well as long-distance migrants in general.

  • 226.
    Guillemain, Matthieu
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice , La Tour du Valat, Le Sambuc, Arles.
    Arzel, Céline
    Kristianstad University, Department of Mathematics and Science.
    Legagneux, Pierre
    Centre d’Etudes Biologiques de Chizé, CNRS UPR 1934, Beauvoir sur Niort.
    Elmberg, Johan
    Kristianstad University, Department of Mathematics and Science.
    Fritz, Hervé
    Centre d’Etudes Biologiques de Chizé, CNRS UPR 1934, Beauvoir sur Niort.
    Lepley, Michel
    Station Biologique de la Tour du Valat, Le Sambuc, Arles.
    Pin, Christophe
    Station Biologique de la Tour du Valat, Le Sambuc, Arles.
    Arnaud, Antoine
    Station Biologique de la Tour du Valat, Le Sambuc, Arles.
    Massez, Grégoire
    Les Marais du Vigueirat, Mas Thibert, Arles.
    Risky foraging leads to cost-free mate guarding in male teal Anas crecca2007In: Journal of Ornithology = Journal fur Ornithologie, ISSN 0021-8375, E-ISSN 1439-0361, Vol. 148, no 2, p. 251-254Article in journal (Refereed)
    Abstract [en]

    Mate guarding by males is common in species with long-lasting pair bonds. We tested if the need to guard females affected foraging depth in male teal (Anas crecca), and if they were more vigilant than females when foraging with submerged eyes (preventing monitoring of competing males and predators). These predictions were not supported, suggesting that foraging depth selection is primarily driven by other factors, presumably food related. A likely reason why deeply foraging males did not increase vigilance is that 37.5% of the foraging time was already dedicated to it. The apparent lack of guarding costs in foraging male teal may explain why such small ducks can maintain pair bonds for up to 7 months.

  • 227.
    Guillemain, Matthieu
    et al.
    Frankrike.
    Champagnon, Jocelyn
    Frankrike.
    Pernollet, Claire A.
    Frankrike.
    Devineau, Olivier
    Norge.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Cavallo, François
    Frankrike.
    Massez, Grégoire
    Frankrike.
    Combined effects of climate change and fluctuating habitat quality on the distribution of ducks in southern Europe2016In: 7th North American Duck Symposium: waterfowl ecology and adaptive management, 2016Conference paper (Refereed)
    Abstract [en]

    Changes in waterfowl ranges over the last decades are increasingly reported, both in North America and in Europe. The relative importance of different winter quarters may fluctuate under the influence of changing local habitat conditions, as well as according to general trends caused by global climate change. Several European duck species have shifted their winter range to the North-East, i.e. the distance between breeding and wintering grounds was reduced, in a pattern consistent with a global temperature increase. In northern countries, this could also indicate an increasing proportion of sedentary birds. We compared the geographic distribution of recoveries of bands fitted to Mallard (Anas platyrhynchos) and Common Teal (A. crecca) in Camargue, southern France, over the last 60 years. Close to 75,000 ducks were banded since the early 1950s. Band recoveries occurred to a much greater extent in the Camargue area than in other parts of the flyways during the last decade compared to earlier years: as opposed to earlier studies, recoveries of Camargue-ringed ducks are increasingly made to the South-West. For migratory Teal, this indicates an increased faithfulness to the Camargue winter quarter. For Mallard, though, some birds may have become around-the-year residents: while the distance from banding site to recovery location was >400 km between the 1950s and 1970s, it is <75 km nowadays. Several hypotheses are proposed to explain these changes in European duck distributions. Survival analyses are also carried out, which help assessing whether changes in geographic distribution have also translated into altered demographic rates. Besides the overriding effects of climate change in the long-term, the present results suggest that local habitat management practices still have the potential to greatly affect the distribution of waterfowl.

