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Söderquist, P., Dessborn, L., Djerf, H., Elmberg, J., Gunnarsson, G. & Holopainen, S. (2021). Effects of released farmed mallards on species richness of breeding waterbirds and amphibians in natural, restored and constructed wetlands. Wildlife Biology, 2021, 1-9, Article ID wlb.00846.
Åpne denne publikasjonen i ny fane eller vindu >>Effects of released farmed mallards on species richness of breeding waterbirds and amphibians in natural, restored and constructed wetlands
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2021 (engelsk)Inngår i: Wildlife Biology, ISSN 0909-6396, E-ISSN 1903-220X, Vol. 2021, s. 1-9, artikkel-id wlb.00846Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Common practices in current game management are wetland restoration and creation, as well as releases of quarry species. We studied the impact of releases of mallard ducklings on species richness of wild waterbirds and amphibians on three types of wetlands: natural, constructed and restored. Data on species richness, macrophyte cover and water characteristics (total phosphorous and pH) were collected at 32 sites in an agricultural landscape in southern Sweden. In total, 14 species of waterbirds were recorded, ranging from zero to seven per wetland and survey. Amphibians were present in 24 of the 32 wetlands; in total five species were found, ranging from zero to three per wetland. By using generalized linear modelling we found that wetland type best predicted waterbird species richness. Constructed wetlands had significantly more waterbird species, regardless of whether they were used for mallard releases or not. There were breeding amphibians in 62% of natural, 100% of restored and 77% of constructed wetlands. Breeding amphibians were present in 84% of wetlands without, and in 62% of wetlands with releases. However, included variables did not explain amphibian species richness in the wetlands. Releasing large numbers of mallards on a wetland and providing food ad libitum is likely to affect water quality, nutrient availability and predation pressure. Indeed, phosphorous levels were significantly higher in release wetlands, but no differences were found between wetland types.This means that mallard releases may increase nutrient loads in environments that are already eutrophied. However, in our study system releases did not influence species richness of waterbirds and amphibians locally. Constructing wetlands for mallard releases can thus have positive local effects on species richness.

Emneord
Species richness, Constructed wetlands, biodiversity, created wetlands, eutrophication, farmed, hand-reared, restocking, supplementary feeding, waterbirds, waterfowl
HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-22302 (URN)10.2981/wlb.00846 (DOI)
Forskningsfinansiär
Swedish Environmental Protection Agency, 16/83 NV-00695-17
Tilgjengelig fra: 2021-08-17 Laget: 2021-08-17 Sist oppdatert: 2021-08-17bibliografisk kontrollert
Söderquist, P., Gunnarsson, G., Elmberg, J. & Dessborn, L. (2021). Survival of wild and farmed-released mallards: the Swedish example. European Journal of Wildlife Research, 67(2)
Åpne denne publikasjonen i ny fane eller vindu >>Survival of wild and farmed-released mallards: the Swedish example
2021 (engelsk)Inngår i: European Journal of Wildlife Research, ISSN 1612-4642, E-ISSN 1439-0574, Vol. 67, nr 2Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

More than three million farmed mallards are released annually for hunting purposes in Europe. The ecological impact of these releases depends on how many birds survive to join the wild breeding population. We estimated annual survival in farmed-released and wild-caught Swedish mallards, using mark-recapture data. In 2011–2018, we ringed 13,533 farmed ducklings before release (26.5% recovered). Most recoveries were birds shot at the release site, while only about 4% were found >3 km away. In 2002–2018, 19,820 wild mallards were ringed in Sweden, yielding 1369 (6.9%) recoveries. Like in farmed-released birds, most recoveries were by hunting, but 91.1% of recovered wild mallards were >3 km away from the ringing site. Annual survival rate in farmed-released mallards (ringed as pulli) was 0.02. In wild mallards (ringed as fledged or fully grown), annual survival was lower in females (0.64) than in males (0.71). At two sites in 2018, farmed ducklings were released in two batches 3 weeks apart to study the effect of early versus late release date, while controlling for body condition (BCI). Ducklings released early had a higher BCI and were recovered earlier (lower longevity) than those released late. Individual BCI and longevity were not correlated in recovered ducklings. Based on our estimate of annual survival in farmed-released mallards, a substantial number, i.e., 5000 (95% CI, 3040–6960), join the wild population annually. Despite being fed, a large proportion of released ducklings does not survive until the hunting season. Early releases may maximize pre-hunting survival. Repeated releases may prolong hunting opportunities and increase hunting bags.

