| 1. |
- Dessborn, Lisa, et al.
(författare)
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Geese as vectors of nitrogen and phosphorus to freshwater systems
- 2016
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Ingår i: INLAND WATERS. - 2044-2041 .- 2044-205X. ; 6:1, s. 111-122
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Tidskriftsartikel (refereegranskat)abstract
- Many goose populations have increased dramatically over the past decades, which may influence inland waters used as roost sites. We reviewed the role of geese in the influx of nitrogen and phosphorus to freshwater systems. Several methods have been used to estimate guanotrophication impacts of geese. Water and sediment analysis have been conducted in areas of high and low geese presence; however, productive wetlands tend to attract more birds, and the causality is therefore ambiguous. Faecal addition experiments have attempted to estimate the impacts of droppings on water chemistry, sediments, algal growth, or invertebrate densities. The most common method of estimating goose guanotrophication is by extrapolation, usually based on multiplication of faecal production and its nutrient content. Based on such studies and those including information about daily migration patterns, we developed an approach to improve estimates of the nutrient contribution of geese. The relative role of geese in wetland eutrophication is also affected by the influx from alternative sources. The greatest guanotrophication impacts are likely found in areas with few alternative nutrient sources and with large goose flocks. Limited inflow and outflow of a freshwater system or a scarcity of wetland roosts may also increase problems at a local scale. Although several studies have looked at the impacts of geese on, for example, water chemistry or soil sediments, the effects are often smaller than expected, in part because no study to date has assessed the ecosystem response by including impacts on all levels, including water nutrient levels, nutrient sedimentation, chlorophyll content, and zooplankton response.
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| 2. |
- Elmberg, Johan, 1960-
(författare)
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Goose poop in the park
- 2018
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Ingår i: Bottom Line Health. - 1092-0129. ; 32:6
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Tidskriftsartikel (refereegranskat)
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| 3. |
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| 4. |
- Elmberg, Johan, 1960-, et al.
(författare)
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Passage patterns of seabirds in October at Cabo Carvoeiro Portugal, with special reference to the Balearic Shearwater Puffinus mauretanicus
- 2016
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Ingår i: Marine Ornithology. - 1018-3337 .- 2074-1235. ; 44:2, s. 151-156
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Tidskriftsartikel (refereegranskat)abstract
- Land-based counts of migrating seabirds remain essential to increase knowledge about their numbers and movements. To assess the value of Cabo Carvoeiro (Peniche, Portugal) as a monitoring site in the East Atlantic, we studied seabird species composition, passage patterns and flock size during mid-October 2014. During standardized counts, we observed nearly 8 000 seabirds of 17 species. The ratio of individuals passing in a southerly to southwesterly direction was >96% in all species, showing that genuine migrants were counted. The passage rate (birds/hour) was higher for Northern Gannets Morus bassanus than for any other species, by a factor of approximately 50 (morning mean 906/h, afternoon mean 1 153/h). The globally endangered Balearic Shearwaters Puffinus mauretanicus, Great Skuas Stercorarius skua and Pomarine Skuas S. pomarinus had passage rates of 10–25/h. Flock size distribution in the 11 most numerous species showed that most migrated singly or in groups of two. Flock size was larger in Balearic Shearwaters than in both Cory’s Calonectris borealis and Manx Shearwaters P. puffinus. Among skuas, flock size was larger in Pomarine than in Great Skuas. The passage rate of Manx Shearwaters was positively correlated with that of Northern Gannets, Great Skuas and Sandwich Terns Sterna sandvicensis. Northern Gannets showed a positive co-variation with Pomarine Skuas. Balearic and Sooty Shearwaters Ardenna griseus were the only species that did not show any significant co-variation with another species. Morning and afternoon passage rates did not differ significantly in any of the six most numerous species (Northern Gannets, Cory’s and Balearic Shearwaters, Great and Pomarine Skuas, and Sandwich Terns), or in Sooty Shearwaters (less numerous). Thus, the passage rates at Cabo Carvoeiro in October of Balearic Shearwaters and five other species were as high or higher than those reported from any other seawatch in Portugal, indicating the international value of seabird monitoring at Cabo Carvoeiro during the autumn migration.