  • 228.
    Guillemain, Matthieu
    et al.
    Frankrike.
    Champagnon, Jocelyn
    Frankrike.
    Pernollet, Claire A.
    Frankrike.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Mouronval, Jean-Baptiste
    Frankrike.
    Massez, Grégoire
    Frankrike.
    Still worth the travel?: changes in Camargue teal migration patterns, body condition and demographic parameters over 60 years2015In: 4th Pan-European Duck Symposium, Hangö, Finland, 8-11/4 2015, 2015, p. 28-Conference paper (Refereed)
    Abstract [en]

    Climate and habitat changes linked with human activities have profoundly modified the road maps of waterfowl across their geographic ranges. If new breeding grounds open to the North, traditional wintering sites may gradually get deserted by birds short-stopping during the autumn and shifting their nonbreeding distribution. More than 60,000 ringing data were collected from wintering Teal (Anas crecca) in the area from the early 1950s to the beginning of the 2010s. Migration patterns have changed with birds now arriving much earlier, and overall population movements being much reduced during winter. The body condition of Camargue-wintering Teal has improved dramatically compared to the pre-1970 era, which could be a cause and/or a consequence of such changes in migration processes: Teal may arrive increasingly early in the year because artificial summer flooding of wetlands and baiting now provide suitable habitat and abundant accessible food. In turn, reduced movements linked with greater residency in the Camargue would impose smaller use of the body reserves. The comparison of Teal turnover and survival rates during historical (1950s- 1970s) and modern (post-2002) years provides some insight as to whether the situation has gradually improved for these birds. Conversely, the sustained use of the Camargue could simply reflect these birds being lured by artificially increased availability of food, which they would use at the expense of their survival rate, hence with no positive consequences in terms of population dynamics.

  • 229.
    Guillemain, Matthieu
    et al.
    Frankrike.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    The teal2014Book (Refereed)
    Abstract [en]

    Small, noisy and colourful, the Teal is a familiar duck throughout the wetlands and waterways Europe and Asia. Once hunted extensively for the pot, its numbers have recovered and it is now one of our commonest species of waterfowl.

    A flagship species for wetland conservation, the Teal is also an excellent model species for ecological research, and this forms the spine of this new Poyser monograph.

    The Teal looks at distribution and trends in numbers, foraging ecology, breeding behaviour), population dynamics, management and conservation of teal, looking at both the Eurasian Common Teal and its North American equivalent, the Green-winged Teal (which until relatively recently was considered to be the same species). The book provides a scientifically robust account on which wetland managers, research scientists and the ornithological community may rely, with wider implicatons for the conservation and management of other waterfowl, and for ecological research in general.

  • 230.
    Guillemain, Matthieu
    et al.
    Frankrike.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Arzel, Céline
    Finland.
    Johnson, AR
    Simon, G
    Linking wintering and breeding grounds: good winter conditions are associated with higher breeding success in Teal Anas crecca2007In: Book of abstracts: International Union of Game Biologists XXVIII Congress, 13-18 August, 2007 / [ed] K.I. Sjöberg & T. Rooke, 2007, p. 285-Conference paper (Refereed)
  • 231.
    Guillemain, Matthieu
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice La Tour du Valat, Le Sambuc, Arles.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Gauthier-Clerc, Michel
    Centre de Recherche de la Tour du Valat Le Sambuc, Arles.
    Massez, Grégoire
    Les Marais du Vigueirat Mas Thibert, Arles .
    Hearn, Richard
    Wildfowl & Wetlands Trust, Slimbridge, Gloucester.
    Champagnon, Jocelyn
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice La Tour du Valat, Le Sambuc, Arles .
    Simon, Géraldine
    Centre de Recherche de la Tour du Valat Le Sambuc, Arles .
    Wintering French mallard and teal are heavier and in better body condition than 30 years ago: effects of a changing environment?2010In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 39, no 2, p. 170-180Article in journal (Refereed)
    Abstract [en]

