| 1. |
- Fox, Anthony D., et al.
(författare)
-
Recent changes in the abundance of Common Pochard Aythya ferina breeding in Europe
- 2016
-
Ingår i: Wildfowl. - 0954-6324. ; 66, s. 22-40
-
Forskningsöversikt (refereegranskat)abstract
- National accounts suggest that the Common Pochard Aythya ferina was an uncommon breeding bird throughout western Europe before 1850. Extensions to the breeding range in the late 19th century were potentially aided by the rapid development of managed fish-ponds in eastern Europe, which provided suitable novel habitat at that time. Expansion into western Europe followed in subsequent decades. Wetland and waterbody eutrophication throughout Europe, which likely provided food and cover for the birds, may have accelerated the rapid expansion from the 1950s until the early 1980s. Widespread declines in the last 30 years, especially in eastern Europe, where breeding numbers are highest, are possibly linked to intensification and/or abandonment of freshwater fish farming and changes in water quality. Studies show that Pochard gain fitness benefits from nesting in Black-headed Gull Chroicocephalus ridibundus colonies and hence has been affected by major losses of European gull colonies in the last 30 years. The spread of alien fish species such as the Carp Cyprinus carpio, which compete with Pochard for food resources, is a problem in the Mediterranean region. Changing predation pressures (in some cases linked to invasive alien mammals) are also implicated in some areas. Relatively modest numbers breeding in the UK, France and the Netherlands have remained stable or increased over the same recent span of years, confirming that different factors currently affect Pochard breeding abundance throughout its range. We urgently need better information relating to key factors affecting Pochard breeding success and abundance, which is currently showing an unfavourable conservation status throughout much of Europe.
|
|
| 2. |
- Brochet, Anne-Laure, et al.
(författare)
-
Is diet segregation between dabbling ducks due to food partitioning? : a review of seasonal patterns in the Western Palearctic
- 2012
-
Ingår i: Journal of Zoology. - 0952-8369 .- 1469-7998. ; 286:3, s. 171-178
-
Tidskriftsartikel (refereegranskat)abstract
- Within the paradigm of resource-limited competition-structured communities, dabbling ducks (Anas spp.) have been used as a textbook example of how morphological differences, notably bill lamellar density and body length, may allow sympatric species to partition food and hence coexist. We reviewed all accessible diet studies from the Western Palearctic for three closely related dabbling duck species, mallard (Anas platyrhynchos), pintail (A.?acuta) and teal (A.?crecca), and present a comprehensive list of the food items (invertebrates, seeds, vegetative parts of plants) ingested. To assess the circumannual perspective of niche separation, we evaluated size distribution of ingested seeds among seasons and duck species. There was a significant difference among duck species in mean size and mass of ingested seeds, as well as in diet composition, with the largest seeds consumed by the largest species (mallard) with the coarsest bill filter apparatus (lamellae), and the smallest seeds by the smallest species (teal) with the finest bill lamellae. However, no effect of season was found, suggesting consistent diet segregation among species throughout the annual cycle of ducks and over large geographical areas. We argue that the patterns of food size separation between the three species are compatible with the idea of coexistence under interspecific competition.
|
|
| 3. |
- Brochet, Anne-Laure, et al.
(författare)
-
Is diet segregation between dabbling ducks due to food partitioning? : a review of seasonal patterns in the Western Palearctic
- 2012
-
Ingår i: Journal of Zoology. - : Wiley-Blackwell. - 0952-8369 .- 1469-7998. ; 286:3, s. 171-178
-
Tidskriftsartikel (refereegranskat)abstract
- Within the paradigm of resource-limited competition-structured communities, dabbling ducks (Anas spp.) have been used as a textbook example of how morphological differences, notably bill lamellar density and body length, may allow sympatric species to partition food and hence coexist. We reviewed all accessible diet studies from the Western Palearctic for three closely related dabbling duck species, mallard (Anas platyrhynchos), pintail (A.?acuta) and teal (A.?crecca), and present a comprehensive list of the food items (invertebrates, seeds, vegetative parts of plants) ingested. To assess the circumannual perspective of niche separation, we evaluated size distribution of ingested seeds among seasons and duck species. There was a significant difference among duck species in mean size and mass of ingested seeds, as well as in diet composition, with the largest seeds consumed by the largest species (mallard) with the coarsest bill filter apparatus (lamellae), and the smallest seeds by the smallest species (teal)with the finest bill lamellae. However, no effect of season was found, suggesting consistent diet segregation among species throughout the annual cycle of ducks and over large geographical areas. We argue that the patterns of food size separation between the three species are compatible with the idea of coexistence under interspecific competition.
