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Söderquist, Pär
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Publications (10 of 21) Show all publications
Söderquist, P., Elmberg, J., Gunnarsson, G., Thulin, C.-G., Champagnon, J., Guillemain, M., . . . R. H. S., K. (2017). Admixture between released and wild game birds: a changing genetic landscape in European mallards (Anas platyrhynchos). European Biophysics Journal, 63(6)
Open this publication in new window or tab >>Admixture between released and wild game birds: a changing genetic landscape in European mallards (Anas platyrhynchos)
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2017 (English)In: European Biophysics Journal, ISSN 0175-7571, E-ISSN 1432-1017, Vol. 63, no 6Article in journal (Refereed) Published
Abstract [en]

Disruption of naturally evolved spatial patterns of genetic variation and local adaptations is a growing concern in wildlife management and conservation. During the last decade, releases of native taxa with potentially non-native genotypes have received increased attention. This has mostly concerned conservation programs, but releases are also widely carried out to boost harvest opportunities. The mallard, Anas platyrhynchos, is one of few terrestrial migratory vertebrates subjected to large-scale releases for hunting purposes. It is the most numerous and widespread duck in the world, yet each year more than three million farmed mallard ducklings are released into the wild in the European Union alone to increase the harvestable population. This study aimed to determine the genetic effects of such large-scale releases of a native species, specifically if wild and released farmed mallards differ genetically among subpopulations in Europe, if there are signs of admixture between the two groups, if the genetic structure of the wild mallard population has changed since large-scale releases began in the 1970s, and if the current data matches global patterns across the Northern hemisphere. We used Bayesian clustering (Structure software) and Discriminant Analysis of Principal Components (DAPC) to analyze the genetic structure of historical and present-day wild (n = 171 and n = 209, respectively) as well as farmed (n = 211) mallards from six European countries as inferred by 360 single-nucleotide polymorphisms (SNPs). Both methods showed a clear genetic differentiation between wild and farmed mallards. Admixed individuals were found in the present-day wild population, implicating introgression of farmed genotypes into wild mallards despite low survival among released farmed mallards. Such cryptic introgression would alter the genetic composition of wild populations and may have unknown long-term consequences for conservation.

Keywords
Cryptic introgression; Hand-reared; Hybridization; Restocking; SNP; Wildlife management
National Category
Natural Sciences
Identifiers
urn:nbn:se:hkr:diva-17669 (URN)10.1007/s10344-017-1156-8 (DOI)000418192400008 ()
Available from: 2017-12-05 Created: 2017-12-05 Last updated: 2018-01-09Bibliographically approved
Elmberg, J., Söderquist, P., Gunnarsson, G., Thulin, C.-G., Champagnon, J., Guillemain, M., . . . Kraus, R. H. (2016). Farmed European mallards are genetically different and cause introgression in the wild population following releases. In: : . Paper presented at The 7th North American Duck Symposium (NADS7), Annapolis, Maryland, 1-5 February 2016.
Open this publication in new window or tab >>Farmed European mallards are genetically different and cause introgression in the wild population following releases
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2016 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

The practice of restocking already viable populations to increase harvest potential has since long been common in forestry, fisheries and wildlife management. The potential risks of restocking native species have long been overshadowed by the related issue of invasive alien species. However, during the last decade releases of native species with potentially non-native genome have received more attention. A suitable model to study genetic effects of large-scale releases of native species is the Mallard Anas platyrhynchos, being the most widespread duck in the world, largely migratory, and an important quarry species. More than 3 million unfledged hatchlings are released each year around Europe to increase local harvest. The aims of this study were to determine if wild and released farmed Mallards differ genetically, if there are signs of previous or ongoing introgression between wild and farmed birds, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in Europe in the 1970s. Using 360 Single Nucleotide Polymorphisms (SNPs) we found that the genetic structure differed among historical wild, present-day wild, and farmed Mallards in Europe. We also found signs of introgression in the wild Mallard population, that is, individuals with a genetic background of farmed stock are part of the present free-living population. Although only a small proportion of the released Mallards appears to survive to merge with the free-living breeding population, their numbers are still so large that the genetic impact may have significance for the wild population in terms of individual survival and longterm fitness.