    Animal populations are exposed to large-scale anthropogenic impact from e.g. climate change, habitat alteration and supplemental stocking. All of these may affect body condition in wintering dabbling ducks, which in turn may affect an individual's survival and reproductive success. The aim of this study was to assess whether there have been morphometric changes in Mallard (Anas platyrhynchos) and Teal (Anas crecca) over the last 30 years at a major wintering site. Body mass and condition increased from the 1950s-1960s to the 2000s in both species. The increase in body mass amounted to as much as 11.7%, with no corresponding change in body size. Improved body condition was maintained from early to mid-winter, but then converged with historical values for late winter. Our interpretation is that increasingly benign ambient winter conditions permit ducks to maintain better energetic "safety margins" throughout winter, and that converging spring departure values may be related to evolutionary flight energetic optima. The observed changes are consistent with large-scale climate amelioration and local/regional habitat improvement (both anthropogenic).

  • 232.
    Guillemain, Matthieu
    et al.
    Frankrike.
    Pernollet, Claire A.
    Frankrike.
    Arzel, Céline
    Finland.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Eadie, John
    USA.
    Foraging, nutrition, and energetics of waterfowl: a European perspective2016In: 7th North American Duck Symposium: waterfowl ecology and adaptive management, 2016Conference paper (Refereed)
    Abstract [en]

    Much attention has historically been devoted to feeding ecology of waterfowl, providing an extensive research record for Europe and North America alike. However, research in this field has gradually followed different paths on the two continents. American scientists have adopted a more applied perspective, often aiming at assessing the extent to which food requirements of waterfowl can be fulfilled in different habitats, and how management of these can increase carrying capacity. As opposed to this "energetic" approach, European scientists have rather framed their studies in a "behavioral" perspective, using waterfowl as model species for more theoretical approaches to foraging ecology. Consequently, while North American research has most often been carried out at the scale of waterfowl populations, the individual bird has more frequently been the scale of study in Europe. We present three examples of such European studies: first, a detailed analysis of the trade-offs made by dabbling ducks between foraging and anti-predator vigilance, leading to divergent strategies to face gradual food depletion during the winter. Second, we do a flyway-scale analysis of duck foraging needs and behavior, from Mediterranean wintering grounds to breeding sites in the Boreal, and point out the main hurdles faced by these birds across their annual cycle. Such detailed European studies can provide useful parameter values to fuel modern agent-based models of habitat use and carrying capacity developed in North America, hence cross-fertilizing the approaches on the two continents. This is exactly what our third example is about; namely adapting the SWAMP model developed in California to better understand and predict the use of harvested rice fields by wintering ducks in southern France.

  • 233.
    Guillemain, Matthieu
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Pöysä, Hannu
    Finnish Game and Fisheries Research Institute, Joensuu Game and Fisheries Research.
    Fox, Anthony D.
    Thomas Eske Holm & Thomas Kjær Christensen, Department of Bioscience, Aarhus University.
    Arzel, Céline
    Department of Biology, Section of Ecology, University of Turku.
    Dessborn, Lisa
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Ekroos, Johan
    Centre for Environmental and Climate Research, Lund.
    Gunnarsson, Gunnar
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Eske Holm, Thomas
    Thomas Eske Holm & Thomas Kjær Christensen, Department of Bioscience, Aarhus University.
    Kjær Christensen, Thomas
    Thomas Eske Holm & Thomas Kjær Christensen, Department of Bioscience, Aarhus University.
    Lehikoinen, Aleksi
    Department of Biological and Environmental Sciences, University of Helsinki.
    Mitchell, Carl
    Wildfowl & Wetlands Trust, Slimbridge.
    Rintala, Jukka
    Finnish Game and Fisheries Research Institute, Helsinki.
    Pape Møller, Anders
    Laboratoire Ecologie Systématique et Evolution (UMR 8079), Université Paris-Sud XI, Orsay.
    Effects of climate change on European ducks: what do we know and what do we need to know?2013In: Wildlife Biology, ISSN 0909-6396, E-ISSN 1903-220X, Vol. 19, no 4, p. 404-419Article in journal (Refereed)
    Abstract [en]

