| 1. |
- Gsell, Alena S., et al.
(författare)
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Environmental refuges from disease in host–parasite interactions under global change
- 2023
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 104:4
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Tidskriftsartikel (refereegranskat)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.
(författare)
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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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Ingår i: Evolution. - : Society for the Study of Evolution. - 0014-3820 .- 1558-5646. ; 52:4, s. 1169-1184
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Tidskriftsartikel (refereegranskat)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.
(författare)
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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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Ingår i: Global Change Biology. - Oxford : Blackwell Scientific. - 1354-1013 .- 1365-2486. ; 15:5, s. 1057-1071
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Tidskriftsartikel (refereegranskat)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.
(författare)
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Kin clustering in barnacle geese : familiarity or phenotype matching?
- 2002
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Ingår i: Behavioral Ecology. - : Oxford University Press. - 1045-2249 .- 1465-7279. ; 13:6, s. 786-790
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Tidskriftsartikel (refereegranskat)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.
(författare)
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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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Ingår i: Die Vogelwelt : Zeitschrift für Vogelkunde und Vogelschutz. - : Duncker & Humblot. - 0042-7993. ; 129, s. 244-252
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Tidskriftsartikel (refereegranskat)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.
(författare)
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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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Ingår i: Eurosurveillance. - 1025-496X .- 1560-7917. ; 21:38, s. 11-21
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Tidskriftsartikel (refereegranskat)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. |
- Jiguet, Frederic, et al.
(författare)
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Bird population trends are linearly affected by climate change along species thermal ranges
- 2010
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Ingår i: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954. ; 277:1700, s. 3601-3608
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Tidskriftsartikel (refereegranskat)abstract
- Beyond the effects of temperature increase on local population trends and on species distribution shifts, how populations of a given species are affected by climate change along a species range is still unclear. We tested whether and how species responses to climate change are related to the populations locations within the species thermal range. We compared the average 20 year growth rates of 62 terrestrial breeding birds in three European countries along the latitudinal gradient of the species ranges. After controlling for factors already reported to affect bird population trends (habitat specialization, migration distance and body mass), we found that populations breeding close to the species thermal maximum have lower growth rates than those in other parts of the thermal range, while those breeding close to the species thermal minimum have higher growth rates. These results were maintained even after having controlled for the effect of latitude per se. Therefore, the results cannot solely be explained by latitudinal clines linked to the geographical structure in local spring warming. Indeed, we found that populations are not just responding to changes in temperature at the hottest and coolest parts of the species range, but that they show a linear graded response across their European thermal range. We thus provide insights into how populations respond to climate changes. We suggest that projections of future species distributions, and also management options and conservation assessments, cannot be based on the assumption of a uniform response to climate change across a species range or at range edges only.
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| 8. |
- Jeugd, Henk van der
(författare)
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Life history decisions in a changing environment : A long-term study of a temperate barnacle goose population
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis shows that climate and increasing population density have profound effects on survival, age at first reproduction, and natal dispersal in a rapidly increasing temperate barnacle goose Branta leucopsis population on Gotland, Sweden.Colony size was found to be the most important fitness-determinant because of strong density-dependent effects on reproduction. The amount of rain during the breeding season influenced the food supply of growing geese, resulting in considerable differences in weight and structural body size among birth-cohorts. These differences, in turn, affected pre-breeding survival Thus, members of some cohorts had a much higher probability of surviving to their first breeding attempt than members of other cohorts. Structural body size of cohorts declined rapidly during the initial phases of colony growth, and subsequent recruitment to the breeding population of these cohorts caused the mean body size of breeding birds to decline slowly but constantly during the study. Since large females produced more young, and body size was heritable, an increase in mean body size was expected, but density-dependent effects on growth and final structural body size prevented such a microevolutionary response to selection.Age at first reproduction increased with increasing colony size, especially in females. This was caused by an increased competition for space, making it harder for young individuals to establish a territory, and not by deteriorating body condition due to-increased competition for food. Male natal dispersal rate increased, but female natal dispersal rates remained very low throughout the study, suggesting high benefits of philopatry in females. Large males were more likely to disperse than small ones, because only large males coulddeal with the costs that were associated with settling in an unfamiliar environment. Barnacle geese sampled potential mates by engaging in temporary trial liaisons. One-year-old birds had higher status when accompanied by a trial partner, and females that were often in the company of older trial partners early in life produced more young. Finally, birds that found their final partner early also started breeding early in life.
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| 9. |
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| 10. |
- Kampichler, Christian, et al.
(författare)
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Temporal dynamics of bird community composition: an analysis of baseline conditions from long-term data
- 2014
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 175:4, s. 1301-1313
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Tidskriftsartikel (refereegranskat)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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