National Category
Ecology Genetics
Identifiers
urn:nbn:se:hkr:diva-15340 (URN)
Conference
The 7th North American Duck Symposium (NADS7), Annapolis, Maryland, 1-5 February 2016
Available from: 2016-03-18 Created: 2016-03-18 Last updated: 2017-05-08Bibliographically approved
Fox, A. D., Jonsson, J. E., Aarvak, T., Bregnballe, T., Christensen, T. K., Clausen, K. K., . . . Therkildsen, O. R. (2015). Current and potential threats to Nordic duck populations - a horizon scanning exercise. Annales Zoologici Fennici, 52(4), 193-220
Open this publication in new window or tab >>Current and potential threats to Nordic duck populations - a horizon scanning exercise
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2015 (English)In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 52, no 4, p. 193-220Article in journal (Refereed) Published
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.

Keywords
mallards anas-platyrhynchos, eiders somateria-mollissima, sea-level rise, goldeneye bucephala-clangula, conspecific nest parasitism, annual breeding success, avian influenza-virus, valdez oil-spill, Dutch Wadden sea, climate-change
National Category
Ecology
Identifiers
urn:nbn:se:hkr:diva-14572 (URN)000359460900001 ()
Available from: 2015-09-16 Created: 2015-09-16 Last updated: 2017-12-04Bibliographically approved
Kraus, R., Söderquist, P., Gunnarsson, G., Thulin, C.-G., Champagnon, J., Guillemain, M., . . . Elmberg, J. (2015). Freigelassenes Federwild führt zu kontinent-weiter genetischer Introgression: die sich ändernde genetische Landschaft der Stockente Anas platyrhynchos in Europa. In: : . Paper presented at 148. DO-G (Deutsche Ornithologen Gesellschaft) Jahresversammlung 2015 in Konstanz 30. September bis 05. Oktober 2015, Campus der Universität Konstanz.
Open this publication in new window or tab >>Freigelassenes Federwild führt zu kontinent-weiter genetischer Introgression: die sich ändernde genetische Landschaft der Stockente Anas platyrhynchos in Europa
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2015 (German)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [de]

Es ist eine seit langem übliche Praxis in Forstwirtschaft, Fischerei und allgemeinem Wildtiermanagement, Wildtierbestände gezielt aufzustocken. In den letzten ca. zehn Jahren haben aber solche Programme Aufmerksamkeit erregt, in denen lokale Bestände von Tierarten mit Individuen der gleichen Art, aber aus anderen Regionen und damit potentiell nicht-nativen Genomen aufgestockt wurden. Die Stockente Anas platyrhynchos ist ein geeignetes Modell um die genetischen Effekte solcher großskaligen Freisetzungen auf den einheimischen Genpool zu untersuchen, weil sie die am weitesten verbreitete und zahlreichste Entenart der Welt ist, über weite Strecken migrieren kann und gleichzeitig global das wichtigste Federwild darstellt. In vielen europäischen Ländern wird die Stockente seit etwa den frühen 1970er Jahren auch auf speziellen Farmen gezüchtet und zu Jagdzwecken ausgesetzt. So gehen aktuelle Schätzungen davon aus, dass jährlich etwa drei Millionen junge Enten nur zum Zweck der Aufstockung zur Jagd an europäischen Gewässern ausgesetzt werden. Die Ziele unserer Studie waren herauszufinden, ob sich Enten von Farmpopulationen genetisch von wilden Enten unterscheiden lassen, ob es Anzeichen früherer oder anhaltender genetischer Introgression zwischen diesen beiden Gruppen gibt und ob sich die genetische Struktur der wilden Entenpopulationen seit der großskaligen Entenaufstockung verändert hat. Dazu verwendeten wir 360 SNP Marker (Single Nucleotide Polymorhpism) um die genetische Struktur von historischen wilden Stockenten (Museumsproben), zeitgenössischen wilden Stockenten und Farm-Enten zu vergleichen (N = 591). Wir fanden klare genetische Unterschiede zwischen wilden Stockenten und Farm-Enten in mehreren Ländern Europas. Ebenfalls konnten wir genetische Introgression von Genen der Farm-Enten in die wilde Stockentenpopulation zeigen. Die Vermischung scheint bisher zwar messbar aber noch gering zu sein, da auf Farmen gezüchtete Stockenten in der Wildnis geringe Überlebensraten aufweisen. Dennoch sollte die weitere Einkreuzung von Farm-Enten in die wilden Stockentenpopulationen so gering wie möglich gehalten werden, da durch anhaltende genetische Introgression möglicherweise in Zukunft lokale Anpassungen der wilden Stockenten geschwächt werden, was eine Bedrohung dieser Bestände darstellen könnte.

