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| 2. |
- Adamik, Peter, et al.
(författare)
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Barrier crossing in small avian migrants : individual tracking reveals prolonged nocturnal flights into the day as a common migratory strategy
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Over decades it has been unclear how individual migratory songbirds cross large ecological barriers such as seas or deserts. By deploying light-level geolocators on four songbird species weighing only about 12 g, we found that these otherwise mainly nocturnal migrants seem to regularly extend their nocturnal flights into the day when crossing the Sahara Desert and the Mediterranean Sea. The proportion of the proposed diurnally flying birds gradually declined over the day with similar landing patterns in autumn and spring. The prolonged flights were slightly more frequent in spring than in autumn, suggesting tighter migratory schedules when returning to breeding sites. Often we found several patterns for barrier crossing for the same individual in autumn compared to the spring journey. As only a small proportion of the birds flew strictly during the night and even some individuals might have flown non-stop, we suggest that prolonged endurance flights are not an exception even in small migratory species. We emphasise an individual’s ability to perform both diurnal and nocturnal migration when facing the challenge of crossing a large ecological barrier to successfully complete a migratory journey.
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| 21. |
- Arct, Aneta, et al.
(författare)
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Effects of elevated nest box temperature on incubation behaviour and offspring fitness-related traits in the Collared Flycatcher Ficedula albicollis
- 2022
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Ingår i: Journal of Ornithology. - : Springer Nature. - 2193-7192 .- 2193-7206. ; 163, s. 263-272
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Tidskriftsartikel (refereegranskat)abstract
- Ambient temperature experienced by an animal during development or subsequently as an adult can affect many aspects of its behaviour and life-history traits. In birds, egg incubation is a vital component of reproduction and parental care. Several studies have suggested that environmental factors (such as nest microclimate) can influence the ability of incubating parents to maintain suitable conditions for embryo development. Here, we manipulated the developmental conditions of embryos through a modification of nest box thermal microclimate to investigate female incubation behaviour and its impact on offspring fitness-related traits in a wild population of the Collared Flycatcher (Ficedula albicollis). The temperature in experimental nests was increased using a heat-pack placed under the roof of a nest box, resulting in an average temperature increase of 2.5 degrees C, which corresponds to projected climate change scenarios. We demonstrated that females from nests with elevated temperature spent less time in the nest box during egg incubation and had more off-bouts than females from control nests. Moreover, we found that offspring from the experimentally heated nests had larger body mass at fledging in comparison to the control ones. Our study indicates that nest microclimate during the incubation period affects female incubation behaviour and offspring quality, indicating that environmental variation in nest temperature early in ontogeny can have important and long-lasting fitness consequences.
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| 22. |
- Arct, Aneta, et al.
(författare)
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Parental genetic similarity and offspring performance in blue tits in relation to brood size manipulation
- 2019
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Ingår i: Ecology and Evolution. - : WILEY. - 2045-7758. ; 9:18, s. 10085-10091
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Tidskriftsartikel (refereegranskat)abstract
- In birds, as in many other taxa, higher genetic similarity of mates has long been known to reduce offspring fitness. To date, the majority of avian studies have focused on examination whether the genetic similarity of social mates predicts hatching success. Yet, increased genetic similarity of mates may also reduce offspring fitness during later life stages, including the nestling period and beyond. Here, we investigated whether parental genetic similarity influences offspring performance using data from free-living blue tits (Cyanistes caeruleus) collected across three breeding seasons. Additionally, we tested whether brood size manipulation affects the magnitude and direction of the relationship between genetic similarity of mates and offspring performance. Sixteen microsatellite markers were used to measure genetic similarity between biological parents. We found that the genetic similarity of parents negatively affects offspring immune response and this effect was independent of the experimental brood size manipulation.
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| 23. |
- Arct, Aneta, et al.
(författare)
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Temperature variability is associated with the occurrence of extrapair paternity in blue tits
- 2024
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Ingår i: Behavioral Ecology. - : Oxford University Press. - 1045-2249 .- 1465-7279. ; 35:1
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Tidskriftsartikel (refereegranskat)abstract
- In birds, extrapair paternity (EPP) constitutes an alternative mating strategy, with potentially important fitness consequences for both males and females and their offspring. Several factors have been identified that can influence the occurrence of EPP, but the role of environmental variability has so far received relatively little attention. Using long-term data set from a wild population of the blue tit (Cyanistes cearuleus), we assess the importance of ambient temperature in modulating the levels of extrapair paternity. Here, we showed that the variability of local thermal conditions affects the occurrence of EPP. Specifically, we found that the probability of EPP increased with rising variability in ambient temperature experienced by females prior to egg laying. This pattern is consistent with an idea of plastic female responses to unpredictable environments. Our results suggest that extrapair mating may represent an adaptive behavioral strategy to compensate for the potential negative effects of unstable environmental conditions.
