| 1. |
- Champagnon, Jocelyn, et al.
(author)
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Changes in Mallard Anas platyrhynchos bill morphology after 30 years of supplemental stocking
- 2010
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In: Bird Study. - 0006-3657 .- 1944-6705. ; 57:3, s. 344-351
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Journal article (peer-reviewed)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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| 2. |
- Champagnon, Jocelyn, et al.
(author)
-
Changes in Mallard Anas platyrhynchos bill morphology after 30 years of supplemental stocking
- 2010
-
In: Bird Study. - : Taylor and Francis Ltd.. - 0006-3657 .- 1944-6705. ; 57:3, s. 344-351
-
Journal article (peer-reviewed)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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| 3. |
- Champagnon, Jocelyn, et al.
(author)
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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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In: Abstracts. ; , s. 31-
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Conference paper (other academic/artistic)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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| 4. |
- Champagnon, Jocelyn, et al.
(author)
-
Do stocking programs result in maladapted populations? : mallard bill morphology after 30 years of massive releases
- 2011
-
Conference paper (other academic/artistic)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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| 5. |
- Elmberg, Johan, 1960-, et al.
(author)
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Putting density dependence in perspective : nest density, nesting phenology, and biome, all matter to survival of simulated mallard Anas platyrhynchos nests
- 2009
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In: Journal of Avian Biology. - 0908-8857 .- 1600-048X. - 0908-8857 ; 40:3, s. 317-326
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Journal article (peer-reviewed)abstract
- Breeding success in ground-nesting birds is primarily determined by nest survival, which may be density-dependent, but the generality of this pattern remains untested. In a replicated crossover experiment conducted on 30 wetlands, survival of simulated mallard nests was related to "biome" (n=14 mediterranean and 16 boreal wetlands), breeding "phenology" (early vs late nests), and "density" (2 vs 8 nests per 225 m shoreline). Local abundances of "waterfowl", "other waterbirds", and "avian predators" were used as covariates. We used an information-theoretic approach and Program MARK to select among competing models. Nest survival was lower in late nests compared with early ones, and it was lower in the mediterranean than in the boreal study region. High-density treatment nests suffered higher depredation rates than low-density nests during days 1-4 of each experimental period. Nest survival was negatively associated with local abundance of "waterfowl" in the boreal but not in the mediterranean biome. Effect estimates from the highest-ranked model showed that nest "density" (d 1-4) had the strongest impact on model fit; i.e. three times that of "biome" and 1.5 times that of "phenology". The latter's effect, in turn, was twice that of "biome". We argue that our study supports the idea that density-dependent nest predation may be temporally and spatially widespread in waterfowl. We also see an urgent need for research of how waterfowl nesting phenology is matched to that of prey and vegetation.
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| 6. |
- Elmberg, Johan, et al.
(author)
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Putting density dependence in perspective : nest density, nesting phenology, and biome, all matter to survival of simulated mallard Anas platyrhynchos nests
- 2009
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In: Journal of Avian Biology. - : Wiley-Blackwell Publishing Ltd. - 0908-8857 .- 1600-048X. ; 40:3, s. 317-326
-
Journal article (peer-reviewed)abstract
- Breeding success in ground-nesting birds is primarily determined by nest survival, which may be density-dependent, but the generality of this pattern remains untested. In a replicated crossover experiment conducted on 30 wetlands, survival of simulated mallard nests was related to "biome" (n=14 mediterranean and 16 boreal wetlands), breeding "phenology" (early vs late nests), and "density" (2 vs 8 nests per 225 m shoreline). Local abundances of "waterfowl", "other waterbirds", and "avian predators" were used as covariates. We used an information-theoretic approach and Program MARK to select among competing models. Nest survival was lower in late nests compared with early ones, and it was lower in the mediterranean than in the boreal study region. High-density treatment nests suffered higher depredation rates than low-density nests during days 1-4 of each experimental period. Nest survival was negatively associated with local abundance of "waterfowl" in the boreal but not in the mediterranean biome. Effect estimates from the highest-ranked model showed that nest "density" (d 1-4) had the strongest impact on model fit; i.e. three times that of "biome" and 1.5 times that of "phenology". The latter's effect, in turn, was twice that of "biome". We argue that our study supports the idea that density-dependent nest predation may be temporally and spatially widespread in waterfowl. We also see an urgent need for research of how waterfowl nesting phenology is matched to that of prey and vegetation.
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| 7. |
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| 8. |
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| 9. |
- Folkesson, Mattias, 1972-, et al.
(author)
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The expression of heat shock protein in human skeletal muscle : effects of muscle fibre phenotype and training background
- 2013
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In: Acta Physiologica. - : Wiley-Blackwell. - 1748-1708 .- 1748-1716. ; 209:1, s. 26-33
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Journal article (peer-reviewed)abstract
- Aim: Exercise-induced adaptations of skeletal muscle are related to training mode and can be muscle fibre type specific. This study aimed to investigate heat shock protein expression in type I and type II muscle fibres in resting skeletal muscle of subjects with different training backgrounds.Methods: Three groups of subjects were included: healthy active not engaged in any training programme (ACT, n = 12), resistance trained (RES, n = 6) and endurance trained (END, n = 8). Biopsies were obtained from vastus lateralis, and immunohistochemistry was performed using monoclonal antibodies against myosin heavy chain I and IIA, αB-crystallin, HSP27, HSP60 and HSP70.Results: In ACT and RES, but not in END, a fibre type–specific expression with higher staining intensity in type I than type II fibres was seen for αB-crystallin. The opposite (II > I) was found for HSP27 in subjects from ACT (6 of 12 subjects) and RES (3 of 6), whereas all subjects from END displayed uniform staining. HSP60 showed no fibre-specific expression. HSP70 displayed a fibre-specific expression pattern (I > II) in ACT (4 of 12), but not in END or RES.Conclusion: This study shows that the level of expression of the different HSPs in human skeletal muscle is influenced by muscle fibre phenotype. The fibre type–specific expression of HSP70 is influenced by resistance and endurance training, whereas those of αB-crystallin and HSP27 is influenced only by endurance training, suggesting the existence of a training-modality-specific action on the adaptive processes including heat shock proteins in human skeletal muscle.
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