National Category
Biological Sciences
Identifiers
urn:nbn:se:hkr:diva-16065 (URN)
Conference
148. DO-G (Deutsche Ornithologen Gesellschaft) Jahresversammlung 2015 in Konstanz 30. September bis 05. Oktober 2015, Campus der Universität Konstanz
Available from: 2016-09-22 Created: 2016-09-22 Last updated: 2016-09-22Bibliographically approved
Kraus, R. H., Söderquist, P., Gunnarsson, G., Thulin, C.-G., Champagnon, J., Guillemain, M., . . . Elmberg, J. (2015). Freigelassenes Federwild führt zu kontinent-weiter genetischer Introgression: die sich ändernde genetische Landschaft der Stockente (Anas platyrhynchos) in Europa. In: : . Paper presented at 148th Annual Meeting of the German Ornithologists´ Society.
Open this publication in new window or tab >>Freigelassenes Federwild führt zu kontinent-weiter genetischer Introgression: die sich ändernde genetische Landschaft der Stockente (Anas platyrhynchos) in Europa
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2015 (German)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Genetics
Identifiers
urn:nbn:se:hkr:diva-15062 (URN)
Conference
148th Annual Meeting of the German Ornithologists´ Society
Available from: 2015-11-30 Created: 2015-11-30 Last updated: 2017-05-03Bibliographically approved
Söderquist, P. (2015). Large-scale releases of native species: the mallard as a predictive model system. (Doctoral dissertation). Umeå: Sveriges Lantbruksuniversitet
Open this publication in new window or tab >>Large-scale releases of native species: the mallard as a predictive model system
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Human alteration of natural systems, and its consequences are of great concern and the impact on global ecosystems is one of the biggest threats that biodiversity stands before. Translocations of invasive species, as well as intraspecific contingents with non-native genotypes, whether they are deliberate or unintentional, are one such alteration and its consequences are continuously being assessed. The mallard (Anas platyrhynchos) is the most numerous and widespread duck in the world and a flagship in wetland conservation. It is also an important game species which is heavily restocked for hunting purposes, especially in Europe where over three million ducklings are released every year. Because of its hunted status, its abundance, and the number of released individuals, it can serve as a model species to study effects of releases, both for conservation and restocking for hunting, on wild populations. In this thesis the status of the mallard was assessed in the Nordic countries and the effects of releases on the wild populations were studied by mining historical ringing data, comparing morphology of present-day wild, farmed, and historical mallards, and analyzing phylogeography of wild and farmed mallards in Europe. The status of the mallard population in the Nordic countries are generally good, however, a joint effort of European countries is needed to monitor and manage the population. A significant difference between wild and farmed mallards concerning longevity, migration, bill morphology and genetic structure was also found, together with signs of cryptic introgression of farmed genotypes in the wild population with potential fitness reduction as a result. The effect is however limited by that only a fraction of released farmed mallards reach the breeding season due to low survival. A natural captive environment is crucial to keep individuals wild-like with high survival rates after release. However, with an introgression of potentially maladapted farmed genotypes leading to a reduction in fitness, a low survival of released mallards would favor the wild population. A legislative change regarding obligation to report numbers, provenance, and release sites of farmed mallard should be considered, together with practical solutions of ringing and genetic monitoring of released mallards.