|
|
| 4. |
- Champagnon, Jocelyn, et al.
(författare)
-
Assessing the genetic impact of massive restocking on wild mallard
- 2013
-
Ingår i: Animal Conservation. - : Wiley: 12 months. - 1367-9430 .- 1469-1795. ; 16:3, s. 295-305
-
Tidskriftsartikel (refereegranskat)abstract
- Captive-bred mallards Anas platyrhynchos have been released for hunting purposes at a very large scale in Europe since the mid-1970s. In spite of a potential genetic impact, the actual contribution of restocked mallards to the genome of the target population has received little attention. The genetic structure of modern wild mallards in the Camargue, Southern France, was assessed from two samples: one originating from shot birds in hunting bags and one from presumed wild ducks captured alive in a hunting-free reserve. Reference samples originated from five mallard farms, as well as from museum samples collected before the mid-1970s (i.e. before massive mallard releases started). Our results revealed that the genetic signature of wild wintering mallards has not changed significantly because museum and presumed wild samples from the Camargue hunting-free nature reserve were genetically similar, and clearly differentiated from the farm mallards. This suggests that mallard releases in the Camargue or elsewhere in France, although massive, have not actually translated into complete admixture of wild and captive genomes, most likely due to low survival of released birds once in the wild. Nevertheless, although genetic introgression of the wild population by captive-bred was contained, we found significant rates of hybridization between wild and captive-bred mallards in modern samples. This result suggests that long-term releases of captive-bred mallards, if carried on at such large scale, could compromise irreversibly the genetic structure and composition of European mallards. This work contributes to fill in the gap on the monitoring of the genetic consequences of large-scale game releases for exploitation.
|
|
| 5. |
- Champagnon, Jocelyn, et al.
(författare)
-
Assessing the genetic impact of massive restocking on wild mallard
- 2013
-
Ingår i: Animal Conservation. - : Wiley-Blackwell. - 1367-9430 .- 1469-1795. ; 16:3, s. 295-305
-
Tidskriftsartikel (refereegranskat)abstract
- Captive-bred mallards Anas platyrhynchos have been released for hunting purposes at a very large scale in Europe since the mid-1970s. In spite of a potential genetic impact, the actual contribution of restocked mallards to the genome of the target population has received little attention. The genetic structure of modern wild mallards in the Camargue, Southern France, was assessed from two samples: one originating from shot birds in hunting bags and one from presumed wild ducks captured alive in a hunting-free reserve. Reference samples originated from five mallard farms, as well as from museum samples collected before the mid-1970s (i.e. before massive mallard releases started). Our results revealed that the genetic signature of wild wintering mallards has not changed significantly because museum and presumed wild samples from the Camargue hunting-free nature reserve were genetically similar, and clearly differentiated from the farm mallards. This suggests that mallard releases in the Camargue or elsewhere inFrance, although massive, have not actually translated into complete admixture of wild and captive genomes, most likely due to low survival of released birds once in the wild. Nevertheless, although genetic introgression of the wild population by captive-bred was contained, we found significant rates of hybridization between wild and captive-bred mallards in modern samples. This result suggests that long-term releases of captive-bred mallards, if carried on at such large scale, could compromise irreversibly the genetic structure and composition of European mallards. This work contributes to fill in the gap on the monitoring of the genetic consequences of large-scale game releases for exploitation.
|
|
| 6. |
- Dessborn, Lisa, et al.
