| 1. |
- Brlík, V, et al.
(författare)
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Survival fluctuation is linked to precipitation variation during staging in a migratory shorebird
- 2022
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Understanding how weather conditions affect animal populations is essential to foresee population changes in times of global climate shifts. However, assessing year-round weather impacts on demographic parameters is hampered in migratory animals due to often unknown occurrence in space and time. We addressed this by coupling tracking and weather data to explain extensive variation in apparent survival across 19 years in a northern European population of little ringed plovers (Charadrius dubius). Over 90% (n=21) of tracked individuals followed migration routes along the Indo-European flyway to south India. Building on capture–recapture histories of nearly 1400 individuals, we found that between-year variation in precipitation during post-breeding staging in northern South Asia explained 47% of variation in apparent adult survival. Overall, the intensity of the monsoon in South Asia explained 31–33% of variability in apparent survival. In contrast, weather conditions in breeding, final non-breeding and pre-breeding quarters appeared less important in this species. The integration of multi-source data seems essential for identifying key regions and periods limiting population growth, for forecasting future changes and targeting conservation efforts.
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| 2. |
- Hsu, B. Y., et al.
(författare)
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Maternally transferred thyroid hormones and life-history variation in birds
- 2022
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Ingår i: Journal of Animal Ecology. - : Wiley. - 0021-8790 .- 1365-2656. ; 91:7, s. 1489-1506
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Tidskriftsartikel (refereegranskat)abstract
- In vertebrates, thyroid hormones (THs) play an important role in the regulation of growth, development, metabolism, photoperiodic responses and migration. Maternally transferred THs are important for normal early phase embryonic development when embryos are not able to produce endogenous THs. Previous studies have shown that variation in maternal THs within the physiological range can influence offspring phenotype. Given the essential functions of maternal THs in development and metabolism, THs may be a mediator of life-history variation across species. We tested the hypothesis that differences in life histories are associated with differences in maternal TH transfer across species. Using birds as a model, we specifically tested whether maternally transferred yolk THs covary with migratory status, developmental mode and traits related to pace-of-life (e.g. basal metabolic rate, maximum life span). We collected un-incubated eggs (n = 1-21 eggs per species, median = 7) from 34 wild and captive bird species across 17 families and six orders to measure yolk THs [both triiodothyronine (T3) and thyroxine (T4)], compiled life-history trait data from the literature and used Bayesian phylogenetic mixed models to test our hypotheses. Our models indicated that both concentrations and total amounts of the two main forms of THs (T3 and T4) were higher in the eggs of migratory species compared to resident species, and total amounts were higher in the eggs of precocial species, which have longer prenatal developmental periods, than in those of altricial species. However, maternal yolk THs did not show clear associations with pace-of-life-related traits, such as fecundity, basal metabolic rate or maximum life span. We quantified interspecific variation in maternal yolk THs in birds, and our findings suggest higher maternal TH transfer is associated with the precocial mode of development and migratory status. Whether maternal THs represent a part of the mechanism underlying the evolution of precocial development and migration or a consequence of such life histories is currently unclear. We therefore encourage further studies to explore the physiological mechanisms and evolutionary processes underlying these patterns.
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| 3. |
- Pakanen, Veli Matti, et al.
(författare)
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Between-patch natal dispersal declines with increasing natal patch size and distance to other patches in the endangered Southern Dunlin Calidris alpina schinzii
- 2017
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Ingår i: Ibis. - : Wiley. - 1474-919X .- 0019-1019. ; 159:3, s. 611-622
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Tidskriftsartikel (refereegranskat)abstract
- Natal dispersal has profound consequences for populations through the movement of individuals and genes. Habitat fragmentation reduces structural connectivity by decreasing patch size and increasing isolation, but understanding of how this impacts dispersal and the functional connectivity of landscapes is limited because many studies are constrained by the size of the study areas or sample sizes to accurately capture natal dispersal. We quantified natal dispersal probability and natal dispersal distances in a small migratory shorebird, the Southern Dunlin Calidris alpina schinzii, with data from two extensively monitored endangered metapopulations breeding in Sweden and Finland. In both metapopulations philopatry was strong, with individuals returning to or close to their natal patches more often than expected by chance, consistent with the patchy distribution of their breeding habitat. Dispersal probabilities were lower and dispersal distances were shorter in Sweden. These results provide a plausible explanation for the observed inbreeding and population decline of the Swedish population. The differences between Sweden and Finland were explained by patch-specific differences. Between-patch dispersal decreased with increasing natal patch size and distance to other patches. Our results suggest that reduced connectivity reduces movements of the philopatric Dunlin, making it vulnerable to the effects of inbreeding. Increasing connectivity between patches should thus be one of the main goals when planning future management. This may be facilitated by creating a network of suitably sized patches (20–100ha), no more than 20km apart from each other, from existing active patches that may work as stepping stones for movement, and by increasing nest success and pre-fledging survival in small patches.