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| 24. |
- Arct, Aneta, et al.
(författare)
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The interactive effect of ambient temperature and brood size manipulation on nestling body mass in blue tits : an exploratory analysis of a long-term study
- 2022
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Ingår i: Frontiers in Zoology. - : BioMed Central (BMC). - 1742-9994. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Relatively few studies have examined the interactive effects of ecological factors on physiological responses in wild animals. Nearly all of them have been short-term investigations that did not include experimental manipulations, limiting our ability to understand how climate change will affect natural populations. Using a 10-year brood size manipulation experiment in wild blue tits (Cyanistes caeruleus), we quantified the impact of weather conditions and brood competition on the body mass and structural size (tarsus length) of nestlings just prior to leaving the nest. Results We found that variation in nestling body mass on day 14 after hatching was explained by an interactive effect between average ambient temperature experienced during nestling period and brood size treatment. Specifically, in control broods nestling body mass was correlated with temperature in a non-linear manner (concave) with the vertex point (maximum body mass) at ca. 13 degrees C. In contrast, in enlarged broods nestling body mass permanently increased (also non-linearly) as temperature advanced. Conclusions Our results highlight the importance of considering the effects of brood rearing conditions alongside other environmental factors experienced during growth while investigating early-life environmental effects on body condition.
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| 25. |
- Bennett, G. F., et al.
(författare)
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TRYPANOSOMES OF SOME FENNOSCANDIAN BIRDS
- 1994
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Ingår i: Memórias do instituto Oswaldo Cruz. - 0074-0276 .- 1678-8060. ; 89:4, s. 531-537
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Tidskriftsartikel (refereegranskat)
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| 26. |
- Bonnet, Timothee, et al.
(författare)
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Genetic variance in fitness indicates rapid contemporary adaptive evolution in wild animals
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 376:6596, s. 1012-1016
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Tidskriftsartikel (refereegranskat)abstract
- The rate of adaptive evolution, the contribution of selection to genetic changes that increase mean fitness, is determined by the additive genetic variance in individual relative fitness. To date, there are few robust estimates of this parameter for natural populations, and it is therefore unclear whether adaptive evolution can play a meaningful role in short-term population dynamics. We developed and applied quantitative genetic methods to long-term datasets from 19 wild bird and mammal populations and found that, while estimates vary between populations, additive genetic variance in relative fitness is often substantial and, on average, twice that of previous estimates. We show that these rates of contemporary adaptive evolution can affect population dynamics and hence that natural selection has the potential to partly mitigate effects of current environmental change.
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| 27. |
- Both, C., et al.
(författare)
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Large-scale geographical variation confirms that climate change causes birds to lay earlier
- 2004
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Ingår i: Proceedings of the Royal Society of London Series B-Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 271:1549, s. 1657-1662
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Tidskriftsartikel (refereegranskat)abstract
- Advances in the phenology of organisms are often attributed to climate change, but alternatively, may reflect a publication bias towards advances and may be caused by environmental factors unrelated to climate change. Both factors are investigated using the breeding dates of 25 long-term studied populations of Ficedula flycatchers across Europe. Trends in spring temperature varied markedly between study sites, and across populations the advancement of laying date was stronger in areas where the spring temperatures increased more, giving support to the theory that climate change causally affects breeding date advancement.
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| 28. |
- Briedis, Martins, et al.