    The consequences of climate change for bird populations have received much attention in recent decades, especially amongst cavity-nesting songbirds, yet little has been written on ducks (Anatidae) despite these being major elements of wetland diversity and important quarry species. This paper reviews the major known consequences of climate change for birds in general, and relates these to the limited information available specifically for ducks. Climate change can influence migration distance and phenology, potentially affecting patterns of mortality, as well as distribution and reproductive success in ducks. Studies addressing effects of climate change are, however, restricted to very few duck species, including mallardAnas platyrhynchos and common eider Somateria mollissima. Shifts in winter duck distributions have been observed, whereas the mismatch hypothesis (mistiming between the periods of peak energy requirements for young and the peak of seasonal food availability) has received limited support with regard to ducks. We propose a range of monitoring initiatives, including population surveys, breeding success monitoring schemes and individual duck marking, which should later be integrated through population modelling and adaptive management to fill these gaps.

  • 234. Guillmain, Matthieu
    et al.
    Elmberg, Johan
    Kristianstad University, School of Health and Society.
    Gauthier-Clerc, Michel
    Massez, Grégoire
    Hearn, Richard
    Simon, Géraldine
    Champagnon, Jocelyn
    Wintering dabbling ducks have become heavier: an effect of global warming or intensified game management practices?2009In: Abstracts, 2nd Pan-European Duck Symposium, 2009, p. 52-Conference paper (Refereed)
  • 235.
    Gunnarson, Gunnar
    et al.
    Kristianstad University, Department of Mathematics and Science.
    Elmberg, Johan
    Kristianstad University, Department of Mathematics and Science.
    Sjöberg, Kjell
    Department of Animal Ecology, Swedish University of Agricultural Sciences.
    Pöysä, Hannu
    Finnish Game and Fisheries Research Institute, Joensuu Game and Fisheries Research.
    Nummi, Petri
    Department of Applied Biology, University of Helsinki.
    Experimental evidence for density-dependent survival in mallard Anas platyrhynchos ducklings2006In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 149, no 2, p. 203-213Article in journal (Refereed)
    Abstract [en]

    It is unresolved to what extent waterfowl populations are regulated by density-dependent processes. By doing a 2-year crossover perturbation experiment on ten oligotrophic boreal lakes we addressed the hypothesis that breeding output is density dependent. Wing-clipped mallard (Anas platyrhynchos) hens were introduced with their own brood and then monitored for 24 days. Predicted responses were that per capita duckling and hen survival would be lower in high-density than in low-density treatments. Survival was evaluated by model fitting in program MARK. Density, year, and lake were used as main effects, while day after introduction, a weather harshness index, and presence of hens were covariates. Daily survival in ducklings was lower in the high-density treatment, but this effect was year dependent. The highest-ranking model for duckling survival also included a positive effect of duckling age and presence of hens, and a negative effect of harsh weather. Density did not affect female survival although there was a prominent year effect. The highest-ranking model for female survival also included negative effects of day after introduction and harsh weather. This is the first study to report density-dependent survival in experimentally introduced ducklings in a natural setting. Implications for population dynamics and management of harvested populations are far-reaching if such regulation occurs in some years, but not in others.

  • 236. Gunnarsson, Gunnar
    Mörbylånga hamn1992In: Fågellokaler på Öland, Färjestaden: Ölands ornitlogiska förening , 1992Chapter in book (Other (popular science, discussion, etc.))
  • 237.
    Gunnarsson, Gunnar
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Strandängarna i Kristianstads Vattenrike – hotade “hot spots”2015In: Forskningsmiljön Man & Biosphere Health: Högskolan Kristianstads miljöforskning i biosfärområde Kristianstads Vattenrike / [ed] Ingemar Jönsson, Kristianstad: Kristianstads kommun , 2015, p. 7-11Chapter in book (Other academic)
    Abstract [sv]

    På relativt kort tid har flera arter strandängsvadare minskat dramatiskt i Kristianstads Vattenrike. Pågående forskning bedrivs för att utröna om nedgångarna kan ha orsakats av faktorer längre ner i näringsväven. I speciellt fokus för forskningen är produktionen av vegetation och ryggradslösa djur.