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| 4. |
- Pakanen, Veli Matti, et al.
(författare)
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Different ultimate factors define timing of breeding in two related species
- 2016
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:9
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Tidskriftsartikel (refereegranskat)abstract
- Correct reproductive timing is crucial for fitness. Breeding phenology even in similar species can differ due to different selective pressures on the timing of reproduction. These selection pressures define species' responses to warming springs. The temporal match-mismatch hypothesis suggests that timing of breeding in animals is selected to match with food availability (synchrony). Alternatively, time-dependent breeding success (the date hypothesis) can result from other seasonally deteriorating ecological conditions such as intra- or interspecific competition or predation.We studied the effects of two ultimate factors on the timing of breeding, synchrony and other time-dependent factors (time-dependence), in sympatric populations of two related forest-dwelling passerine species, the great tit (Parus major) and the willow tit (Poecile montanus) by modelling recruitment with long-termcapture-recapture data.We hypothesized that these two factors have different relevance for fitness in these species.We found that local recruitment in both species showed quadratic relationships with both time-dependence and synchrony. However, the importance of these factors was markedly different between the studied species. Caterpillar food played a predominant role in predicting the timing of breeding of the great tit. In contrast, for the willow tit time-dependence modelled as timing in relation to conspecifics was more important for local recruitment than synchrony. High caterpillar biomass experienced during the pre- and postfledging periods increased local recruitment of both species. These contrasting results confirmthat these species experience different selective pressures upon the timing of breeding, and hence responses to climate change may differ. Detailed information about life-history strategies is required to understand the effects of climate change, even in closely related taxa. The temporal match-mismatch hypothesis should be extended to consider subsequent critical periods when food needs to be abundantly available.
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| 5. |
- Pakanen, Veli-Matti, et al.
(författare)
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Natal dispersal does not entail survival costs but is linked to breeding dispersal in a migratory shorebird, the southern dunlin Calidris alpina schinzii
- 2022
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; :8
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Tidskriftsartikel (refereegranskat)abstract
- The costs and benefits of dispersal are often assessed by comparing fitness between dispersing and non-dispersing individuals. Importantly, individuals that disperse between their natal and first breeding site may subsequently be more likely to disperse between breeding sites compared to those that remained philopatric to their natal site. Such within-individual consistency in dispersal behaviour can bias local survival estimation, and thus the survival comparison between dispersing and non-dispersing individuals, if breeding dispersal leads to permanent emigration from the study area. We examined whether adult survival correlates with natal dispersal in a migratory shorebird, the southern dunlin Calidris alpina schinzii, in two isolated patchy populations where permanent emigration is expected to be extremely rare. To assess whether local adult survival could be biased by non-random breeding dispersal, we analysed between-patch breeding dispersal probability and quantified within-individual consistency in dispersal. Among females, natal dispersers were more likely to disperse again as adults compared to non-dispersers, while no difference was observed in males which were always highly site faithful. Yet, adult survival did not differ between natal dispersing and non-dispersing individuals in either sex. Breeding dispersal probability was higher in failed compared to successful breeders. Breeding dispersal often resulted in dispersal back to the natal patch, i.e. delayed natal philopatry. Our results suggest no survival costs of dispersal after first reproduction. Despite individual consistency, survival estimates of dispersing individuals were not biased because nearly all available breeding habitat was covered. We show that consistency in dispersal can occur even in site faithful species like the southern dunlin. Studies of the effects of dispersal on survival should therefore account for within-individual consistency in dispersal if not all available breeding habitat is monitored in open populations. In particular, delayed natal philopatry may lead to biased local survival estimates for immigrants when compared with philopatric individuals.
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| 6. |
- Pakanen, Veli-Matti, et al.