Emneord
Body condition index, captive reared, hunting, restocking, ringing, recoveries
HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-21639 (URN)10.1007/s10344-021-01465-7 (DOI)000615555400001 ()
Tilgjengelig fra: 2021-02-08 Laget: 2021-02-08 Sist oppdatert: 2021-03-04bibliografisk kontrollert
Olsson, V., Söderquist, P., Olsson, C. & Birch, K. (2019). Vilda matfåglar: ekologi och gastronomi. In: : . Paper presented at BIOSFÄR 2019 Forskningskonferens i Vattenriket.
Åpne denne publikasjonen i ny fane eller vindu >>Vilda matfåglar: ekologi och gastronomi
2019 (svensk)Konferansepaper, Oral presentation only (Annet (populærvitenskap, debatt, mm))
HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-20226 (URN)
Konferanse
BIOSFÄR 2019 Forskningskonferens i Vattenriket
Tilgjengelig fra: 2020-01-03 Laget: 2020-01-03 Sist oppdatert: 2020-01-09bibliografisk kontrollert
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)
Åpne denne publikasjonen i ny fane eller vindu >>Admixture between released and wild game birds: a changing genetic landscape in European mallards (Anas platyrhynchos)
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2017 (engelsk)Inngår i: European Biophysics Journal, ISSN 0175-7571, E-ISSN 1432-1017, Vol. 63, nr 6Artikkel i tidsskrift (Fagfellevurdert) 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.

Emneord
Cryptic introgression; Hand-reared; Hybridization; Restocking; SNP; Wildlife management
HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-17669 (URN)10.1007/s10344-017-1156-8 (DOI)000418192400008 ()
Tilgjengelig fra: 2017-12-05 Laget: 2017-12-05 Sist oppdatert: 2018-01-09bibliografisk kontrollert
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.
Åpne denne publikasjonen i ny fane eller vindu >>Farmed European mallards are genetically different and cause introgression in the wild population following releases
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2016 (engelsk)Konferansepaper, Poster (with or without abstract) (Fagfellevurdert)
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.

HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-15340 (URN)
Konferanse
The 7th North American Duck Symposium (NADS7), Annapolis, Maryland, 1-5 February 2016
Tilgjengelig fra: 2016-03-18 Laget: 2016-03-18 Sist oppdatert: 2017-05-08bibliografisk kontrollert
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
Åpne denne publikasjonen i ny fane eller vindu >>Current and potential threats to Nordic duck populations - a horizon scanning exercise
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2015 (engelsk)Inngår i: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 52, nr 4, s. 193-220Artikkel i tidsskrift (Fagfellevurdert) 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.

Emneord
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
HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-14572 (URN)000359460900001 ()
Tilgjengelig fra: 2015-09-16 Laget: 2015-09-16 Sist oppdatert: 2017-12-04bibliografisk kontrollert
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.
Åpne denne publikasjonen i ny fane eller vindu >>Freigelassenes Federwild führt zu kontinent-weiter genetischer Introgression: die sich ändernde genetische Landschaft der Stockente Anas platyrhynchos in Europa
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2015 (tysk)Konferansepaper, Oral presentation with published abstract (Fagfellevurdert)
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.

HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-16065 (URN)
Konferanse
148. DO-G (Deutsche Ornithologen Gesellschaft) Jahresversammlung 2015 in Konstanz 30. September bis 05. Oktober 2015, Campus der Universität Konstanz
Tilgjengelig fra: 2016-09-22 Laget: 2016-09-22 Sist oppdatert: 2016-09-22bibliografisk kontrollert
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.
Åpne denne publikasjonen i ny fane eller vindu >>Freigelassenes Federwild führt zu kontinent-weiter genetischer Introgression: die sich ändernde genetische Landschaft der Stockente (Anas platyrhynchos) in Europa
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2015 (tysk)Konferansepaper, Oral presentation with published abstract (Fagfellevurdert)
HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-15062 (URN)
Konferanse
148th Annual Meeting of the German Ornithologists´ Society
Tilgjengelig fra: 2015-11-30 Laget: 2015-11-30 Sist oppdatert: 2017-05-03bibliografisk kontrollert
Söderquist, P. (2015). Large-scale releases of native species: the mallard as a predictive model system. (Doctoral dissertation). Umeå: Sveriges Lantbruksuniversitet
Åpne denne publikasjonen i ny fane eller vindu >>Large-scale releases of native species: the mallard as a predictive model system
2015 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
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.

sted, utgiver, år, opplag, sider
Umeå: Sveriges Lantbruksuniversitet, 2015
Serie
Acta Universitatis agriculturae Sueciae, ISSN 1652-6880 ; 2015:25
HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-13751 (URN)978-91-576-8248-2 (ISBN)978-91-576-8249-9 (ISBN)
Tilgjengelig fra: 2015-03-30 Laget: 2015-03-30 Sist oppdatert: 2018-01-11bibliografisk kontrollert
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..
Åpne denne publikasjonen i ny fane eller vindu >>Released game birds cause introgression in European mallard
Vise andre…
2015 (engelsk)Konferansepaper, Poster (with or without abstract) (Fagfellevurdert)
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.

HSV kategori
Identifikatorer
urn:nbn:se:hkr:diva-13803 (URN)
Konferanse
The fourth Pan-European Duck Symposium, Hanko/Hangö, Finland, April 7-11, 2015.
Forskningsfinansiär
Swedish Environmental Protection Agency
Tilgjengelig fra: 2015-04-14 Laget: 2015-04-14 Sist oppdatert: 2017-05-03bibliografisk kontrollert
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-1212-6607