(författare)
-
Geographical and temporal patterns in the diet of pintail Anas acuta, wigeon Anas penelope, mallard Anas platyrhynchos and teal Anas crecca in the Western Palearctic
- 2011
-
Ingår i: European Journal of Wildlife Research. - : Springer Verlag. - 1612-4642 .- 1439-0574. ; 57:6, s. 1119-1129
-
Tidskriftsartikel (refereegranskat)abstract
- Dabbling ducks are important quarry species, and as a result, they are relatively well studied. Over the last century, considerable effort has been made to describe their diet and food requirements. In this review, we compile present knowledge about the diet of four widespread dabbling ducks (wigeon, pintail, mallard and teal) in the Western Palearctic. Previous diet research has a spatio-temporal bias towards autumn/winter and the western parts of Europe. The limited number of studies from the breeding season reveals an increase in invertebrates in the diet compared to other seasons, but with some differences between adults and ducklings. Adult ducks eat a larger proportion of benthic invertebrates, whereas ducklings feed relatively more on emerging invertebrates. The most important plant species (seeds) based on frequency occurrence was found to vary with a geographic gradient. Carex spp., Hordeum vulgare and Hippuris vulgaris are common in the diet of birds at northern latitudes, whereas taxa such as Oryzasativa, Potamogeton pectinatus and Scirpus spp. are common in the south. The reviewed studies are based on the contents of different parts of the digestive system and on a variety of methods to quantify food items. The variations in sampling techniques and shortage of articles from the breeding season and some geographic regions highlight the need for future studies. In the future, it is important to standardize sampling techniques to improve the possibility to compare studies and to obtain a more representative view of the diet of dabbling ducks in Europe.
|
|
| 7. |
- Söderquist, Pär, et al.
(författare)
-
Admixture between released and wild game birds: a changing genetic landscape in European mallards (Anas platyrhynchos)
- 2017
-
Ingår i: European Biophysics Journal. - : Springer Verlag (Germany). - 0175-7571 .- 1432-1017. ; 63
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 8. |
- Söderquist, Pär, et al.
(författare)
-
Admixture between released and wild game birds: a changing genetic landscape in European mallards (Anas platyrhynchos)
- 2017
-
Ingår i: European Biophysics Journal. - : Springer Verlag. - 0175-7571 .- 1432-1017. ; 63:6
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 9. |
- Arzel, C., et al.
(författare)
-
A flyway perspective of foraging activity in Eurasian Green-winged Teal, Anas crecca crecca
- 2007
-
Ingår i: Canadian Journal of Zoology. - 0008-4301 .- 1480-3283. ; 85:1, s. 81-91
-
Tidskriftsartikel (refereegranskat)abstract
- Time-activity budgets in the family Anatidae are available for the wintering and breeding periods. We present the first flyway-level study of foraging time in a long-distance migrant, the Eurasian Green-winged Teal, Anas crecca crecca L., 1758 ("Teal"). Behavioral data from early and late spring staging, breeding, and molting sites were collected with standardized protocols to explore differences between the,sexes, seasons, and diel patterns. Teal foraging activity was compared with that of the Mallard, Anas platyrhynchos L., 1758 and Northern Shoveler, Anas clypeata L., 1758, and the potential effects of duck density and predator-caused disturbance were explored. In early spring, foraging time was moderate (50.5%) and mostly nocturnal (45%). It increased dramatically in all three species at migration stopovers and during molt, mostly because of increased diurnal foraging, while nocturnal foraging remained fairly constant along the flyway. These patterns adhere to the "income breeding" strategy expected for this species. No differences between the sexes were recorded in either species studied. Teal foraging time was positively correlated with density of Teal and all ducks present, but negatively correlated with predator disturbance. Our study suggests that Teal, in addition to being income breeders, may also be considered as income migrants; they find the energy necessary to migrate at staging sites along the flyway.
|
|
| 10. |
- Arzel, C., et al.