(författare)
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Questing abundance of adult taiga ticks Ixodes persulcatus and their Borrelia prevalence at the north-western part of their distribution
- 2020
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Ingår i: Parasites & Vectors. - : Springer Science and Business Media LLC. - 1756-3305. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Because ixodid ticks are vectors of zoonotic pathogens, including Borrelia, information of their abundance, seasonal variation in questing behaviour and pathogen prevalence is important for human health. As ticks are invading new areas northwards, information from these new areas are needed. Taiga tick (Ixodes persulcatus) populations have been recently found at Bothnian Bay, Finland. We assessed seasonal variation in questing abundance of ticks and their pathogen prevalence in coastal deciduous forests near the city of Oulu (latitudes 64-65 degrees) in 2019. Methods We sampled ticks from May until September by cloth dragging 100 meters once a month at eight study sites. We calculated a density index (individuals/100 m(2)) to assess seasonal variation. Samples were screened for Borrelia burgdorferi (sensu lato) (including B. afzelii, B. garinii, B. burgdorferi (sensu stricto) and B. valaisana), Borrelia miyamotoi, Anaplasma phagocytophilum, Rickettsia spp., Neoehrlichia mikurensis, Francisella tularensis and Bartonella spp., Babesia spp. and for the tick-borne encephalitis virus. Results All except one nymph were identified as I. persulcatus. The number of questing adults showed a strong peak in May (median: 6.5 adults/100 m(2)), which is among the highest values reported in northern Europe, and potentially indicates a large population size. After May, the number of questing adults declined steadily with few adults still sampled in August. Nymphs were present from May until September. We found a striking prevalence of Borrelia spp. in adults (62%) and nymphs (40%), with B. garinii (51%) and B. afzelii (63%) being the most common species. In addition, we found that 26% of infected adults were coinfected with at least two Borrelia genospecies, mainly B. garinii and B. afzelii, which are associated with different host species. Conclusions The coastal forest environments at Bothnian Bay seem to provide favourable environments for I. persulcatus and the spread of Borrelia. High tick abundance, a low diversity of the host community and similar host use among larvae and nymphs likely explain the high Borrelia prevalence and coinfection rate. Research on the infestation of the hosts that quantifies the temporal dynamics of immature life stages would reveal important aspects of pathogen circulation in these tick populations.
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| 7. |
- Pakanen, Veli-Matti, et al.
(författare)
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Survival during the pre-fledging period rather than during post-fledging drives variation in local recruitment of an endangered migratory shorebird, the Southern Dunlin Calidris alpina schinzii
- 2021
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 162:1, s. 119-124
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Tidskriftsartikel (refereegranskat)abstract
- The declines in wet-grassland breeding shorebird populations are considered to mainly result from changes in reproduction. While there is plenty of information on nest survival, little reliable information exists on local recruitment due to confounding effects of permanent emigration. Furthermore, few studies have been able to study the roles of pre- and post-fledging survival on local recruitment. Therefore, it is unclear whether local recruitment of young reflects conditions at the breeding sites or at non-breeding sites. We studied an isolated population of the endangered Southern Dunlin (Calidris alpina schinzii) breeding on the west coast of Sweden to examine (1) brood survival (probability of at least one chick fledging) by following broods fates and (2) local recruitment (survival from hatching to 1 year old) using capture-recapture data. We then examined how much of the annual variation in juvenile survival was explained by variation in brood survival. Brood survival was on average 0.58 (annual range 0.08-1.00) and explained 64% of variation in annual local recruitment. Still local recruitment was rather high for a shorebird (0.17, SE = 0.023), which reflects the isolated nature of the study population. Our results suggest that local recruitment seems to be mainly constrained by chick survival during the pre-fledging period. Therefore, management of breeding sites leading to increased brood survival, e.g., reducing predation on chicks, should have strong impacts on local recruitment and local population growth.
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| 8. |
- Pakanen, Veli-Matti, et al.
(författare)
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Survival probability in a small shorebird decreases with the time an individual carries a tracking device
- 2020
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Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 51:10
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Tidskriftsartikel (refereegranskat)abstract
- Effects of tracking devices on survival are generally considered to be small. However, most studies to date have been conducted over a time-period of only one year, neglecting the possible accumulation of negative effects and consequently stronger negative impacts on survival when the individuals have carried the tracking devices for longer periods. We studied the effects of geolocators in a closely monitored and colour-ringed southern dunlin Calidris alpina schinzii population breeding in Finland. Our capture-recapture data spans 2002-2018 and includes individual histories of 338 colour-ringed breeding adult dunlins (the term 'recapture' includes resightings of colour-ringed and individually recognizable birds). These data include 53 adults that were fitted with leg-flag mounted geolocators in 2013-2014. We followed their fates together with other colour-ringed birds not equipped with geolocators until 2018. Geolocators were removed within 1-2 years of attachment or were not removed at all, which allowed us to examine whether carrying a geolocator reduces survival and whether the reduction in survival becomes stronger when geolocators are carried for more than one year. We fit multi-state open population capture-recapture models to the encounter history data. When assessing geolocator effects, we accounted for recapture probabilities, time since marking, and sex and year effects on survival. We found that carrying a geolocator reduced survival, which contrasts with many studies that examined return rates after one year. Importantly, survival declined with the time the individual had carried a geolocator, suggesting that the negative effects accumulate over time. Hence, the longer monitoring of birds carrying a geolocator may explain the difference from previous studies. Despite their larger mass, females tended to be more strongly affected by geolocators than males. Our results warrant caution in conducting tracking studies and suggest that short-term studies examining return rates may not reveal all possible effects of tracking devices on survival.
