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1.	Balbontin, Javier, et al. (författare) Age-related change in breeding performance in early life is associated with an increase in competence in the migratory barn swallow Hirundo rustica 2007 Ingår i: Journal of Animal Ecology. - : Wiley. - 1365-2656 .- 0021-8790. ; 76:5, s. 915-925 Tidskriftsartikel (refereegranskat)abstract 1. We investigated age-related changes in two reproductive traits (laying date and annual fecundity) in barn swallows Hirundo rustica L. using a mixed model approach to di-stinguish among between- and within-individual changes in breeding performance with age. 2. We tested predictions of age-related improvements of competence (i.e. constraint hypothesis) and age-related progressive disappearance of poor-quality breeders (i.e. selection hypothesis) to explain age-related increase in breeding performance in early life. 3. Reproductive success increased in early life, reaching a plateau at middle age (e.g. at 3 years of age) and decreasing at older age (> 4 years). Age-related changes in breeding success were due mainly to an effect of female age. 4. Age of both female and male affected timing of reproduction. Final linear mixed effect models (LME) for laying date included main and quadratic terms for female and male age, suggesting a deterioration in reproductive performance at older age for both males and females. 5. We found evidence supporting the constraints hypothesis that increases in competence within individuals, with ageing being the most probable cause of the observed increase in breeding performance with age in early life. Two mechanisms were implicated: (1) advance in male arrival date with age provided middle-aged males with better access to mates. Yearling males arrived later to the breeding grounds and therefore had limited access to high-quality mates. (2) Breeding pairs maintaining bonds for 2 consecutive years (experienced pairs) had higher fecundity than newly formed inexperienced breeding pairs. 6. There was no support for the selection hypothesis because breeding performance was not correlated with life span. 7. We found a within-individual deterioration in breeding and migratory performance (arrival date) in the oldest age-classes consistent with senescence in these reproductive and migratory traits.
2.	Bensch, Staffan, et al. (författare) The use of molecular methods in studies of avian haemosporidians 2020 Ingår i: Avian Malaria and Related Parasites in the Tropics : Ecology, Evolution and Systematics - Ecology, Evolution and Systematics. - Cham : Springer International Publishing. - 9783030516321 - 9783030516338 ; , s. 113-135 Bokkapitel (refereegranskat)abstract During the last two decades, molecular methods to study mitochondrial DNA sequence variation have become an important part in the studies of avian haemosporidians. Up until recently, these methods have primarily been used for identification of the parasites and for tentative phylogenetic reconstructions, allowing researchers not trained in traditional parasitology to compare data across the globe. However, with the introduction of genome and transcriptome sequencing, studies are emerging that go deeper into the genetics and molecular biology of the parasites. In this chapter, we describe and summarize the common methods used for genetic barcoding of the parasites and give an introduction of what to take into account when designing a molecular study of avian haemosporidians. This chapter further discusses why nuclear genetic data are needed in order to answer several important ecological and evolutionary questions and which methods to use in order to overcome the obstacles of obtaining nuclear data of the parasites. Finally, this chapter highlights the challenges and opportunities that come with the use of molecular methods, such as how to study and interpret prevalence, the challenge of aborted developments, and how to obtain data for more robust phylogenies and population structure studies of the parasites.
3.	Ferraguti, Martina, et al. (författare) Environmental, geographical and time-related impacts on avian malaria infections in native and introduced populations of house sparrows (Passer domesticus), a globally invasive species 2023 Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 32:5, s. 809-823 Tidskriftsartikel (refereegranskat)abstract Aim: The increasing spread of vector-borne diseases has resulted in severe health concerns for humans, domestic animals and wildlife, with changes in land use and the introduction of invasive species being among the main possible causes for this increase. We explored several ecological drivers potentially affecting the local prevalence and richness of avian malaria parasite lineages in native and introduced house sparrows (Passer domesticus) populations. Location: Global. Time period: 2002–2019. Major taxa studied: Avian Plasmodium parasites in house sparrows. Methods: We analysed data from 2,220 samples from 69 localities across all continents, except Antarctica. The influence of environment (urbanization index and human density), geography (altitude, latitude, hemisphere) and time (bird breeding season and years since introduction) were analysed using generalized additive mixed models (GAMMs) and random forests. Results: Overall, 670 sparrows (30.2%) were infected with 22 Plasmodium lineages. In native populations, parasite prevalence was positively related to urbanization index, with the highest prevalence values in areas with intermediate urbanization levels. Likewise, in introduced populations, prevalence was positively associated with urbanization index; however, higher infection occurred in areas with either extreme high or low levels of urbanization. In introduced populations, the number of parasite lineages increased with altitude and with the years elapsed since the establishment of sparrows in a new locality. Here, after a decline in the number of parasite lineages in the first 30 years, an increase from 40 years onwards was detected. Main conclusions: Urbanization was related to parasite prevalence in both native and introduced bird populations. In invaded areas, altitude and time since bird introduction were related to the number of Plasmodium lineages found to be infecting sparrows.