  • 238.
    Gunnarsson, Gunnar
    Kristianstad University, Department of Mathematics and Science.
    Survival patterns and density-dependent processes in breeding mallards Anas platyrhynchos2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Measuring and assessing vital rates such as births and deaths are prerequisites for understanding population dynamics. Vital rates may be affected by the density of individuals, even though the importance of density dependence on population dynamics has been debated for a long time. The mallard Anas platyrhynchos is one of the foremost game species in the Holarctic, with millions of birds in hunters’ bags annually. Still, basic knowledge about regulation of mallards’ vital rates is poor, and experimental studies on this topic are rare.

    In this thesis I have studied survival patterns and density dependence in mallards breeding in Sweden and Finland. Long-term ringing data from both countries were analysed for mortality patterns and causation, as well as for e.g. survival rate estimation. Most of the studies were, though, experiments run over two years involving manipulations of the density of nests, broods and/or adults, in southern and northern Sweden, comprising different biotic regions. Common response variables were survival of nests, ducklings and hens, mainly analysed with program MARK.

    About 90% of the recovered mallards in Finland and Sweden were hunting kills. However, survival rates were high, ranging from 0.66 to 0.81 for most groups (sex*age). The generality of density dependence was evident since such processes were detected in all studies. Consequently, depredation rate was higher in high nest density compared to low nest density. Survival of ducklings was density-dependent in both boreal and nemoral biotic regions, with food limitation being evident in the former region but not in the latter. In spite of their generality, density-dependent patterns varied within as well between years, and for nest predation rates also between landscape types.

    The findings about density dependence in breeding mallards in this thesis are novel since they are based on experiments. They are potentially of general interest for management because they embrace a variety of lakes in two geographically distant areas, each being representative for large temperate areas in the northern hemisphere. Detection of density dependence at the local scale may be important at larger scales, too, following the principle of ‘ideal preemptive distribution’ in a source-sink dynamic system.

  • 239.
    Gunnarsson, Gunnar
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Vem äter vad på Håslövs ängar?: mätningar av betestryck med kopplingar till det ekologiska samhället2013Conference paper (Other (popular science, discussion, etc.))
  • 240.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, Department of Mathematics and Science.
    Elmberg, Johan
    Kristianstad University, Department of Mathematics and Science.
    Density-dependent nest predation: an experiment with simulated Mallard nests in contrasting landscapes2008In: Ibis, ISSN 0019-1019, E-ISSN 1474-919X, Vol. 150, no 2, p. 259-269Article in journal (Refereed)
    Abstract [en]

    Breeding success is a key element of animal population dynamics. In many taxa including birds, nest success, or the proportion of laid clutches that actually hatch, is mainly determined by predation. Previous research gives an inconsistent picture of the prevalence of density-dependent nest predation and one reason for this is the general lack of well-designed replicated experiments. Using simulated Mallard Anas platyrhynchos nests and a crossover design for 20 lakes in the nemoral and boreal biotic zones, we tested the predictions that nest survival is negatively density-dependent and that nest predation is higher in agricultural than in forested landscapes. Study day and daily abundance of waterfowl, other waterbirds, as well as avian predators were included as covariates in the analysis. Model fitting in program mark revealed a general negative effect of nest density on nest survival. In addition, nest survival rate was higher at forest lakes than at lakes in agricultural landscapes, irrespective of nest density. The only covariate producing model improvement was study day; older nests had higher survival rates than recently initiated ones. This is the first replicated lake-level experimental study showing that nest predation is density-dependent in waterfowl. The pattern was consistent between landscape types, implying that density-dependent nest predation may affect habitat choice and population dynamics over large parts of the Mallard's range.