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| 9. |
- Rönkä, Nelli, et al.
(författare)
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Genetic differentiation in an endangered and strongly philopatric, migrant shorebird
- 2021
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Ingår i: BMC Ecology and Evolution. - : Springer Science and Business Media LLC. - 1472-6785 .- 2730-7182. ; 21:125
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Tidskriftsartikel (refereegranskat)abstract
- Background: Populations living in fragmented habitats may suffer from loss of genetic variation and reduced between-patch dispersal, which are processes that can result in genetic differentiation. This occurs frequently in species with reduced mobility, whereas genetic differentiation is less common among mobile species such as migratory birds. The high dispersal capacity in the latter species usually allows for gene flow even in fragmented landscapes. However, strongly philopatric behaviour can reinforce relative isolation and the degree of genetic differentiation. The Southern Dunlin (Calidris alpina schinzii) is a philopatric, long-distance migratory shorebird and shows reduced dispersal between isolated breeding patches. The endangered population of the Southern Dunlin breeding at the Baltic Sea has suffered from habitat deterioration and fragmentation of coastal meadows. We sampled DNA across the entire population and used 12 polymorphic microsatellite loci to examine whether the environmental changes have resulted in genetic structuring and loss of variation. Results: We found a pattern of isolation-by-distance across the whole Baltic population and genetic differentiation between local populations, even within the southern Baltic. Observed heterozygosity was lower than expected throughout the range and internal relatedness values were positive indicating inbreeding. Conclusions: Our results provide long-term, empirical evidence for the theoretically expected links between habitat fragmentation, population subdivision, and gene flow. They also demonstrate a rare case of genetic differentiation between populations of a long-distance migratory species. The Baltic Southern Dunlin differs from many related shorebird species that show near panmixia, reflecting its philopatric life history and the reduced connectivity of its breeding patches. The results have important implications as they suggest that reduced connectivity of breeding habitats can threaten even long-distance migrants if they show strong philopatry during breeding. The Baltic Southern Dunlin warrants urgent conservation efforts that increase functional connectivity and gene flow between breeding areas.
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| 10. |
- Rönkä, Nelli, et al.
(författare)
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Genetic diversity and dispersal distribution in the endangered Baltic Southern Dunlin Calidris alpina schinzii
- 2014
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Ingår i: International Wader Study Group Annual Conference, Haapsalu, Estonia, 26–29 September 2014. Wader Study Group Bulletin 2015, 121(3); 215..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Genetic analyses provide an indirect way of studying the state and development of populations. Besides obtaining information on the genetic variation per se, with genetics, one can gain knowledge of the behavior of the individuals, e.g. in the context of gene flow. Information on the genetic status and migration rates between subpopulations is important in order to evaluate the need for management and conservation actions aiming to maintain the genetic variation of the population and to ensure its viability. When the population is small, such as in the case of the Baltic Southern Dunlin, the lack of gene flow between local populations may lead to rapid genetic differentiation between them. If dispersal between the subpopulations exists, ensuring good and large enough breeding habitats is important e.g. to attract immigrants and thus help to keep the genetic variation of the populations at a sufficient level. Genetic variation forms the basis for evolutionary change – without it there is nothing natural selection can work on. In this study we examine the genetic variation, population differentiation and dispersal distribution within the Baltic Dunlin population by analyzing 13 microsatellite loci. We have samples from the Finnish Bothnian Bay, SW Finland, Estonia, S Sweden and Denmark. All the data have been collected and the laboratory work done, and the preliminary results already reveal the existence of private alleles, indicating at least some structuring. More than half of the wader species in the world are in decline, including the Baltic Southern Dunlin: classified as critically endangered in all of its breeding countries in the Baltic area, it is one of Europe’s most endangered wader populations. This work is important – besides having concrete implications for the conservation of the Baltic Dunlin, it will also provide basic knowledge which will aid authorities to plan conservation and management actions for endangered species in general.