(författare)
-
A flyway perspective of foraging activity in Eurasian Green-winged Teal, Anas crecca crecca
- 2007
-
Ingår i: Canadian Journal of Zoology. - : National Research Council of Canada. - 0008-4301 .- 1480-3283. ; 85:1, s. 81-91
-
Tidskriftsartikel (refereegranskat)abstract
- Time-activity budgets in the family Anatidae are available for the wintering and breeding periods. We present the first flyway-level study of foraging time in a long-distance migrant, the Eurasian Green-winged Teal, Anas crecca crecca L., 1758 ("Teal"). Behavioral data from early and late spring staging, breeding, and molting sites were collected with standardized protocols to explore differences between the,sexes, seasons, and diel patterns. Teal foraging activity was compared with that of the Mallard, Anas platyrhynchos L., 1758 and Northern Shoveler, Anas clypeata L., 1758, and the potential effects of duck density and predator-caused disturbance were explored. In early spring, foraging time was moderate (50.5%) and mostly nocturnal (45%). It increased dramatically in all three species at migration stopovers and during molt, mostly because of increased diurnal foraging, while nocturnal foraging remained fairly constant along the flyway. These patterns adhere to the "income breeding" strategy expected for this species. No differences between the sexes were recorded in either species studied. Teal foraging time was positively correlated with density of Teal and all ducks present, but negatively correlated with predator disturbance. Our study suggests that Teal, in addition to being income breeders, may also be considered as income migrants; they find the energy necessary to migrate at staging sites along the flyway.
|
|
| 11. |
- Arzel, Céline, et al.
(författare)
-
Ecology of spring-migrating Anatidae : a review
- 2006
-
Ingår i: Journal of Ornithology = Journal fur Ornithologie. - 0021-8375 .- 1439-0361. - 0021-8375 ; 147:2, s. 167-184
-
Forskningsöversikt (refereegranskat)abstract
- Spring migration is generally considered as a crucial period of the year for many birds, not the least due to its supposed importance for subsequent breeding success. By reviewing the existing literature for Anatidae (ducks, geese, and swans), we show that little is known about their ecology in spring, although some goose species are exceptions. Another general pattern is that the ecology of Anatidae at staging sites is particularly neglected. Existing studies tend to focus on questions dealing with acquisition of nutrient reserves, whereas almost nothing has been published about stopover habitats, time use, microhabitat use, foraging behaviour, food availability, food limitation, diet selection, and interspecific relationships. Besides summarising present knowledge, we identify taxonomic groups and topics for which gaps of knowledge appear the most evident, thereby also highlighting research needs for the future.
|
|
| 12. |
- Arzel, Céline, et al.
(författare)
-
Ecology of spring-migrating Anatidae : a review
- 2006
-
Ingår i: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375. ; 147:2, s. 167-184
-
Forskningsöversikt (refereegranskat)abstract
- Spring migration is generally considered as a crucial period of the year for many birds, not the least due to its supposed importance for subsequent breeding success. By reviewing the existing literature for Anatidae (ducks, geese, and swans), we show that little is known about their ecology in spring, although some goose species are exceptions. Another general pattern is that the ecology of Anatidae at staging sites is particularly neglected. Existing studies tend to focus on questions dealing with acquisition of nutrient reserves, whereas almost nothing has been published about stopover habitats, time use, microhabitat use, foraging behaviour, food availability, food limitation, diet selection, and interspecific relationships. Besides summarising present knowledge, we identify taxonomic groups and topics for which gaps of knowledge appear the most evident, thereby also highlighting research needs for the future.
|
|
| 13. |
- Arzel, Celiné, et al.
