| 1. |
- 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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| 2. |
- Åkesson, Susanne, et al.
(författare)
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Autumn migratory orientation and route choice in early and late dunlins Calidris alpina captured at a stopover site in Alaska
- 2021
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Ingår i: Biology open. - : The Company of Biologists Ltd. - 2046-6390. ; 10:4, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the migratory orientation of early and late captured dunlins, Calidris alpina, by recording their migratory activity in circular orientation cages during autumn at a staging site in southwest Alaska and performed route simulations to the wintering areas. Two races of dunlins breeding in Alaska have different wintering grounds in North America (Pacific Northwest), and East Asia. Dunlins caught early in autumn (presumably Calidris alpina pacifica) oriented towards their wintering areas (east-southeast; ESE) supporting the idea that they migrate nonstop over the Gulf of Alaska to the Pacific Northwest. We found no difference in orientation between adult and juveniles, nor between fat and lean birds or under clear and overcast skies demonstrating that age, energetic status and cloud cover did not affect the dunlins' migratory orientation. Later in autumn, we recorded orientation responses towards south-southwest suggesting arrival of the northern subspecies Calidris alpina arcticola at our site. Route simulations revealed multiple compass mechanisms were compatible with the initial direction of early dunlins wintering in the Pacific Northwest, and for late dunlins migrating to East Asia. Future high-resolution tracking would reveal routes, stopover use including local movements and possible course shifts during migration from Alaska to wintering sites on both sides of the north Pacific Ocean.
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| 3. |
- Massa, Edoardo, et al.
(författare)
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Tardigrades of Kristianstads Vattenrike biosphere reserve with description of four new species from Sweden
- 2021
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Ingår i: Scientific Reports. - 2045-2322. ; 11:1, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Kristianstads Vattenrike Biosphere Reserve [KVBR] is a UNESCO designated area of Sweden possessing high biological value. Although several studies on tardigrades inhabiting Sweden havebeen performed, the KVBR area has been neglected. The current study investigates the tardigrade fauna of five areas of the biosphere reserve and includes 34 samples of different substrates analysed quantitatively and qualitatively. In total, 33 species of tardigrades were found in the samples, including 22 new records for the Skåne region, 15 new records for Sweden, and four species new to science. Mesobiotus emiliae sp. nov., Xerobiotus gretae sp. nov., Itaquascon magnussoni sp. nov., and Thulinius gustavi sp. nov. were described with an integrative approach (when possible) using morphological characters (light, electron scanning, and confocal laser scanning microscopies) and molecular markers (ITS2, 18S, 28S, cox1). A new protocol to increase morphological data was developed recovering mounted specimens within old slides for SEM analysis. Emended diagnoses for the genus Itaquascon and the transfer of Platicrista itaquasconoide to the genus Meplitumen are proposed. This study enriches the knowledge of the tardigrade biodiversity both within the KVBR and in Sweden and contributes to the rapidly increasing number of tardigrade species reported worldwide. The 33 species identified in the KVBR area represents 28% of all water bear species found in Sweden so far. The restricted study areas and limited number of samples collected suggests that the KVBR is very rich of tardigrades.
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| 4. |
- Jönsson, Ingemar K., 1959-
(författare)
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Tardigrades : evolutionary explorers in extreme environments
- 2020. - 1
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Ingår i: Extremophiles as astrobiological models. - Beverly : Scrivener Publishing LLC. - 9781119593096 - 9781119591689 ; , s. 255-274
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Tardigrades have long been recognized for their ability to survive the most extreme environmental conditions. In particular, the widespread ability of tardigrades to dehydrate and enter a state ofarrested metabolism (cryptobiosis) has allowed these aquatic animals to persist in habitats regularly deprived of water. The evolutionary strategy to allow metabolic arrest during periods of hostile conditionshas several advantages, including arrest of the biological clock and energy consumption, but since all cryptobiotic animal taxa have very small body size there must be physical or physiological constraints preventing this strategy to evolve in larger animals. Our understanding of the molecular mechanisms of cryptobiotic tardigrades has improved considerably over the last decade, much due to the genome and transcriptome sequencing of some species. Although we are still far from a comprehensive understanding of how tardigrades maintain cellular structure under complete dehydration, it is clear that multiple molecular mechanisms with carbohydrates and proteins are involved, and that different adaptive mechanisms have evolved within tardigrades. Based on their documented tolerances, tardigrades made their entrance into astrobiology with the FOTON-M3 mission in 2007, and were the first animals to survive a combined exposure to space vacuum, cosmic radiation and UV radiation. With their ancient adaptations for coping with environmental extremes, tardigrades are excellent animals for studies of how early metazoan life evolved, and for understanding the constraints of cryptobiotic adaptations. Most tardigrades do not fit within the traditional definition of extremophiles, but rather belong to the category of extremotolerant organisms, surviving extreme conditions but with optimal performance under more normal environmental conditions. However, tardigrades have been reported from some permanently extreme environments, such as deep sea and hot and radioactive springs, and more studies of these populations would be of great interest.
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