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- Liljebäck, Niklas, et al.
(författare)
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Learning from long time series of harvest and population data : Swedish lessons for European goose management
- 2021
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Ingår i: Wildlife Biology. - : Nordic Council for Wildlife Research (NKV). - 0909-6396 .- 1903-220X. ; 1, s. 1-10
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Recension (refereegranskat)abstract
- Goose management in Europe is faced by multiple challenges, as some species are declining and in need of conservation actions, while other populations have become very abundant, resulting in calls for increased harvest. Sweden has long-term series of harvest data and counts of breeding and autumn-staging geese. We used national data (indices) for greylag goose, bean goose and Canada goose to study shifts in temporal trends and correlative patterns, and to infer possible causal links between harvest and population trends. Our study provides an opportunity to guide management given the data collected within the present monitoring, as well as to suggest improvements for future data collection. The populations of greylag and Canada geese increased in Sweden 1979–2018, but this long-term trend included a recent decrease in the latter species. Bean goose breeding index decreased, whilst staging numbers and harvest varied with no clear long-term trend. For Canada goose, our analysis suggests that harvest may affect population growth negatively. For bean goose and greylag goose we could not detect any effect of harvest on autumn counts the following year. We find that the present data and analysis of coherence may suffice as basis for decisions for the current management situation in Sweden with its rather unspecific goals for greylag (very abundant) and Canada goose (invasive species) populations. However, for management of bean geese, with international concerns of over harvest, data lack crucial information. For future management challenges, with more explicit goals, for all goose species we advocate information that is more precise. Data such as hunting effort, age-structure of goose populations and mark–recapture data to estimate survival and population size, is needed to feed predictive population models guiding future Swedish and European goose management.
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| 3. |
- 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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| 4. |
- Strong, Emily A., et al.
(författare)
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Seeking greener pastures : crop selection by Greylag Geese (Anser anser) during the moulting season
- 2021
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Ingår i: Ornis Fennica. - : Finnish Omithological Soc. - 0030-5685. ; 98:1, s. 16-32
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Tidskriftsartikel (refereegranskat)abstract
- Over the last 40 years, many goose populations have recovered from historic lows and are now more numerous than ever. At the same time, geese have shifted from natural foraging habitats to securing most of their nutritional demands from agricultural fields, leading to crop damage and conflict with agriculture. We studied field use by Greylag Geese (Anser anser) in the agricultural landscape surrounding a main breeding and moulting lake in Sweden. From 2012 to 2016, weekly roadside surveys were conducted from May to July. Data were collected on goose numbers, crop type and sward height in agricultural fields. Using a compositional analysis, we demonstrate that Greylag Geese show a strong selection for ley and pasture fields compared to other crop types (rank order: ley/pasture > oat > barley > wheat > other crops). This selection was consistent across years and between pre- and post-moult. Aside from ley and pasture, no other croptypes were selected for, as they were used less than expected given their availability. Irrespective of crop type, geese foraged predominantly on short (0–10 cm) swards. The strong selection for ley and pasture may have been driven by higher nutritional quality of short, managed grass swards relative to other available foods. This suggests that during the summer grass fields may be more vulnerable to damage compared to other crop types. Our study provides a deeper understanding of the ecology of Greylag Geese, which may be used to inform management strategies focused on mitigating crop damage and alleviating conflict.
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