| 1. |
- Dessborn, Lisa, 1976-, et al.
(författare)
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Innate responses of mallard ducklings towards aerial, aquatic and terrestrial predators
- 2012
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Ingår i: Behaviour. - Leiden, Netherlands : Brill Academic Publishers. - 0005-7959 .- 1568-539X. ; 149:13-14, s. 1299-1317
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Tidskriftsartikel (refereegranskat)abstract
- Reproductive success in ducks is strongly influenced by predation on the breeding grounds. Ducklings are targeted by a range of terrestrial, aerial and aquatic predators, giving a strong selective advantage to individuals and broods that have effective ways to avoid predation. In experiments on naive mallard (Anas platyrhynchos) ducklings without an accompanying adult female we investigated the innate ability to identify and avoid threats at varying intensity from aerial, aquatic and terrestrial predators. Ducklings displayed increased vigilance in response to pre-recorded calls of predatory birds, representing a low level of threat. They did not react to visual and olfactory stimuli generated by motionless northern pike (Esox lucius). Neither did they show a strong response to caged American mink (Neovison vison) (visual and olfactory stimuli), although they avoided the area with the mink, indicating a certain level of recognition. High intensity threats were simulated by staging attacks from aerial (goshawk, Accipiter gentilis) and aquatic predators (northern pike). The aerial attack made ducklings dive and scatter under water, whereas the response to attack by pike was to run on the water and scatter in different directions. The lack of response to a ‘passive’ pike and the rather weak avoidance of mink indicate that olfactory cues are not as important in identifying a potential predatory threat by ducklings as are auditory cues. Visual cues appear to be of little importance unless they are combined with movement, and a clear response is only triggered when the intensity of predator threat is high. Mallard ducklings, thus, show an innate capacity to adjust anti-predator behaviour to different predator types and to threat intensity. Our study highlights the general trade-off between foraging needs and predator avoidance, but also second-order trade-offs in which innate avoidance behaviour towards one type of predator may increase predation risk from another.
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| 2. |
- Thulin, Carl-Gustaf, et al.
(författare)
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The impact of founder events and introductions on genetic variation in the muskox Ovibos moschatus in Sweden
- 2011
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Ingår i: Acta Theriologica. - : Springer Science and Business Media LLC. - 0001-7051 .- 2190-3743. ; 56:4, s. 305-314
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Tidskriftsartikel (refereegranskat)abstract
- The muskox Ovibos moschatus (Zimmerman 1780) is a specialised arctic mammal with a highly fragmented circumpolar distribution, with native populations in Canada and east Greenland and introduced populations in west Greenland, Alaska, Siberia and Eurasia. In 1971, five O. moschatus individuals from an introduced population in Norway migrated to Sweden. After a peak population of 36 individuals in the mid-1980s, the Swedish population now numbers seven individuals, making it vulnerable to both demographic and genetic stochasticity (i.e. inbreeding). Here, we analyse genetic variation among native and introduced populations of O. moschatus to evaluate the genetic effect of sequential founder events in this species. Our results show that genetic variation among native and introduced O. moschatus populations do not conform entirely to the expectations from sequential founder events, most likely because of random processes associated with introduction. In the Swedish population, a calf resulting from the mating of a wild cow and a captive Greenlandic bull contributes significantly to the current genetic variation. Thus, even a single outbreeding event may, at least momentarily, increase the genetic variation and potentially prevent inbreeding depression. Our results should aid the long-term preservation of O. moschatus in Sweden and Europe.
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| 3. |
- Adami, Johanna, et al.
(författare)
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Smoking and the risk of leukemia, lymphoma, and multiple myeloma (Sweden)
- 1998
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Ingår i: Cancer Causes and Control. - 0957-5243 .- 1573-7225. ; 9:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- While several epidemiologic studies have indicated a link between smoking and the risk of developing hematolymphoproliferative cancers (chiefly leukemias, lymphomas, and multiple myelomas), in particular myeloid leukemia, the role of tobacco in the etiology of these neoplasms remains unclear. To evaluate the potential impact of tobacco use on development of leukemia, lymphoma, and multiple myeloma, we conducted a cohort study of 334,957 Swedish construction workers using prospectively collected exposure-information with complete long-term follow-up. A total of 1,322 incident neoplasms occurred during the study period, 1971-91. We found no significant association between smoking status, number of cigarettes smoked, or duration of smoking and the risk of developing leukemias, lymphomas, or multiple myeloma. There was a suggestion of a positive association between smoking and the risk of developing Hodgkin's disease, although the rate ratios were not significantly elevated, except for young current smokers. No positive dose-risk trends emerged. Our study provides no evidence that smoking bears any major relationship to the occurrence of leukemias, non-Hodgkin's lymphomas, or multiple myeloma.
