| 1. |
- Gsell, Alena S., et al.
(author)
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Environmental refuges from disease in host–parasite interactions under global change
- 2023
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In: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 104:4
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Journal article (peer-reviewed)abstract
- The physiological performance of organisms depends on their environmental context, resulting in performance–response curves along environmental gradients. Parasite performance–response curves are generally expected to be broader than those of their hosts due to shorter generation times and hence faster adaptation. However, certain environmental conditions may limit parasite performance more than that of the host, thereby providing an environmental refuge from disease. Thermal disease refuges have been extensively studied in response to climate warming, but other environmental factors may also provide environmental disease refuges which, in turn, respond to global change. Here, we (1) showcase laboratory and natural examples of refuges from parasites along various environmental gradients, and (2) provide hypotheses on how global environmental change may affect these refuges. We strive to synthesize knowledge on potential environmental disease refuges along different environmental gradients including salinity and nutrients, in both natural and food-production systems. Although scaling up from single host–parasite relationships along one environmental gradient to their interaction outcome in the full complexity of natural environments remains difficult, integrating host and parasite performance–response can serve to formulate testable hypotheses about the variability in parasitism outcomes and the occurrence of environmental disease refuges under current and future environmental conditions.
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| 2. |
- Larsson, Kjell, et al.
(author)
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Body size declines despite positive directional selection on heritable size traits in a barnacle goose population
- 1998
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In: Evolution. - : Society for the Study of Evolution. - 0014-3820 .- 1558-5646. ; 52:4, s. 1169-1184
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Journal article (peer-reviewed)abstract
- Analyses of more than 2000 marked barnacle geese (Branta leucopsis) in the largest Baltic colony, Sweden, showed that structurally large females generally produced larger clutches and larger eggs, hatched their broods earlier in the season, and produced more and heavier young than smaller females. In males, the corresponding relationships between reproductive parameters and structural body size were weaker or nonsignificant. Because structural body size traits have previously been found to be significantly heritable and positively genetically correlated, an increase in mean structural body size of individuals as a response to selection might have been expected. By contrast, we found that the mean adult head length and mean adult tarsus length decreased significantly in the largest colony by approximately 0.7 and 0.5 standard deviations, respectively, in both males and females during the 13-year study period. Environmental factors, such as the amount of rain in different years, were found to affect the availability of high-quality food for growing geese. As a consequence of this temporal variability in the availability of high-quality food, the mean adult structural body size of different cohorts differed by up to 1.3 standard deviations. Comparisons of mean body size of cohorts born in different colonies suggest that the most likely explanation for the body-size decline in the main study colony is that a density-dependent process, which mainly was in effect during the very early phase of colony growth, negatively affected juvenile growth and final size. We conclude that large environmental effects on growth and final structural body size easily can mask microevolutionary responses to selection. Analyses of environmental causes underlying temporal and spatial body size variation should always be considered in the reconstruction and prediction of evolutionary changes in natural populations.
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| 3. |
- Larsson, Kjell, 1958-, et al.
(author)
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Keeping up with early springs : rapid range expansion in an avian herbivore incurs a mismatch between reproductive timing and food supply
- 2009
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In: Global Change Biology. - Oxford : Blackwell Scientific. - 1354-1013 .- 1365-2486. ; 15:5, s. 1057-1071
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Journal article (peer-reviewed)abstract
- Within three decades, the barnacle goose population wintering on the European mainland has dramatically increased in numbers and extended its breeding range. The expansion has occurred both within the Arctic as well as by the colonization of temperate areas. Studies of performance of individuals in expanding populations provide information on how well species can adapt to novel environments and global warming. We, therefore, studied the availability of high quality food as well as timing of reproduction, wing moult, fledgling production and postfledging survival of individually marked geese in three recently established populations: one Arctic (Barents Sea) and two temperate (Baltic, North Sea). In the Barents Sea population, timing of hatching was synchronized with the peak in food availability and there was strong stabilizing selection. Although birds in the Baltic and North Sea populations bred 6–7 weeks earlier than Arctic birds, timing of hatching was late in relation to the peak in food availability, and there was moderate to strong directional selection for early breeding. In the Baltic, absolute timing of egg laying advanced considerably over the 20-year study period, but advanced little relative to spring phenology, and directional selection on lay date increased over time. Wing moult of adults started only 2–4 weeks earlier in the temperate populations than in the Arctic. Synchronization between fledging of young and end of wing moult decreased in the temperate populations. Arctic-breeding geese may gradually accumulate body stores from the food they encounter during spring migration, which allows them to breed relatively early and their young to use the peak of the Arctic food resources. By contrast, temperate-breeding birds are not able to acquire adequate body stores from local resources early enough, that is before the quality of food for their young starts to decrease. When global temperatures continue to rise, Arctic-breeding barnacle geese might encounter similar problems.
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| 4. |
- Larsson, Kjell, 1958-, et al.
(author)
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Kin clustering in barnacle geese : familiarity or phenotype matching?