4.	Ferraguti, Martina, et al. (författare) From Africa to Europe : evidence of transmission of a tropical Plasmodium lineage in Spanish populations of house sparrows 2019 Ingår i: Parasites & Vectors. - : Springer Science and Business Media LLC. - 1756-3305. ; 12:1 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: Avian malaria parasites are a highly diverse group that commonly infect birds and have deleterious effects on their hosts. Some parasite lineages are geographically widespread and infect many host species in many regions. Bird migration, natural dispersal, invasive species and human-mediated introductions into areas where competent insect vectors are present, are probably the main drivers of the current distribution of avian malaria parasites. METHODS: A total of 412 and 2588 wild house sparrows (Passer domesticus) were captured in 2012 and 2013 in two areas of the Iberian Peninsula (central and southern Spain, respectively). Genomic DNA was extracted from blood samples; parasite lineages were sequenced and identified by comparing with GenBank and/or MalAvi databases. RESULTS: Thirteen Plasmodium lineages were identified in house sparrows corresponding to three major clades. Five individuals were infected by the African Plasmodium lineage PAGRI02, which has been proposed to actively circulate only in Africa. CONCLUSIONS: Despite the low prevalence of PAGRI02 in sparrows in Spain, our results suggest that the area of transmission of this parasite is more widespread than previously thought and covers both Africa and Europe. Further studies of the global distribution of Plasmodium lineages infecting wild birds are required to identify the current transmission areas of these parasites. This is vital given the current scenario of global change that is providing new opportunities for avian malaria transmission into areas where parasites were previously absent.
5.	Garcia-Longoria, Luz, et al. (författare) Detecting transmission areas of malaria parasites in a migratory bird species. 2015 Ingår i: Parasitology. - 1469-8161. ; 142:9, s. 1215-1220 Tidskriftsartikel (refereegranskat)abstract The identification of the regions where vector-borne diseases are transmitted is essential to study transmission patterns and to recognize future changes in environmental conditions that may potentially influence the transmission areas. SGS1, one of the lineages of Plasmodium relictum, is known to have active transmission in tropical Africa and temperate regions of Europe. Nuclear sequence data from isolates infected with SGS1 (based on merozoite surface protein 1 (MSP1) allelic diversity) have provided new insights on the distribution and transmission areas of these allelic variants. For example, MSP1 alleles transmitted in Africa differ from those transmitted in Europe, suggesting the existence of two populations of SGS1 lineages. However, no study has analysed the distribution of African and European transmitted alleles in Afro-Palearctic migratory birds. With this aim, we used a highly variable molecular marker to investigate whether juvenile house martins become infected in Europe before their first migration to Africa. We explored the MSP1 allelic diversity of P. relictum in adult and juvenile house martins. We found that juveniles were infected with SGS1 during their first weeks of life, confirming active transmission of SGS1 to house martins in Europe. Moreover, we found that all the juveniles and most of adults were infected with one European transmitted MSP1 allele, whereas two adult birds were infected with two African transmitted MSP1 alleles. These findings suggest that house martins are exposed to different strains of P. relictum in their winter and breeding quarters.
6.	Garcia-Longoria, Luz, et al. (författare) Diversity and host assemblage of avian haemosporidians in different terrestrial ecoregions of Peru 2022 Ingår i: Current Zoology. - : Oxford University Press (OUP). - 1674-5507 .- 2396-9814. ; 68:1, s. 27-40 Tidskriftsartikel (refereegranskat)abstract Characterizing the diversity and structure of host-parasite communities is crucial to understanding their eco-evolutionary dynamics. Malaria and related haemosporidian parasites are responsible for fitness loss and mortality in bird species worldwide. However, despite exhibiting the greatest ornithological biodiversity, avian haemosporidians from Neotropical regions are quite unexplored. Here, we analyze the genetic diversity of bird haemosporidian parasites (Plasmodium and Haemoproteus) in 1,336 individuals belonging to 206 bird species to explore for differences in diversity of parasite lineages and bird species across 5 well-differentiated Peruvian ecoregions. We detected 70 different haemosporidian lineages infecting 74 bird species. We showed that 25 out of the 70 haplotypes had not been previously recorded. Moreover, we also identified 81 new host-parasite interactions representing new host records for these haemosporidian parasites. Our outcomes revealed that the effective diversity (as well as the richness, abundance, and Shannon-Weaver index) for both birds and parasite lineages was higher in Amazon basin ecoregions. Furthermore, we also showed that ecoregions with greater diversity of bird species also had high parasite richness, hence suggesting that host community is crucial in explaining parasite richness. Generalist parasites were found in ecoregions with lower bird diversity, implying that the abundance and richness of hosts may shape the exploitation strategy followed by haemosporidian parasites. These outcomes reveal that Neotropical region is a major reservoir of unidentified haemosporidian lineages. Further studies analyzing host distribution and specificity of these parasites in the tropics will provide important knowledge about phylogenetic relationships, phylogeography, and patterns of evolution and distribution of haemosporidian parasites.