  • 241.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Density-dependent nest predation in dabbling ducks2002Conference paper (Refereed)
  • 242.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Predation regulates the survival of mallard nests as revealed by an experiment in two landscape types2006Conference paper (Refereed)
    Abstract [en]

    Ecological theory frequently postulates that most animal species are subject to density-dependent mechanisms in some stage of the year or life. However, few avian studies have succeeded to give evidence for regulatory mechanisms by replicated experiments in natural habitats. Breeding success is to a great extent determined by conditions during the nesting period and the major cause of nesting failure is nest predation. In addition, predators may possibly regulate fluctuating populations and to test the hypothesis that nest survival is negatively density-dependent we conducted an experiment with manipulated densities of semi-natural Mallard nests and adult pairs using 32 small to medium sized lakes (~3-5 hectares) in southern Sweden during two nesting seasons (2003-2004). Predicting that predation rates are higher in open compared to more vegetated habitats, half of the lakes were in agricultural and the other half in forest landscapes. Using real Mallard eggs, nests were constructed in two densities; either 2 nests per lake (low density) or 8 nests per lake (high density). Model fitting in program MARK revealed that nest survival was negatively affected by nest density but not by pair density. Further, predation rates were much higher in agricultural landscapes than in forested. The effects of nest density and habitat were consistent in the two years. Covariates added to the model matrix revealed a negative effect of other waterfowl present on the lakes and a positive effect of study day. However, the number of avian predators observed at the lakes did not affect survival. Our experiment is the first to demonstrate density-dependent nest predation in Mallard. The consistency of the density effect between years and habitats shows that regulatory mechanisms may be truly significant for Mallard, possibly affecting population dynamics of the species.

  • 243.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Dessborn, Lisa
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Jonzén, Niclas
    Department of Theoretical Ecology, Lund University.
    Pöysä, Hannu
    Finnish Game and Fisheries Research Institute, Joensuu.
    Valkama, Jari
    Finnish Museum of Natural History, Helsinki.
    Survival estimates, mortality patterns, and population growth of Fennoscandian mallards Anas platyrhynchos2008In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 45, no 6, p. 483-495Article in journal (Refereed)
    Abstract [en]

    Long-term mallard capture-recapture data from Sweden and Finland were analyzed to describe temporal mortality patterns and reasons. We used program MARK and Seber models to estimate annual survival (S) and recovery (r) rates. Survival rates were used in a Monte Carlo simulation to evaluate the correspondence between observed and predicted annual population sizes of a Finnish sub-population. About 90% of recovered birds died from hunting. Most recoveries were from the hunting season, and more males than females were shot. Predation was the most common cause of natural mortality. Finnish capture-recapture data fitted best the global model in which survival and recovery vary with age and sex. Annual survival and recovery rates for adult and juvenile males and females were overlapping, ranging from 0.46 to 0.90 (survival) and 0.07 to 0.17 (recovery), whereas pulli had lower survival rates (0.21-0.42). Pulli that were successfully sexed at the time of ringing had higher recovery rates (female pulli: 0.23; male pulli: 0.32) than juveniles and adults. Density-dependent fledgling production was detected in the Finnish sub-population and was accounted for in the Monte Carlo simulation, which estimated predicted breeding population size quite well, although one of the observed annual values (2003) fell outside the 95% confidence limits.

  • 244.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Pöysä, Hannu
    Joensuu Game and Fisheries Research, Finnish Game and Fisheries Research Institute.
    Sjöberg, Kjell
    Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå.
    Dessborn, Lisa
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Arzel, Céline
    Section of Ecology, Department of Biology, Turku University.
    Density dependence in ducks: a review of the evidence2013In: European Journal of Wildlife Research, ISSN 1612-4642, E-ISSN 1439-0574, Vol. 59, no 3, p. 305-321Article in journal (Refereed)
    Abstract [en]