- 2002
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In: Behavioral Ecology. - : Oxford University Press. - 1045-2249 .- 1465-7279. ; 13:6, s. 786-790
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Journal article (peer-reviewed)abstract
- We investigated the settling pattern of barnacle geese Branta leucopsis that returned to breed in their natal colony. Females nested close to their parents and sisters, but settling of males conformed to a random pattern. The apparent preference for breeding close to kin in females could be a by-product of extreme philopatry to the natal nest site. However, sisters also nested close to each other when settling on a different island than the one where their parents bred, pointing at a genuine preference for breeding close to kin. Females only nested close to sisters born in the same year (i.e., sisters that they had been in close contact with). This suggests that the clustering of female kin in barnacle geese does not result from phenotype matching. We did not detect any direct benefits of settling close to birth site or kin, but the analyses lacked power to detect small benefits of proximity to kin given the many other factors that may influence breeding success. Colonially breeding birds share characteristics that are generally believed to promote the evolution of cooperation, yet kin clustering and kin selection have been little studied in this group. Future research should be directed to studying the possible roles of kin clustering and kin selection in the evolution of coloniality.
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| 5. |
- Larsson, Kjell, 1958-, et al.
(author)
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Newly established breeding sites of the barnacle Goose branta leucopsis in North-western Europe - an overview of breeding habitats and colony development
- 2008
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In: Die Vogelwelt : Zeitschrift für Vogelkunde und Vogelschutz. - : Duncker & Humblot. - 0042-7993. ; 129, s. 244-252
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Journal article (peer-reviewed)abstract
- Traditional breeding grounds of the Russian Barnacle Goose population are at the Barents Sea in the Russian Arctic. During the last decades, the population increased and expanded the breeding area by establishing new breeding colonies at lower latitudes. Breeding numbers outside arctic Russia amounted to about 12,000 pairs in 2005. By means of a questionnaire, information about breeding habitat characteristics and colony size, colony growth and goose density were collected from breeding areas outside Russia. This paper gives an overview about the new breeding sites and their development in Finland, Estonia, Sweden, Denmark, Germany, The Netherlands and Belgium. Statistical analyses showed significant differences in habitat characteristics and population parameters between North Sea and Baltic breeding sites. Colonies at the North Sea are growing rapidly, whereas in Sweden the growth has levelled off in recent years. In Estonia numbers are even decreasing. On the basis of their breeding site choice, the flyway population of Barnacle Geese traditionally breeding in the Russian Arctic can be divided into three sub-populations: the Barents Sea population, the Baltic population and the North Sea population. The populations differ not only in habitat use but also in breeding biology.
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| 6. |
- Poen, Marjolein J, et al.
(author)
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Lack of virological and serological evidence for continued circulation of highly pathogenic avian influenza H5N8 virus in wild birds in the Netherlands, 14 November 2014 to 31 January 2016.
- 2016
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In: Eurosurveillance. - 1025-496X .- 1560-7917. ; 21:38, s. 11-21
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Journal article (peer-reviewed)abstract
- In 2014, H5N8 clade 2.3.4.4 highly pathogenic avian influenza (HPAI) viruses of the A/Goose/Guangdong/1/1996 lineage emerged in poultry and wild birds in Asia, Europe and North America. Here, wild birds were extensively investigated in the Netherlands for HPAI H5N8 virus (real-time polymerase chain reaction targeting the matrix and H5 gene) and antibody detection (haemagglutination inhibition and virus neutralisation assays) before, during and after the first virus detection in Europe in late 2014. Between 21 February 2015 and 31 January 2016, 7,337 bird samples were tested for the virus. One HPAI H5N8 virus-infected Eurasian wigeon (Anas penelope) sampled on 25 February 2015 was detected. Serological assays were performed on 1,443 samples, including 149 collected between 2007 and 2013, 945 between 14 November 2014 and 13 May 2015, and 349 between 1 September and 31 December 2015. Antibodies specific for HPAI H5 clade 2.3.4.4 were absent in wild bird sera obtained before 2014 and present in sera collected during and after the HPAI H5N8 emergence in Europe, with antibody incidence declining after the 2014/15 winter. Our results indicate that the HPAI H5N8 virus has not continued to circulate extensively in wild bird populations since the 2014/15 winter and that independent maintenance of the virus in these populations appears unlikely.
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| 7. |
- Kampichler, Christian, et al.
(author)
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Temporal dynamics of bird community composition: an analysis of baseline conditions from long-term data
- 2014
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In: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 175:4, s. 1301-1313
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Journal article (peer-reviewed)abstract
- Numerous anthropogenic activities threaten the biodiversity found on earth. Because all ecological communities constantly experience temporal turnover due to natural processes, it is important to distinguish between change due to anthropogenic impact and the underlying natural rate of change. In this study, we used data sets on breeding bird communities that covered at least 20 consecutive years, from a variety of terrestrial ecosystems, to address two main questions. (1) How fast does the composition of bird communities change over time, and can we identify a baseline of natural change that distinguishes primeval systems from systems experiencing varying degrees of human impact? (2) How do patterns of temporal variation in composition vary among bird communities in ecosystems with different anthropogenic impacts? Time lag analysis (TLA) showed a pattern of increasing rate of temporal compositional change from large-scale primeval systems to disturbed and protected systems to distinctly successional systems. TLA slopes of < 0.04 were typical for breeding bird communities with natural turnover, while communities subjected to anthropogenic impact were characterised by TLA slopes of > 0.04. Most of the temporal variability of breeding bird communities was explained by slow changes occurring over decades, regardless of the intensity of human impact. In most of the time series, medium- and short-wave periodicity was not detected, with the exception of breeding bird communities subjected to periodic pulses (e.g. caterpillar outbreaks causing food resource peaks).
