| 1. |
- Arzel, Céline, et al.
(författare)
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Are ducks able to adapt their migratory habits to environmental change?
- 2010
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Ingår i: The abstract book. ; , s. 25-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In order to predict waterfowl population changes due to variation in climate conditions, and habitat availability it is necessary to precisely understand the mechanisms driving their annual cycle. This is particularly challenging in migratory birds as they encounter a huge variety of habitats along their migratory routes, and different factors might affect their demographic parameters at different stages of their life-cycle. In this perspective spring migration stands out as a crucial period. During spring migration birds need both to complete their migration and to prepare for subsequent reproduction. An understanding of long-term factors influencing the timing of breeding in migratory birds is particularly important in order to predict how they might respond to future environmental changes. Anatidae are particularly interesting to study as they offer a wide variety of migratory strategies. We discuss some of the factors that are likely to affect individual choices and thus play a role in the evolution of migration. Based on long-term data sets, collected over 30 years, in the Archipelago Sea, SW Finland, we also offer a first insight into the changes in their spring arrival and breeding success of ducks in relation to environmental conditions.
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| 2. |
- Arzel, Céline, et al.
(författare)
-
Are ducks able to adapt their migratory habits to environmental change?
- 2010
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In order to predict waterfowl population changes due to variation in climate conditions, and habitat availability it is necessary to precisely understand the mechanisms driving their annual cycle. This is particularly challenging in migratory birds as they encounter a huge variety of habitats along their migratory routes, and different factors might affect their demographic parameters at different stages of their life-cycle. In this perspective spring migration stands out as a crucial period. During spring migration birds need both to complete their migration and to prepare for subsequent reproduction. An understanding of long-term factors influencing the timing of breeding in migratory birds is particularly important in order to predict how they might respond to future environmental changes. Anatidae are particularly interesting to study as they offer a wide variety of migratory strategies. We discuss some of the factors that are likely to affect individual choices and thus play a role in the evolution of migration. Based on long-term data sets, collected over 30 years, in the Archipelago Sea, SW Finland, we also offer a first insight into the changes in their spring arrival and breeding success of ducks in relation to environmental conditions.
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| 3. |
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| 4. |
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| 5. |
- Champagnon, Jocelyn, et al.
(författare)
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Changes in Mallard Anas platyrhynchos bill morphology after 30 years of supplemental stocking
- 2010
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Ingår i: Bird Study. - 0006-3657 .- 1944-6705. ; 57:3, s. 344-351
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Tidskriftsartikel (refereegranskat)abstract
- Capsule Massive releases of captive-reared Mallard for hunting purposes have been practiced for 30 years. During this period the number of lamellae per centimetre of bill length in wild Mallard populations has decreased. Aims Every year since the 1970s, several million captive Mallard have been released in Europe. This may lead to a spread of unnatural phenotypes into the wild. Nevertheless, the consequences of such introductions have not been examined. Methods Two widespread and common migratory ducks were studied: Mallard Anas platyrhynchos and Teal A. crecca. Mallard is the only duck species for which stocking programmes occur, and Teal served as a control. In a 'before-after' design, we compared duck bill lamellar density over the last 30 years. Results Lamellar density in Mallard, but not Teal, decreased. The observed 10% decrease occurred in the first (proximate) centimetre of the bill, the most crucial in terms of food filtration. Conclusions We hypothesize that the change in bill morphology was because of the propagation of captive Mallard into the wild: captive Mallard eat mainly large items, relaxing the natural selection pressure maintaining high lamellar density for sieving small prey in wild ducks.
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| 6. |
- Champagnon, Jocelyn, et al.
(författare)
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Changes in Mallard Anas platyrhynchos bill morphology after 30 years of supplemental stocking
- 2010
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Ingår i: Bird Study. - : Taylor and Francis Ltd.. - 0006-3657 .- 1944-6705. ; 57:3, s. 344-351
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Tidskriftsartikel (refereegranskat)abstract
- Capsule Massive releases of captive-reared Mallard for hunting purposes have been practiced for 30 years. During this period the number of lamellae per centimetre of bill length in wild Mallard populations has decreased. Aims Every year since the 1970s, several million captive Mallard have been released in Europe. This may lead to a spread of unnatural phenotypes into the wild. Nevertheless, the consequences of such introductions have not been examined. Methods Two widespread and common migratory ducks were studied: Mallard Anas platyrhynchos and Teal A. crecca. Mallard is the only duck species for which stocking programmes occur, and Teal served as a control. In a 'before-after' design, we compared duck bill lamellar density over the last 30 years. Results Lamellar density in Mallard, but not Teal, decreased. The observed 10% decrease occurred in the first (proximate) centimetre of the bill, the most crucial in terms of food filtration. Conclusions We hypothesize that the change in bill morphology was because of the propagation of captive Mallard into the wild: captive Mallard eat mainly large items, relaxing the natural selection pressure maintaining high lamellar density for sieving small prey in wild ducks.
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| 7. |
- Champagnon, Jocelyn, et al.