    Density dependence (DD) is a central concept in population ecology and in the management of harvested populations. For example, DD underpins the idea of additive versus compensatory mortality and is a tenet in the paradigm of resource limitation and regulation. Yet the prevalence and importance of DD remains disputed in most organisms, including ducks, which are focal in game management, conservation and zoonotic diseases. Based on 154 data entries from 54 studies in the peer-reviewed literature, we here synthesize and evaluate the prevalence of DD in breeding ducks in relation to (1) species and guild (dabbling versus diving ducks), (2) stage in the breeding cycle (nesting, duckling, recruitment) or, alternatively, in terms of population dynamics, (3) study type (descriptive/nonmanipulative versus experimental), (4) continent (Europe versus North America), (5) spatial level (wetland, landscape, regional, continental) and (6) biome (tundra, boreal, nemoral, prairie, mediterranean). One conclusion from this review is that it is difficult to find general patterns about the prevalence of DD unless data are broken down to subsets, for example, to stage or spatial level. With respect to stage, DD effects occur at all stages of the breeding cycle. During the nesting and duckling stages, the frequency of cases detecting versus not detecting DD is roughly the same. However, in cases referring to the recruitment stage, i.e. to survival of fledged ducks until 1 year old at the most, DD was the rule, suggesting that DD processes may operate mainly outside the breeding season. Further subdivision of data shows that spatial scale is important to the prevalence of DD in nesting ducks—rare on the wetland level and more common on higher spatial levels. In studies of population dynamics (i.e. based on time series data only), DD was more often found in diving than in dabbling ducks. This corroborates previous suggestions that dabbling ducks largely should be considered as r-selected species, in contrast to more K-selected diving ducks, which start to reproduce at an older age and often breed in more stable wetland environments where resources may be easier to track and populations thus often are closer to carrying capacity. However, the picture of DD in ducks is far from complete, and knowledge gaps for future studies to address include: (a) data from Russia, which holds a large part of the breeding ducks in the Northern hemisphere, (b) experimental studies on more species to separate density-dependent factors from other drivers of population change and to tease apart spatial and temporal interactions in the underlying processes, (c) time series analyses addressing population dynamics, especially from outside North America, (d) studies relating duck numbers to limiting resources, which arguably is the most relevant measure of density, (e) the timing of DD processes in relation to harvest and natural mortality.

  • 245.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Sjöberg, Kjell
    SLU.
    Pöysä, Hannu
    Finland.
    Nummi, Petri
    Finland.
    Experimental evidence for density-dependent breeding success in mallards2005Conference paper (Refereed)
    Abstract [en]

    It is unresolved to what extent waterfowl populations are regulated by density-dependent pro cesses. By doing a 2-year crossover perturbation exper iment on ten oligotrophic boreal lakes we addressed the hypothesis that breeding output is density depen dent. Wing-clipped mallard (Anas platyrhynchos) hens were introduced with their own brood and then moni tored for 24 days. Predicted responses were that per capita duckling and hen survival would be lower in high-density than in low-density treatments. Survival was evaluated by model fitting in program MARK. Density, year, and lake were used as main effects, while day after introduction, a weather harshness index, and presence of hens were covariates. Daily survival in ducklings was lower in the high-density treatment, but this effect was year dependent. The highest-ranking model for duckling survival also included a positive effect of duckling age and presence of hens, and a nega tive effect of harsh weather. Density did not affect female survival although there was a prominent year effect. The highest-ranking model for female survival also included negative effects of day after introduction and harsh weather. This is the first study to report den sity-dependent survival in experimentally introduced ducklings in a natural setting. Implications for population dynamics and management of harvested populations are far-reaching if such regulation occurs in some years, but not in others.