Place, publisher, year, edition, pages
Umeå: Sveriges Lantbruksuniversitet, 2015
Series
Acta Universitatis agriculturae Sueciae, ISSN 1652-6880 ; 2015:25
National Category
Zoology Fish and Wildlife Management
Identifiers
urn:nbn:se:hkr:diva-13751 (URN)978-91-576-8248-2 (ISBN)978-91-576-8249-9 (ISBN)
Available from: 2015-03-30 Created: 2015-03-30 Last updated: 2018-01-11Bibliographically approved
Söderquist, P., Elmberg, J., Gunnarsson, G., Thulin, C.-G., Champagnon, J., Guillemain, M., . . . Kraus, R. (2015). Released game birds cause introgression in European mallard. In: : . Paper presented at The fourth Pan-European Duck Symposium, Hanko/Hangö, Finland, April 7-11, 2015..
Open this publication in new window or tab >>Released game birds cause introgression in European mallard
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2015 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

The practice of restocking already viable populations to improve harvest has since long been common in forestry, fisheries and wildlife management. The potential risks with restocking of native species has for a long time been overshadowed by the related issue of invasive species. However, during the last decade releases of native species with a potential non-native genome have attained more attention. A suitable model species for studying genetic effects of large-scale releases of a native species is the Mallard, Anas platyrhynchos; it is the most widespread duck in the world, it is a migrating species, and an important game bird. In several European countries it is also farmed and released to increase the harvestable population, and more than 3 million unfledged hatchlings are released each year around Europe. The aims of this study were to determine if wild and released farmed Mallards differed genetically among subpopulations in Europe, if there are signs of previous or ongoing introgression between wild and farmed Mallards, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in the 1970s. We used 360 Single Nucleotide Polymorphisms (SNPs) to analyze the genetic structure of historical wild, present-day wild, and farmed Mallards. We found a clear genetic difference between wild and farmed Mallards in Europe. We also found signs of introgression of farmed genes in the wild Mallard population, however, the rate of hybridization is probably minor due to low survival of released farmed Mallards and a change of the wild population since the start of large-scale releases is therefore limited. A low level of hybridization between farmed and wild Mallard is desired as introgressed genes may be detrimental for wild Mallards, and efforts to increase survival of farmed Mallards should therefore not be encouraged.

National Category
Ecology Genetics
Identifiers
urn:nbn:se:hkr:diva-13803 (URN)
Conference
The fourth Pan-European Duck Symposium, Hanko/Hangö, Finland, April 7-11, 2015.
Funder
Swedish Environmental Protection Agency
Available from: 2015-04-14 Created: 2015-04-14 Last updated: 2017-05-03Bibliographically approved
Söderquist, P., Elmberg, J., Gunnarsson, G., Thulin, C.-G., Champagnon, J., Guillemain, M., . . . Kraus, R. (2015). Released gamebrds cause introgression in European mallard. In: 4th Pan-European Duck Symposium, Hangö, Finland: . Paper presented at 4th Pan-European Duck Symposium, Hangö, Finland, 7-11/4, 2015 (pp. 75).
Open this publication in new window or tab >>Released gamebrds cause introgression in European mallard
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2015 (English)In: 4th Pan-European Duck Symposium, Hangö, Finland, 2015, p. 75-Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

The practice of restocking already viable populations to improve harvest has since long been common in forestry, fisheries and wildlife management. The potential risks with restocking of native species has for a long time been overshadowed by the related issue of invasive species. However, during the last decade releases of native species with a potential non-native genome have attained more attention. A suitable model species for studying genetic effects of large-scale releases of a native species is the Mallard, Anas platyrhynchos; it is the most widespread duck in the world, it is a migrating species, and an important game bird. In several European countries it is also farmed and released to increase the harvestable population, and more than 3 million unfledged hatchlings are released each year around Europe. The aims of this study were to determine if wild and released farmed Mallards differed genetically among subpopulations in Europe, if there are signs of previous or ongoing introgression between wild and farmed Mallards, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in the 1970s. We used 360 Single Nucleotide Polymorphisms (SNPs) to analyze the genetic structure of historical wild, present-day wild, and farmed Mallards. We found a clear genetic difference between wild and farmed Mallards in Europe. We also found signs of introgression of farmed genes in the wild Mallard population, however, the rate of hybridization is probably minor due to low survival of released farmed Mallards and a change of the wild population since the start of large-scale releases is therefore limited. A low level of hybridization between farmed and wild Mallard is desired as introgressed genes may be detrimental for wild Mallards, and efforts to increase survival of farmed Mallards should therefore not be encouraged.