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| 5. |
- Elmberg, Johan, 1960-, et al.
(författare)
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Population change in breeding boreal waterbirds in a 25‐year perspective : what characterises winners and losers?
- 2019
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Ingår i: Freshwater Biology. - : Wiley: 12 months. - 0046-5070 .- 1365-2427. ; 65:2, s. 167-177
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Tidskriftsartikel (refereegranskat)abstract
- Understanding drivers of variation and trends in biodiversity change is a general scientific challenge, but also crucial for conservation and management. Previous research shows that patterns of increase and decrease are not always consistent at different spatial scales, calling for approaches combining the latter. We here explore the idea that functional traits of species may help explaining divergent population trends.Complementing a previous community level study, we here analyse data about breeding waterbirds on 58 wetlands in boreal Fennoscandia, covering gradients in latitude as well as trophic status. We used linear mixed models to address how change in local abundance over 25 years in 25 waterbird species are associated with life history traits, diet, distribution, breeding phenology, and habitat affinity.Mean abundance increased in 10 species from 1990/1991 to 2016, whereas it decreased in 15 species. Local population increases were associated with species that are early breeders and have small clutches, an affinity for luxurious wetlands, an herbivorous diet, and a wide breeding range rather than a southern distribution. Local decreases, by contrast, were associated with species having large clutches and invertivorous diet, as well as being late breeders and less confined to luxurious wetlands. The three species occurring on the highest number of wetlands all decreased in mean abundance.The fact that early breeders have done better than late fits well with previous research about adaptability to climate change, that is, response to earlier springs. We found only limited support for the idea that life history traits are good predictors of wetland level population change. Instead, diet turned out to be a strong candidate for an important driver of population change, as supported by a general decrease of invertivores and a concomitant increase of large herbivores.In a wider perspective, future research needs to address whether population growth of large‐bodied aquatic herbivores affects abundance of co‐occurring invertivorous species, and if so, if this is due to habitat alteration, or to interference or exploitative competition.
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| 6. |
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| 7. |
- Elmberg, Johan, 1960-, et al.
(författare)
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Utsatta änder inte som vilda
- 2018
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Ingår i: Svensk Jakt. ; :10, s. 51-51
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 8. |
- Holopainen, Sari, et al.
(författare)
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Sustainable management of migratory European ducks : finding model species
- 2018
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Ingår i: Wildlife Biology. - : Nordic Council for Wildlife Research (NKV). - 0909-6396 .- 1903-220X.
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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.
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| 9. |
- Holopainen, Sari, et al.
(författare)
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Sustainable management of migratory European ducks : finding model species
- 2018
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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.
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| 10. |
- Olsson, Camilla, 1991-, et al.
(författare)
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Long-distance and local movements of greylag geese in present-day agricultural landscapes
- 2018
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Ingår i: 18th Conference of Goose Specialist Group. - : Marine Institute of Klaipeda University. - 9789955189794 ; , s. 77-
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Konferensbidrag (refereegranskat)abstract
- Recent changes in environmental conditions together with increasing goose populations have completely changed the ballgame for geese in Europe. To better understand their current distribution and foraging patterns, this project will explore how geese utilize the agricultural landscape, with focus on their movements, field selection and foraging patterns. We fitted 199 Greylag geese with neck-collars and 64 with GPS transmitters at 5 locations in Sweden. The tagged geese will be used for studying movement patterns at a field-tofield level. However, the GPS transmitters also deliver data that can be used together with re-sightnings of neck-collared geese to unravel large-scale movement patterns of the Swedish Greylag goose population. Preliminary results from GPS positions received June--November 2017 indicate a varation in migration patterns and wintering grounds, depending on the origin of the geese. Geese breeding and molting in the southern parts of Sweden seem to migrate shorter distances, and have spent most of their time during the autumn months in Denmark, or in the southernmost parts of Sweden, while the geese marked farther north migrated earlier and moved longer distances, with the majority spending the autumn in Germany and the Netherlands.
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