(författare)
-
Experimental functional response and inter-individual variation in foraging rate of teal (Anas crecca)
- 2007
-
Ingår i: Behavioural Processes. - 0376-6357 .- 1872-8308. - 0376-6357 ; 75:1, s. 66-71
-
Tidskriftsartikel (refereegranskat)abstract
- The functional response, i.e. the change in per capita food intake rate per time unit with changed food availability, is a widely used too] for understanding the ecology and behaviour of animals. However, waterfowl remain poorly explored in this context. In an aviary experiment we derived a functional response curve for teal (Anas crecca) foraging on rice (Oryza sativa) seeds. We found a linear relationship between intake rate and seed density, as expected for a filter-feeder. At high seed densities we found a threshold, above which intake rate still increased linearly but with a lower slope, possibly reflecting a switch from filter-feeding to a scooping foraging mode. The present study shows that food intake rate in teal is linearly related to food availability within the range of naturally occurring seed densities, a finding with major implications for management and conservation of wetland habitats.
|
|
| 14. |
- Arzel, Celiné, et al.
(författare)
-
Experimental functional response and inter-individual variation in foraging rate of teal (Anas crecca)
- 2007
-
Ingår i: Behavioural Processes. - : Elsevier. - 0376-6357 .- 1872-8308. ; 75:1, s. 66-71
-
Tidskriftsartikel (refereegranskat)abstract
- The functional response, i.e. the change in per capita food intake rate per time unit with changed food availability, is a widely used too] for understanding the ecology and behaviour of animals. However, waterfowl remain poorly explored in this context. In an aviary experiment we derived a functional response curve for teal (Anas crecca) foraging on rice (Oryza sativa) seeds. We found a linear relationship between intake rate and seed density, as expected for a filter-feeder. At high seed densities we found a threshold, above which intake rate still increased linearly but with a lower slope, possibly reflecting a switch from filter-feeding to a scooping foraging mode. The present study shows that food intake rate in teal is linearly related to food availability within the range of naturally occurring seed densities, a finding with major implications for management and conservation of wetland habitats.
|
|
| 15. |
- Elmberg, Johan, et al.
(författare)
-
Farmed European mallards are genetically different and cause introgression in the wild population following releases
- 2016
-
Konferensbidrag (refereegranskat)abstract
- 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.
|
|
| 16. |
- Elmberg, Johan, et al.
(författare)
-
Farmed European mallards are genetically different and cause introgression in the wild population following releases
- 2016
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 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.
|
|
| 17. |
- Guillemain, Matthieu, et al.
(författare)
-
Agent-based modeling may help to merge research traditions in foraging ecology in Europe and North America
- 2017
-
Ingår i: Wildlife Society bulletin. - 0091-7648 .- 1938-5463. ; 41:1, s. 170-176
-
Tidskriftsartikel (refereegranskat)abstract
- Although ducks have long been popular research subjects in both North America and Europe, geographical divergences in research orientation have developed during the past several decades for studying foraging ecology. In North America, foraging studies largely focused on the population level with an emphasis on foraging energetics aimed at improving waterfowl production through increased carrying capacity of wetlands in breeding areas, an approach later expanded to nonbreeding grounds. In Europe, studies have instead focused on inter-individual differences in behavior of foraging ducks, with an emphasis on individual efficiency (e.g., methods, intake rate, patch choice) within the framework of optimal foraging theory. We suggest that agent-based models (also termed individual-based behavior models), which aim to predict habitat use from the heterogeneous behavior of different individual agents, can help to unify these approaches and would benefit considerably from increased collaboration and integration of the approaches of both North American and European researchers.
|
|
| 18. |
- Guillemain, Matthieu, et al.