7.	Garcia-Longoria, Luz, et al. (författare) Host-parasite interaction explains variation in the prevalence of avian haemosporidians at the community level 2019 Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:3 Tidskriftsartikel (refereegranskat)abstract Parasites are a selective force that shape host community structure and dynamics, but host communities can also influence parasitism. Understanding the dual nature from host-parasite interactions can be facilitated by quantifying the variation in parasite prevalence among host species and then comparing that variation to other ecological factors that are known to also shape host communities. Avian haemosporidian parasites (e.g. Plasmodium and Haemoproteus) are abundant and widespread representing an excellent model for the study of host-parasite interactions. Several geographic and environmental factors have been suggested to determine prevalence of avian haemosporidians in bird communities. However, it remains unknown whether host and parasite traits, represented by phylogenetic distances among species and degree of specialization in host-parasite relationships, can influence infection status. The aims of this study were to analyze factors affecting infection status in a bird community and to test whether the degree of parasite specialization on their hosts is determined by host traits. Our statistical analyses suggest that infection status is mainly determined by the interaction between host species and parasite lineages where tolerance and/or susceptibility to parasites plays an essential role. Additionally, we found that although some of the parasite lineages infected a low number of bird individuals, the species they infected were distantly related and therefore the parasites themselves should not be considered typical host specialists. Infection status was higher for generalist than for specialist parasites in some, but not all, host species. These results suggest that detected prevalence in a species mainly results from the interaction between host immune defences and parasite exploitation strategies wherein the result of an association between particular parasite lineages and particular host species is idiosyncratic.
8.	Garcia-Longoria, Luz, et al. (författare) Reciprocal positive effects on parasitemia between coinfecting haemosporidian parasites in house sparrows 2022 Ingår i: BMC Ecology and Evolution. - : Springer Science and Business Media LLC. - 2730-7182. ; 22:1 Tidskriftsartikel (refereegranskat)abstract Background: Hosts are often simultaneously infected with several parasite species. These co-infections can lead to within-host interactions of parasites, including mutualism and competition, which may affect both virulence and transmission. Birds are frequently co-infected with different haemosporidian parasites, but very little is known about if and how these parasites interact in natural host populations and what consequences there are for the infected hosts. We therefore set out to study Plasmodium and Haemoproteus parasites in house sparrows Passer domesticus with naturally acquired infections using a protocol where the parasitemia (infection intensity) is quantified by qPCR separately for the two parasites. We analysed infection status (presence/absence of the parasite) and parasitemia of parasites in the blood of both adult and juvenile house sparrows repeatedly over the season. Results: Haemoproteus passeris and Plasmodium relictum were the two dominating parasite species, found in 99% of the analyzed Sanger sequences. All birds were infected with both Plasmodium and Haemoproteus parasites during the study period. Seasonality explained infection status for both parasites in the adults: H. passeris was completely absent in the winter while P. relictum was present all year round. Among adults infected with H. passeris there was a positive effect of P. relictum parasitemia on H. passeris parasitemia and likewise among adults infected with P. relictum there was a positive effect of H. passeris parasitemia on P. relictum parasitemia. No such associations on parasitemia were seen in juvenile house sparrows. Conclusions: The reciprocal positive relationships in parasitemia between P. relictum and H. passeris in adult house sparrows suggests either mutualistic interactions between these frequently occurring parasites or that there is variation in immune responses among house sparrow individuals, hence some individuals suppress the parasitemia of both parasites whereas other individuals suppress neither. Our detailed screening of haemosporidian parasites over the season shows that co-infections are very frequent in both juvenile and adult house sparrows, and since co-infections often have stronger negative effects on host fitness than the single infection, it is imperative to use screening systems with the ability to detect multiple parasites in ecological studies of host-parasite interactions.