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| 4. |
- Aldahan, Ala, et al.
(författare)
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Iodine-129 enrichment in sediment of the Baltic Sea
- 2007
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Ingår i: Applied Geochemistry. - : Elsevier BV. - 0883-2927 .- 1872-9134. ; 22:3, s. 637-647
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Tidskriftsartikel (refereegranskat)abstract
- Sediments are an excellent archive for evaluation of time-series environmental contamination of water systems. Measurements of ultra-trace radioactive species, such as 129I, provide information for both chronologic calibration and anthropogenic emissions during the nuclear era. Here data are presented on 129I and other chemical parameters from two sediment cores collected in the Baltic Sea during 1997. The sediment sections have a relatively uniform grain size (clay–mud) and cover a period of about 50 a. Distribution of 129I in the sediment strongly relates to the liquid release records from the nuclear reprocessing facilities at Sellafield and La Hague. However, syn- and post-depositional alteration of organic matter at the sediment–water interface and within the sediment column may have contributed to slightly obliterating the anthropogenic 129I signals. Indication of Chernobyl-derived 129I occurs in the sediment profile, but is apparently overridden by the overwhelming flux from the nuclear reprocessing facilities. Although the record did not cover the pre-nuclear era (before 1945) sections, the ultra sensitive 129I profile provides a potential tool for relative dating and monitoring sources of water and sediment to the region.
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| 5. |
- Arnqvist, Goran, et al.
(författare)
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Falsk marknadsföring om hållbart skogsbruk
- 2022
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Ingår i: Svenska Dagbladet Debatt. - 1101-2412.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Dagens svenska skogsbruk är inte ekologiskt hållbart. Att saluföra det som hållbart är därför – för att tala klarspråk – falsk marknadsföring, skriver forskare.
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| 6. |
- Balint, Miklos, et al.
(författare)
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Environmental DNA time series in ecology
- 2018
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Ingår i: Trends in Ecology & Evolution. - London : Elsevier. - 0169-5347 .- 1872-8383. ; 33:12, s. 945-957
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Forskningsöversikt (refereegranskat)abstract
- Ecological communities change in time and space, but long-term dynamics at the century-to-millennia scale are poorly documented due to lack of relevant data sets. Nevertheless, understanding long-term dynamics is important for explaining present-day biodiversity patterns and placing conservation goals in a historical context. Here, we use recent examples and new perspectives to highlight how environmental DNA (eDNA) is starting to provide a powerful new source of temporal data for research questions that have so far been overlooked, by helping to resolve the ecological dynamics of populations, communities, and ecosystems over hundreds to thousands of years. We give examples of hypotheses that may be addressed by temporal eDNA biodiversity data, discuss possible research directions, and outline related challenges.
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| 7. |
- Bellard, Celine, et al.
(författare)
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Biotic and abiotic drivers of species loss rate in isolated lakes
- 2019
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Ingår i: Journal of Animal Ecology. - : WILEY. - 0021-8790 .- 1365-2656. ; 88:6, s. 881-891
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Tidskriftsartikel (refereegranskat)abstract
- Today, anthropogenic impacts are causing a serious crisis for global biodiversity, with rates of extinction increasing at an unprecedented rate. Extinctions typically occur after a certain delay, and understanding the mechanisms causing delays is a key challenge for both fundamental and applied perspectives. Here, we make use of natural experiments, the isolation of lakes by land uplift in Northern Scandinavia, to examine how yearly extinction rates are affected by time since isolation and a range of abiotic and biotic factors. In this aim, we adapted a model of delayed species loss within isolated communities to test the effects of time since isolation, area, pH, depth and the presence/absence of piscivores on extinction rates. As expected, we found that small and/or young lakes experience a higher annual rate of extinctions per species than larger and/or older ones. Compared to previous studies that were conducted for either young (few thousand years ago) or very old (>10,000 years ago) isolates, we demonstrated over a large and continuous temporal scales (50-5,000 years), similar relationship between extinction rates and age. We also show that extinction rates are modified by local environmental factors such as a strong negative effect of increasing pH. Our results urge for the need to consider the time since critical environmental changes occurred when studying extinction rates. In a wider perspective, our study demonstrates the need to consider extinction debts when modelling future effects of climate change, land-use changes or biological invasions on biodiversity.
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