(författare)
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Conspecifics can be aliens too : a review of effects of restocking practices in vertebrates
- 2012
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Ingår i: Journal for Nature Conservation. - 1617-1381 .- 1618-1093. ; 20:4, s. 231-241
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Tidskriftsartikel (refereegranskat)abstract
- We review the indexed scientific literature (233 papers) dealing with ‘restocking’ of vertebrates, i.e. reinforcement of wild populations by release of individuals of the same species. We found evidence that restocking may have desired beneficial effects such as: increased genetic diversity and mitigation of Allee effects in small populations; increased size or even salvation of threatened populations; increased harvest opportunities; and, redirection of harvest pressure from wild to captive-bred individuals. However, restocking may also have negative effects like changes in behaviour, morphology, and demography in recipient populations, as well as enhancement of pathogen spread. Negative genetic effects on recipient populations include homogenisation, introduction of non-native genes, and loss of local adaptation. Research thus far is strongly biased towards birds and mammals, and geographically to Europe and North America. Restocking for conservation purposes has been studied more than that for harvest management, while the latter may be of far greater importance in terms of number of released individuals. Demographic and genetic effects have been studied more than effects on behaviour, which in turn have received more attention than effects on morphology and pathogen spread. There is a general tendency for research on restocking to be fragmented taxonomically and by biological sub-disciplines. Our review demonstrates that restocking practices may and do cause significant disruptions of natural patterns in wild recipient populations. It also highlights the diversity, frequency and extent of these activities, leading us to argue that restocking is an emerging conservation and ecosystem resilience issue of global significance. Based on this review we outline monitoring and research needs for the future. We also provide guidelines to practitioners in conservation, game management, fisheries, epidemiology and other fields involved in restocking of vertebrates, who are likely to benefit from merging their perspectives and adopting a more cross-taxonomical and interdisciplinary attitude when laying out future agendas for evaluation and policy-making in this field.
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| 8. |
- Champagnon, Jocelyn, et al.
(författare)
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Conspecifics can be aliens too : a review of effects of restocking practices in vertebrates
- 2012
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Ingår i: Journal for Nature Conservation. - : Urban und Fischer Verlag GmbH und Co. KG. - 1617-1381. ; 20:4, s. 231-241
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Tidskriftsartikel (refereegranskat)abstract
- We review the indexed scientific literature (233 papers) dealing with ‘restocking’ of vertebrates, i.e. reinforcement of wild populations by release of individuals of the same species. We found evidence that restocking may have desired beneficial effects such as: increased genetic diversity and mitigation of Allee effects in small populations; increased size or even salvation of threatened populations; increased harvest opportunities; and, redirection of harvest pressure from wild to captive-bred individuals. However, restocking may also have negative effects like changes in behaviour, morphology, and demography in recipient populations, as well as enhancement of pathogen spread. Negative genetic effects on recipient populations include homogenisation, introduction of non-native genes, and loss of local adaptation. Research thus far is strongly biased towards birds and mammals, and geographically to Europe and North America. Restocking for conservation purposes has been studied more than that for harvest management, while the latter may be of far greater importance in terms of number of released individuals. Demographic and genetic effects have been studied more than effects on behaviour, which in turn have received more attention than effects on morphology and pathogen spread. There is a general tendency for research on restocking to be fragmented taxonomically and by biological sub-disciplines. Our review demonstrates that restocking practices may and do cause significant disruptions of natural patterns in wild recipient populations. It also highlights the diversity, frequency and extent of these activities, leading us to argue that restocking is an emerging conservation and ecosystem resilience issue of global significance. Based on this review we outline monitoring and research needs for the future. We also provide guidelines to practitioners in conservation, game management, fisheries, epidemiology and other fields involved in restocking of vertebrates, who are likely to benefit from merging their perspectives and adopting a more cross-taxonomical and interdisciplinary attitude when laying out future agendas for evaluation and policy-making in this field.
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| 9. |
- Champagnon, Jocelyn, et al.
(författare)
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Do stocking programs result in maladapted populations? : mallard bill morphology after 30 years of massive releases
- 2011
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Ingår i: Abstracts. ; , s. 31-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Every year since the 1970s, several million captive Mallard have been released in Europe for hunting purposes. This may lead to a spread of unnatural phenotypes into the wild. Two widespread and common migratory ducks were studied: Mallard Anas platyrhynchos and Teal A. crecca. Mallard is the only duck species for which large-scale stocking programs occur in the region, and Teal hence serves as a control. In a « before-after » design, we compared duck bill lamellar density over the last thirty years. Lamellar density in Mallard, but not Teal, decreased. The observed 10 % decrease occurred in the first (proximate) centimetre of the bill, the most crucial in terms of food filtration. We hypothesize the observed change in bill morphology was due to the propagation of captive Mallard into the wild: captive Mallard mainly eat large items, relaxing the natural selection pressure maintaining high lamellar density for sieving small preys in wild ducks.
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| 10. |
- Champagnon, Jocelyn, et al.
(författare)
-
Do stocking programs result in maladapted populations? : mallard bill morphology after 30 years of massive releases
- 2011
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Every year since the 1970s, several million captive Mallard have been released in Europe for hunting purposes. This may lead to a spread of unnatural phenotypes into the wild. Two widespread and common migratory ducks were studied: Mallard Anas platyrhynchos and Teal A. crecca. Mallard is the only duck species for which large-scale stocking programs occur in the region, and Teal hence serves as a control. In a « before-after » design, we compared duck bill lamellar density over the last thirty years. Lamellar density in Mallard, but not Teal, decreased. The observed 10 % decrease occurred in the first (proximate) centimetre of the bill, the most crucial in terms of food filtration. We hypothesize the observed change in bill morphology was due to the propagation of captive Mallard into the wild: captive Mallard mainly eat large items, relaxing the natural selection pressure maintaining high lamellar density for sieving small preys in wild ducks.
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