(författare)
-
Agent-based modeling may help to merge research traditions in foraging ecology in Europe and North America
- 2017
-
Ingår i: Wildlife Society Bulletin. - : Wiley-Blackwell. - 0091-7648 .- 1938-5463. ; 41:1, s. 170-176
-
Tidskriftsartikel (refereegranskat)abstract
- Although ducks have long been popular research subjects in both North America and Europe, geographical divergences in research orientation have developed during the past several decades for studying foraging ecology. In North America, foraging studies largely focused on the population level with an emphasis on foraging energetics aimed at improving waterfowl production through increased carrying capacity of wetlands in breeding areas, an approach later expanded to nonbreeding grounds. In Europe, studies have instead focused on inter-individual differences in behavior of foraging ducks, with an emphasis on individual efficiency (e.g., methods, intake rate, patch choice) within the framework of optimal foraging theory. We suggest that agent-based models (also termed individual-based behavior models), which aim to predict habitat use from the heterogeneous behavior of different individual agents, can help to unify these approaches and would benefit considerably from increased collaboration and integration of theapproaches of both North American and European researchers.
|
|
| 19. |
- Guillemain, M, et al.
(författare)
-
Mallard (Anas platyrhynchos Linnaeus, 1758)
- 2020
-
Ingår i: Invasive birds. - Wallingford : CABI International. - 9781789242065 ; , s. 194-199
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
- Holopainen, Sari, et al.
(författare)
-
Sustainable management of migratory European ducks : finding model species
- 2018
-
Ingår i: Wildlife Biology. - : Nordic Council for Wildlife Research (NKV). - 0909-6396 .- 1903-220X.
-
Tidskriftsartikel (refereegranskat)abstract
- Eurasian migratory duck species represent a natural resource shared between European countries. As is evident throughout human harvest history, lack of coordinated management and monitoring at appropriate levels often leads to ‘the tragedy of the commons’, where shared populations suffer overexploitation. Effective management can also be hampered by poor understanding of the factors that limit and regulate migratory populations throughout their flyways, and over time. Following decades of population increase, some European duck populations now show signs of levelling off or even decline, underlining the need for more active and effective management. In Europe, the existing mechanisms for delivering effective management of duck populations are limited, despite the need and enthusiasm for establishing adaptive management (AM) schemes for wildlife populations. Existing international legal agreements already oblige European countries to sustainably manage migratory waterbirds. Although the lack of coordinated demographic and hunting data remains a challenge to sustainable management planning, AM provides a robust decision-making framework even in the presence of uncertainty regarding demographic and other information. In this paper we investigate the research and monitoring needs in Europe to successfully apply AM to ducks, and search for possible model species, focusing on freshwater species (in contrast to sea duck species) in the East Atlantic flyway. Based on current knowledge, we suggest that common teal Anas crecca, Eurasian wigeon Mareca penelope and common goldeneye Bucephala clangula represent the best species for testing the application of an AM modelling approach to duck populations in Europe. Applying AM to huntable species with relatively good population data as models for broader implementation represents a cost effect to develop AM on a European flyway scale for ducks, and potentially other waterbirds in the future.
|
|
| 24. |
- Holopainen, Sari, et al.
(författare)
-
Sustainable management of migratory European ducks : finding model species
- 2018
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Eurasian migratory ducks are a natural resource shared between multiple European countries. Due to lack of flyway-level management and monitoring, there is a risk of “the tragedy of the commons” arising, where populations are overexploited. Effective management may also be hindered by a poor understanding of the factors that limit and regulate migratory populations throughout their flyways, and over time. Following decades of population increase, some European duck populations now show signs of levelling off or even decline, underlining the need for more active management. In Europe, we lack effective common tools to manage duck populations, despite the need and enthusiasm for establishing flyway-level adaptive management (AM) schemes for migratory birds. There are several international legal agreements (e.g. EEC Birds Directive, AEWA) that oblige European countries to sustainably manage migratory birds and their habitats. Although the lack of coordinated demographic and hunting data remains a challenge to sustainable management planning for waterfowl, AM provides a robust decision-making framework even in the presence of uncertainty.We investigate the research and monitoring needs in Europe to successfully apply AM to ducks, and search for possible model species, focusing on freshwater duck species. Our geographical focus is NW Europe (excluding Russia), the area utilized by ducks in the East-Atlantic flyway. Based on current knowledge and their wide distribution, we suggest that Common Teal Anas crecca, Eurasian Wigeon Mareca penelopeand Common Goldeneye Bucephala clangulawould be the best species for testing the application of an AM modelling approach for ducks in Europe. Applying AM to huntable species with relatively good population data as models for broader implementation represents a cost effective way of starting to develop AM on a European flyway scale for ducks and other harvested waterbirds.
|
|
| 25. |
- Holopainen, Sari, et al.