(författare)
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A full annual perspective on sex-biased migration timing in long-distance migratory birds
- 2019
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 286:1897
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Tidskriftsartikel (refereegranskat)abstract
- In many taxa, the most common form of sex-biased migration timing is protandry – the earlier arrival of males at breeding areas. Here we test this concept across the annual cycle of long-distance migratory birds. Using more than 350 migration tracks of small-bodied trans-Saharan migrants, we quantify differences in male and female migration schedules and test for proximate determinants of sex-specific timing. In autumn, males started migration about 2 days earlier, but this difference did not carry over to arrival at the non-breeding sites. In spring, males on average departed from the African non-breeding sites about 3 days earlier and reached breeding sites ca 4 days ahead of females. A cross-species comparison revealed large variation in the level of protandry and protogyny across the annual cycle. While we found tight links between individual timing of departure and arrival within each migration season, only for males the timing of spring migration was linked to the timing of previous autumn migration. In conclusion, our results demonstrate that protandry is not exclusively a reproductive strategy but rather occurs year-round and the two main proximate determinants for the magnitude of sex-biased arrival times in autumn and spring are sex-specific differences in departure timing and migration duration.
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| 29. |
- Briedis, Martins, et al.
(författare)
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Broad-scale patterns of the Afro-Palaearctic landbird migration
- 2020
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Ingår i: Global Ecology and Biogeography. - : WILEY. - 1466-822X .- 1466-8238. ; 29:4, s. 722-735
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Knowledge of broad-scale biogeographical patterns of animal migration is important for understanding ecological drivers of migratory behaviours. Here, we present a flyway-scale assessment of the spatial structure and seasonal dynamics of the Afro-Palaearctic bird migration system and explore how phenology of the environment guides long-distance migration.Location: Europe and Africa.Time period: 2009-2017.Major taxa studied: Birds.Methods: We compiled an individual-based dataset comprising 23 passerine and near-passerine species of 55 European breeding populations, in which a total of 564 individuals were tracked during migration between Europe and sub-Saharan Africa. In addition, we used remotely sensed primary productivity data (the normalized difference vegetation index) to estimate the timing of vegetation green-up in spring and senescence in autumn across Europe. First, we described how individual breeding and non-breeding sites and the migratory flyways link geographically. Second, we examined how the timing of migration along the two major Afro-Palaearctic flyways is tuned with vegetation phenology at the breeding sites.Results: We found the longitudes of individual breeding and non-breeding sites to be related in a strongly positive manner, whereas the latitudes of breeding and non-breeding sites were related negatively. In autumn, migration commenced ahead of vegetation senescence, and the timing of migration was 5-7 days earlier along the Western flyway compared with the Eastern flyway. In spring, the time of arrival at breeding sites was c. 1.5 days later for each degree northwards and 6-7 days later along the Eastern compared with the Western flyway, reflecting the later spring green-up at higher latitudes and more eastern longitudes.Main conclusions: Migration of the Afro-Palaearctic landbirds follows a longitudinally parallel leapfrog migration pattern, whereby migrants track vegetation green-up in spring but depart before vegetation senescence in autumn. The degree of continentality along migration routes and at the breeding sites of the birds influences the timing of migration on a broad scale.
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| 38. |
- Drobniak, Szymon M., et al.
(författare)
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Differential effects of steroid hormones on levels of broad-sense heritability in a wild bird : possible mechanism of environment x genetic variance interaction?
- 2022
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Ingår i: Heredity. - : Springer Nature. - 0018-067X .- 1365-2540. ; 128:1, s. 63-76
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Tidskriftsartikel (refereegranskat)abstract
- Genetic variation is one of the key concepts in evolutionary biology and an important prerequisite of evolutionary change. However, we know very little about processes that modulate its levels in wild populations. In particular, we still are to understand why genetic variances often depend on environmental conditions. One of possible environment-sensitive modulators of observed levels of genetic variance are maternal effects. In this study we attempt to experimentally test the hypothesis that maternally transmitted agents (e.g. hormones) may influence the expression of genetic variance in quantitative traits in the offspring. We manipulated the levels of steroid hormones (testosterone and corticosterone) in eggs laid by blue tits in a wild population. Our experimental setup allowed for full crossing of genetic and rearing effects with the experimental manipulation. We observed that birds treated with corticosterone exhibited a significant decrease in broad-sense genetic variance of tarsus length, and an increase in this component in body mass on the 2nd day post-hatching. Our study indicates, that maternally transmitted substances such as hormones may have measurable impact on the levels of genetic variance and hence, on the evolutionary potential of quantitative traits.
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| 39. |
- Drobniak, Szymon M., et al.