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| 8. |
- Larsson, Kjell, 1958-, et al.
(author)
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Colony kin structure and host-parasite relatedness in the barnacle goose
- 2009
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In: Molecular Ecology. - Oxford : Blackwell Science. - 0962-1083 .- 1365-294X. ; 18:23, s. 4955-4963
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Journal article (peer-reviewed)abstract
- Conspecific brood parasitism (CBP), females laying eggs in the nest of other 'host' females of the same species, is a common alternative reproductive tactic among birds. For hosts there are likely costs of incubating and rearing foreign offspring, but costs may be low in species with precocial chicks such as waterfowl, among which CBP is common. Waterfowl show strong female natal philopatry, and spatial relatedness among females may influence the evolution of CBP. Here we investigate fine-scale kin structure in a Baltic colony of barnacle geese, Branta leucopsis, estimating female spatial relatedness using protein fingerprints of egg albumen, and testing the performance of this estimator in known mother-daughter pairs. Relatedness was significantly higher between neighbour females (nesting ≤ 40 metres from each other) than between females nesting farther apart, but there was no further distance trend in relatedness. This pattern may be explained by earlier observations of females nesting close to their mother or brood sisters, even when far from the birth nest. Hosts and parasites were on average not more closely related than neighbour females. In 25 of 35 sampled parasitized nests, parasitic eggs were laid after the host female finished laying, too late to develop and hatch. Timely parasites, laying eggs in the host's laying sequence, had similar relatedness to hosts as that between neighbours. Females laying late parasitic eggs tended to be less related to the host, but not significantly so. Our results suggest that CBP in barnacle geese might represent different tactical life-history responses.
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| 9. |
- Larsson, Kjell, et al.
(author)
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Continuing growth of the Baltic barnacle goose population : Number of individuals and reproductive success in different colonies
- 1997
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In: Research on arctic geese. - : Norsk Polarinstitutt. - 8276661548 ; , s. 213-219
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Conference paper (peer-reviewed)abstract
- The Baltic barnacle goose population increased rapidly after 1971, when the first breeding attempt was observed off the eastern coast of Gotland, Sweden. In 1997, about 3,990 pairs bred along the Baltic coast in Sweden, western Estonia and southern Finland. The majority of these pairs, about 3,490 pairs, were found breeding in colonies along the eastern coasts of Gotland and Oland, Sweden. The total population size at the end of July in 1997 was estimated to be approximately 17,000 individuals. The production of fledged young per breeding pair was negatively related to the size of colonies, although the production varied greatly among different colonies. In 1997, the largest Baltic colony hosted more than 50% of the total number of breeding pairs but produced less than 15% of the total number of fledged young. This finding points out the need to consider different colonies as separate demographic units when studying regulation processes in populations of colonially breeding geese. In the future, we find it most probable that the Baltic population will continue to increase and that new colonies will be established. We also expect that the number of Baltic barnacle geese eventually will be limited by the availability of predator-safe grazing grounds with short, protein rich grass which families with newly hatched goslings are dependent on.
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| 10. |
- Larsson, Kjell, 1958-, et al.
(author)
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Nest parasitism in the barnacle goose : evidence from protein fingerprinting and microsatellites
- 2009
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In: Animal Behaviour. - London : Academic Press. - 0003-3472 .- 1095-8282. ; 78:1, s. 167-174
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Journal article (peer-reviewed)abstract
- Geese are often seen as one of nature's best examples of monogamous relationships, and many social pairs stay together for life. However, when parents and young are screened genetically, some chicks do not match their social parents. Although this has often been explained as adoption of foreign young after hatching, conspecific nest parasitism is another possibility. We used nondestructive egg albumen sampling and protein fingerprinting to estimate the frequency and success of nest parasitism in a Baltic Sea population of barnacle geese, Branta leucopsis. Among the 86 nests for which we had the most complete information, 36% were parasitized, and 12% of the eggs were parasitic. Almost 80% of the parasitic eggs were laid after the host began incubation. Hatching of these eggs was limited to the few cases where the host female incubated longer than normally because her own eggs failed to hatch. Conspecific nest parasitism in this population therefore seems mainly to be an alternative reproductive tactic of lower fitness than normal nesting. Comparison with DNA profiling of chicks (with 10–14 microsatellites) and other evidence confirmed the suitability of protein fingerprinting for analysis of nest parasitism. It can often provide more data than microsatellites, if eggs are albumen-sampled soon after being laid, before most losses occur.
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