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| 11. |
- Santangeli, A., et al.
(författare)
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The relative contribution of camera trap technology and citizen science for estimating survival of an endangered African vulture
- 2020
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207. ; 246
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Tidskriftsartikel (refereegranskat)abstract
- Technological advances such as camera traps, and citizen science, coupled with advanced quantitative approaches, can help fill existing knowledge gaps and aid effective conservation. We combine citizen and camera trap observations to estimate survival of the Endangered lappet-faced vulture, assess the relative contribution of data from camera traps and citizens, as well as impact of loss of individual marks (wing tags), on survival estimates. We used data from 762 lappet-faced vultures wing tagged as nestlings during 2006–2017 in western Namibia. Observations of wing tagged individuals were provided by citizens or via camera traps. We formulated a multievent capture-mark-recapture model to estimate survival while accounting for probabilities of resighting by citizens and/or camera traps, recovery of dead individuals, and loss of the wing tag. Survival was relatively high for juveniles (0.79), and increased with age to 0.95. Citizen observations of live and dead birds were low in number. However, when combined with camera trap resightings of live individuals, citizen observations increased the precision of survival estimates of birds older than one year compared to using data from either sources separately. Wing tag loss was high after 5–6 years of tag age. If neglected, tag loss can result in severe underestimation of survival of the older age classes. Overall, we show that filling ecological knowledge gaps is possible through the efficient use of data provided by different sources, and by applying state-of the art approaches that minimise potential biases, such as those due to tag loss. © 2020 The Authors
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| 12. |
- Sormunen, Jani J., et al.
(författare)
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Absence of Francisella tularensis in Finnish Ixodes ricinus and Ixodes persulcatus ticks
- 2021
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Ingår i: Ticks and Tick-borne Diseases. - : Elsevier BV. - 1877-959X .- 1877-9603. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Francisella tularensis subsp. holarctica is the causative agent of tularaemia in Europe. Finland is a high-incidence region for tularaemia, with mosquito bites as the most common sources of infection. However, in Central and Western Europe, ticks (Acari: Ixodidae) have been suggested as the main vectors. Indeed, several studies have reported the pathogen from the locally most common human-biting tick species, Ixodes ricinus. In Finland, the occurrence of the pathogen in ticks has started receiving attention only recently. Here, we collate previous tick screening data from Finland regarding F. tularensis as well as present the results from a novel screening of roughly 15 000 I. ricinus and I. persulcatus collected from across the country. In total, 14 878 ticks collected between 2015 and 2020 were screened for F. tularensis using a TaqMan-based qPCR assay targeting the 23 KDa gene. The combined screening efforts of the current and previous studies, encompassing roughly 20 000 ticks, did not find any positive ticks. Given the negative results despite the considerable sample size, it appears that the pathogen is not circulating in local tick populations in Finland. We discuss some possible reasons for the lack of the bacterium in ticks in this high-incidence region of tularaemia.
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| 13. |
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| 14. |
- Tolvanen, Jere, et al.
(författare)
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Quantitative genetics of the use of conspecific and heterospecific social cues for breeding site choice
- 2020
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Ingår i: Evolution. - : WILEY. - 0014-3820 .- 1558-5646. ; 74:10, s. 2332-2347
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Tidskriftsartikel (refereegranskat)abstract
- Social information use for decision-making is common and affects ecological and evolutionary processes, including social aggregation, species coexistence, and cultural evolution. Despite increasing ecological knowledge on social information use, very little is known about its genetic basis and therefore its evolutionary potential. Genetic variation in a trait affecting an individual's social and nonsocial environment may have important implications for population dynamics, interspecific interactions, and, for expression of other, environmentally plastic traits. We estimated repeatability, additive genetic variance, and heritability of the use of conspecific and heterospecific social cues (abundance and breeding success) for breeding site choice in a population of wild collared flycatchersFicedula albicollis. Repeatability was found for two social cues: previous year conspecific breeding success and previous year heterospecific abundance. Yet, additive genetic variances for these two social cues, and thus heritabilities, were low. This suggests that most of the phenotypic variation in the use of social cues and resulting conspecific and heterospecific social environment experienced by individuals in this population stems from phenotypic plasticity. Given the important role of social information use on ecological and evolutionary processes, more studies on genetic versus environmental determinism of social information use are needed.
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