(författare)
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Habitat shapes diversity of gut microbiomes in a wild population of blue tits Cyanistes caeruleus
- 2022
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Ingår i: Journal of Avian Biology. - : John Wiley & Sons. - 0908-8857 .- 1600-048X. ; 2022:2
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Tidskriftsartikel (refereegranskat)abstract
- Microbiome constitutes an important axis of individual variation that, together with genes and the environment, influences an individual's physiology and fitness. Microbiomes are dependent not only on an individual's body condition but also on external factors, such as diet or stress levels, and as such can be involved into feedbacks between the external ecological factors and internal physiology. In our study, we used a wild population of blue tits Cyanistes caeruleus to investigate the impact of external habitat composition on the microbiome of adult birds. We hypothesized that - through differences in plant composition, potentially affecting diet complexity - habitat type may impact the diversity and structure of the gut microbiome. Blue tits breeding in dense deciduous forests tended to have more diverse microbiomes and be significantly different in terms of microbiome composition from birds breeding in open, sparsely forested hay meadows. Distinct study plots also tended to differ in a number of parameters describing microbiome diversity. We observed no microbiome differentiation according to individual characteristics such as sex or age. The study emphasizes that external environment is one of the important modulators of microbiome diversity and calls for more such studies in wild animal populations.
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| 42. |
- Fletcher, Kevin, et al.
(författare)
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Glucocorticoid response to both predictable and unpredictable challenges detected as corticosterone metabolites in collared flycatcher droppings
- 2018
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- In most vertebrate animals, glucocorticoid hormones are the chief mediators of homeostasis in response to ecological conditions and as they progress through their lifecycle. In addition, glucocorticoids are a major part of the stress response and stress induced elevations of the hormone can make it difficult to assess glucocorticoid secretion in response to changes in life-stage and current environmental conditions in wild animals. Particularly when quantifying circulating levels of glucocorticoids in the blood which fluctuate rapidly in response to stress. An alternative method of quantifying glucocorticoids is as hormone metabolites in faeces or urine giving a historical sample related to the gut passage time and urinary tract that is less sensitive to stressful events which cause spikes in the circulating hormone level. Although the concentration of glucocorticoid metabolites are influenced by faecal mass thereby potentially affecting any differences in hormone metabolites detected amongst samples. In the present study, we aimed to detect changes in levels of corticosterone, the primary bird glucocorticoid, in relation to the phase of reproduction, in a breeding population of collared flycatchers by sampling corticosterone metabolites in droppings. We also tested how corticosterone metabolite concentrations were affected by ambient temperature and related to body condition in adult birds. Our results indicate that the upregulation of corticosterone between incubation and nestling feeding in female birds is crucial for successful reproduction in this species. Also, females appear to downregulate corticosterone during incubation in response to lower ambient temperature and poorer body condition. Our results did not indicate a relationship between dropping mass and corticosterone metabolite concentrations, which suggests that our findings were linked to the regulation of corticosterone in response to predictable and unpredictable challenges.
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| 43. |
- Fletcher, Kevin, et al.
(författare)
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Importance of infection of haemosporidia blood parasites during different life history stages for long-term reproductive fitness of collared flycatchers
- 2019
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Ingår i: Journal of Avian Biology. - : John Wiley & Sons. - 0908-8857 .- 1600-048X. ; 50:8
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Tidskriftsartikel (refereegranskat)abstract
- The interaction between birds and haemosporidia blood parasites is a well-used system in the study of parasite biology. However, where, when and how parasites are transmitted is often unclear and defining parasite transmission dynamics is essential because of how they influence parasite-mediated costs to the host. In this study, we used cross-sectional and longitudinal data taken from a collared flycatcher Ficedula albicollis population to investigate the temporal dynamics of haemosporidia parasite infection and parasite-mediated costs to host fitness. We investigated host-parasite interactions starting at the nestling stage of the bird's life-cycle and then followed their progress over three breeding attempts to quantify their fitness - measured as the number of offspring they produced that recruited back into the breeding population. We found that the majority of haemosporidia blood parasite infections occurred within the first year of life and that the most common parasite lineages that infected the breeding population also infected juvenile birds in the natal environment. Moreover, our findings suggest that collared flycatcher nestlings in poorer condition could be at a higher risk of haemosporidia blood parasite infection. In this study, only female and not male bird fitness was adversely affected by parasite infection and the cost of infection on female fitness depended on the timing of transmission. In conclusion, our study indicates that in collared flycatchers, early-life is potentially important for many of the interactions with haemosporidia parasite lineages, and evidence of parasite-mediated costs to fitness suggest that these parasites may have influenced the host population dynamics.
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