National Category
Biological Sciences
Identifiers
urn:nbn:se:hkr:diva-16073 (URN)
Conference
4th Pan-European Duck Symposium, Hangö, Finland, 7-11/4, 2015
Available from: 2016-09-26 Created: 2016-09-26 Last updated: 2017-05-03Bibliographically approved
Söderquist, P., Norrström, J., Elmberg, J., Guillemain, M. & Gunnarsson, G. (2015). Wild mallards have more "goose-like" bills than their ancestors. In: 4th Pan-European Duck Symposium, Hangö, Finland, 7-11/4, 2015: . Paper presented at 4th Pan-European Duck Symposium, Hangö, Finland, 7-11/4, 2015 (pp. 38).
Open this publication in new window or tab >>Wild mallards have more "goose-like" bills than their ancestors
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2015 (English)In: 4th Pan-European Duck Symposium, Hangö, Finland, 7-11/4, 2015, 2015, p. 38-Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Wild populations of the world’s most common dabbling duck, the Mallard (Anas platyrhynchos), run the risk of genetic introgression by farmed conspecifics released for hunting purposes. We tested whether bill morphology of free-living birds has changed since large-scale releases of farmed Mallards started. Three groups of Mallards from Sweden, Norway and Finland were compared: historical wild (before large-scale releases started), present-day wild, and present-day farmed. Higher density of bill lamellae was observed in historical wild Mallards (only males). Farmed Mallards had wider bills than present-day and historical wild ones. Present-day wild and farmed Mallards also had higher and shorter bills than historical wild Mallards. Present-day Mallards thus tend to have more ‘‘goose-like’’ bills (wider, higher, and shorter) than their ancestors. Our study suggests that surviving released Mallards affect morphological traits in wild population by introgression. We discuss how such anthropogenic impact may lead to a maladapted and genetically compromised wild Mallard population. Our study system has bearing on other taxa where large-scale releases of conspecifics with ‘alien genes’ may cause a cryptic invasive process that nevertheless has fitness consequences for individual birds.

National Category
Biological Sciences
Identifiers
urn:nbn:se:hkr:diva-16072 (URN)
Conference
4th Pan-European Duck Symposium, Hangö, Finland, 7-11/4, 2015
Available from: 2016-09-26 Created: 2016-09-26 Last updated: 2017-05-08Bibliographically approved
Söderquist, P., Norrström, J., Elmberg, J., Guillemain, M. & Gunnarsson, G. (2015). Wild Mallards have more ”goose-like” bills than their ancestors. In: : . Paper presented at The fourth Pan-European Duck Symposium, Hanko/Hangö, Finland, April 7-11, 2015..
Open this publication in new window or tab >>Wild Mallards have more ”goose-like” bills than their ancestors
Show others...
2015 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Wild populations of the world’s most common dabbling duck, the Mallard (Anas platyrhynchos), run the risk of genetic introgression by farmed conspecifics released for hunting purposes. We tested whether bill morphology of free-living birds has changed since large-scale releases of farmed Mallards started. Three groups of Mallards from Sweden, Norway and Finland were compared: historical wild (before large-scale releases started), present-day wild, and present-day farmed. Higher density of bill lamellae was observed in historical wild Mallards (only males). Farmed Mallards had wider bills than present-day and historical wild ones. Present-day wild and farmed Mallards also had higher and shorter bills than historical wild Mallards. Present-day Mallards thus tend to have more ‘‘goose-like’’ bills (wider, higher, and shorter) than their ancestors. Our study suggests that surviving released Mallards affect morphological traits in wild population by introgression. We discuss how such anthropogenic impact may lead to a maladapted and genetically compromised wild Mallard population. Our study system has bearing on other taxa where large-scale releases of conspecifics with ‘alien genes’ may cause a cryptic invasive process that nevertheless has fitness consequences for individual birds.

National Category
Ecology
Identifiers
urn:nbn:se:hkr:diva-13802 (URN)
Conference
The fourth Pan-European Duck Symposium, Hanko/Hangö, Finland, April 7-11, 2015.
Funder
Swedish Environmental Protection Agency
Available from: 2015-04-14 Created: 2015-04-14 Last updated: 2017-05-03Bibliographically approved
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