(författare)
-
Sustainable management of migratory European ducks : finding model species
- 2018
-
Ingår i: Wildlife Biology. - : Nordic Council for Wildlife Research. - 0909-6396 .- 1903-220X.
-
Tidskriftsartikel (refereegranskat)abstract
- Eurasian migratory duck species represent a natural resource shared between European countries. As is evident throughout human harvest history, lack of coordinated management and monitoring at appropriate levels often leads to ‘the tragedy of the commons’, where shared populations suffer overexploitation. Effective management can also be hampered by poor understanding of the factors that limit and regulate migratory populations throughout their flyways, and over time. Following decades of population increase, some European duck populations now show signs of levelling off or even decline, underlining the need for more active and effective management. In Europe, the existing mechanisms for delivering effective management of duck populations are limited, despite the need and enthusiasm for establishing adaptive management (AM) schemes for wildlife populations. Existing international legal agreements already oblige European countries to sustainably manage migratory waterbirds. Although the lack of coordinated demographic and hunting data remains a challenge to sustainable management planning, AM provides a robust decision-making framework even in the presence of uncertainty regarding demographic and other information. In this paper we investigate the research and monitoring needs in Europe to successfully apply AM to ducks, and search for possible model species, focusing on freshwater species (in contrast to sea duck species) in the East Atlantic flyway. Based on current knowledge, we suggest that common teal Anas crecca, Eurasian wigeon Mareca penelope and common goldeneye Bucephala clangula represent the best species for testing the application of an AM modelling approach to duck populations in Europe. Applying AM to huntable species with relatively good population data as models for broader implementation represents a cost effect to develop AM on a European flyway scale for ducks, and potentially other waterbirds in the future.
|
|
| 26. |
- Holopainen, Sari, et al.
(författare)
-
Sustainable management of migratory European ducks : finding model species
- 2018
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Eurasian migratory ducks are a natural resource shared between multiple European countries. Due to lack of flyway-level management and monitoring, there is a risk of “the tragedy of the commons” arising, where populations are overexploited. Effective management may also be hindered by a poor understanding of the factors that limit and regulate migratory populations throughout their flyways, and over time. Following decades of population increase, some European duck populations now show signs of levelling off or even decline, underlining the need for more active management. In Europe, we lack effective common tools to manage duck populations, despite the need and enthusiasm for establishing flyway-level adaptive management (AM) schemes for migratory birds. There are several international legal agreements (e.g. EEC Birds Directive, AEWA) that oblige European countries to sustainably manage migratory birds and their habitats. Although the lack of coordinated demographic and hunting data remains a challenge to sustainable management planning for waterfowl, AM provides a robust decision-making framework even in the presence of uncertainty. We investigate the research and monitoring needs in Europe to successfully apply AM to ducks, and search for possible model species, focusing on freshwater duck species. Our geographical focus is NW Europe (excluding Russia), the area utilized by ducks in the East-Atlantic flyway. Based on current knowledge and their wide distribution, we suggest that Common Teal Anas crecca, Eurasian Wigeon Mareca penelopeand Common Goldeneye Bucephala clangulawould be the best species for testing the application of an AM modelling approach for ducks in Europe. Applying AM to huntable species with relatively good population data as models for broader implementation represents a cost effective way of starting to develop AM on a European flyway scale for ducks and other harvested waterbirds.
|
|
| 27. |
- Kraus, R.H.S., et al.
(författare)
-
Freigelassenes Federwild führt zu kontinent-weiter genetischer Introgression : die sich ändernde genetische Landschaft der Stockente Anas platyrhynchos in Europa
- 2015
-
Konferensbidrag (refereegranskat)abstract
- 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.
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
|
|