  • 246.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Sjöberg, Kjell
    SLU.
    Pöysä, Hannu
    Finland.
    Nummi, Petri
    Finland.
    Food limits survival in breeding mallards2003In: Integrating wildlife with people, 10th International Perdix Symposium, Braga, Portugal, September 1st-6th 2003: abstracts and contributing authors, Braga: International Union of Game Biologists , 2003Conference paper (Refereed)
  • 247.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Sjöberg, Kjell
    SLU.
    Pöysä, Hannu
    Finland.
    Nummi, Petri
    Finland.
    Food limits survival of breeding boreal mallards Anas platyrhynchos2003Conference paper (Refereed)
    Abstract [en]

    During the breeding period dabbling ducks (Anas sp.), and especially newly hatched ducklings, face heavy mortality. The reasons are not clear, but suggested factors contributing are scarce food, predation, chilling and disease. We highlighted the question why many of the boreal lakes in Scandinavia are without breeding ducks and why mortality is considerable during brood period. In an experimental study in 2002 we hypothesized food being a major factor deciding duck survival during breeding. One wing-clipped hen mallard with her own newly hatched brood (10 ducklings) was introduced onto each of 10 lakes. Food was added ad libitum at 5 of these lakes (experimental lakes), whereas the other five lakes (controls) did not get any extra food added. Survival of hens, broods as well as each individual duckling was monitored regularly until 24 days after introduction. At all three levels (i.e. duckling, brood and adult), survival was significantly higher on lakes with food added than on control lakes, although the difference was most pronounced on the duckling level. Direct consequences (i.e. dying from starvation) as well as indirect (e.g. undernourished individuals being more easily taken by predators) may both explain this pattern. Our results clearly show that food is a major limiting factor on mallard survival in this environment. Also, our results may explain why many boreal lakes in Scandinavia do not have any breeding waterfowl at all. It seems likely that such lakes are too poor to raise broods and even to sustain adults.

  • 248.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, Department of Mathematics and Science.
    Elmberg, Johan
    Kristianstad University, Department of Mathematics and Science.
    Sjöberg, Kjell
    Department of Animal Ecology, Swedish University of Agricultural Sciences, Umeå.
    Pöysä, Hannu
    Finnish Game and Fisheries Research Institute, Joensuu Game and Fisheries Research.
    Nummi, Petri
    Department of Applied Biology, University of Helsinki.
    Why are there so many empty lakes?: food limits survival of mallard ducklings2004In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 82, no 11, p. 1698-1703Article in journal (Refereed)
    Abstract [en]

    Food is an important factor affecting survival in many bird species, but this relationship has rarely been explored experimentally with respect to reproductive output of precocial birds. In a field experiment we tested the hypothesis that food abundance limits reproductive output in breeding dabbling ducks. Onto 10 oligotrophic lakes in northern Sweden we introduced one wing-clipped female mallard (Anas platyrhynchos L., 1758) and a brood of 10 newly hatched ducklings, and survival was monitored for 24 days. Food was added ad libitum at five of the lakes, but not at the other five. Duckling survival was best modelled to include a treatment effect, with higher survival on lakes with food added, and a negative effect of harsh weather. As expected, duckling survival increased nonlinearly with age. Only one female remained on control lakes after 24 days, whereas four remained on lakes with food added. This is the first experimental demonstration that food may limit survival and reproductive output in breeding precocial birds. We argue that food limitation may be one reason why duckling mortality is high and why many lakes throughout the Holarctic have no breeding dabbling ducks.

  • 249.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man and Biosphere Health (MABH).
    Waldenström, Jonas
    Section for Zoonotic Ecology and Epidemiology, School of Natural Sciences, Linnaeus University, Kalmar.
    Trends in body mass of ducks over time: the hypotheses in Guillemain et al. revisited2011In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 40, no 3, p. 338-340Article in journal (Refereed)
  • 250.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University, School of Teacher Education.
    Elmberg, Johan
    Kristianstad University, School of Teacher Education.
    Waldenström, Jonas
    Olsen, Björn
    Änderna, influensan och jakten2010In: Svensk jakt: Svenska jägareförbundets tidskrift, ISSN 0039-6583, no 6, p. 74-75Article in journal (Other (popular science, discussion, etc.))
2345678 201 - 250 of 539
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