9.	Hellgren, Olof, et al. (författare) Global phylogeography of the avian malaria pathogen Plasmodium relictum based on MSP1 allelic diversity 2015 Ingår i: Ecography. - : Wiley. - 1600-0587 .- 0906-7590. ; 38:8, s. 842-850 Tidskriftsartikel (refereegranskat)abstract Knowing the genetic variation that occurs in pathogen populations and how it is distributed across geographical areas is essential to understand parasite epidemiology, local patterns of virulence, and evolution of host-resistance. In addition, it is important to identify populations of pathogens that are evolutionarily independent and thus free' to adapt to hosts and environments. Here, we investigated genetic variation in the globally distributed, highly invasive avian malaria parasite Plasmodium relictum, which has several distinctive mitochondrial haplotyps (cyt b lineages, SGS1, GRW11 and GRW4). The phylogeography of P. relictum was accessed using the highly variable nuclear gene merozoite surface protein 1 (MSP1), a gene linked to the invasion biology of the parasite. We show that the lineage GRW4 is evolutionarily independent of GRW11 and SGS1 whereas GRW11 and SGS1 share MSP1 alleles and thus suggesting the presence of two distinct species (GRW4 versus SGS1 and GRW11). Further, there were significant differences in the global distribution of MSP1 alleles with differences between GRW4 alleles in the New and the Old World. For SGS1, a lineage formerly believed to have both tropical and temperate transmission, there were clear differences in MSP1 alleles transmitted in tropical Africa compared to the temperate regions of Europe and Asia. Further, we highlight the occurrence of multiple MSP1 alleles in GRW4 isolates from the Hawaiian Islands, where the parasite has contributed to declines and extinctions of endemic forest birds since it was introduced. This study stresses the importance of multiple independent loci for understanding patterns of transmission and evolutionary independence across avian malaria parasites.
10.	Hermansen, Jo S., et al. (författare) Hybrid speciation through sorting of parental incompatibilities in Italian sparrows 2014 Ingår i: Molecular Ecology. - : Wiley. - 0962-1083. ; 23, s. 5831-5842 Tidskriftsartikel (refereegranskat)abstract Speciation by hybridization is emerging as a significant contributor to biological diversification. Yet, little is known about the relative contributions of (i) evolutionary novelty and (ii) sorting of pre-existing parental incompatibilities to the build-up of reproductive isolation under this mode of speciation. Few studies have addressed empirically whether hybrid animal taxa are intrinsically isolated from their parents, and no study has so far investigated by which of the two aforementioned routes intrinsic barriers evolve. Here, we show that sorting of pre-existing parental incompatibilities contributes to intrinsic isolation of a hybrid animal taxon. Using a genomic cline framework, we demonstrate that the sex-linked and mitonuclear incompatibilities isolating the homoploid hybrid Italian sparrow at its two geographically separated hybrid–parent boundaries represent a subset of those contributing to reproductive isolation between its parent species, house and Spanish sparrows. Should such a sorting mechanism prove to be pervasive, the circumstances promoting homoploid hybrid speciation may be broader than currently thought, and indeed, there may be many cryptic hybrid taxa separated from their parent species by sorted, inherited incompatibilities.
11.	Hermosell, Ignacio G., et al. (författare) Sex determination in barn swallows Hirundo rustica by means of discriminant analysis in two European populations 2007 Ingår i: Ardeola. - 0570-7358. ; 54:1, s. 93-100 Tidskriftsartikel (refereegranskat)abstract Aims: Differences in morphology in adult barn swallows were investigated using bone and feather measurements taken from birds from a northern (Danish) and a southern (Spanish) European population. Discriminant Function Analysis was used to help in discriminating the sex of individuals of both populations. Location: Badajoz (Spain) and Kraghede (Denmark). Methods: Two discriminant functions were obtained using biometric data from adult individuals, one for each European population. These functions were validated using external data from a sample of an Italian and Ukrainian barn swallow populations. Results: Three morphometric variables: the length of the outermost tail feathers, the length of the inner tail feathers and the length of the keel were retained in the discriminant function in the two populations studied. Overall, these functions allowed us to determine the sex of adult birds with 90.1 % and 91.9 % accuracy for the Spanish and the Danish populations, respectively External validation using a sample from the Italian population to validate Spanish discriminant function and from the Ukrainian population to validate the Danish discriminant function showed that 91 % of Italian and 86 % of Ukrainian swallows were correctly classified. Conclusions: The two discriminant functions obtained would be highly valuable in future work carried out on this species because it would allow researchers to determine the sex of individuals shortly after arrival to the breeding areas without having to wait for the beginning of courtship or incubation for reliable sexing.
12.	Marzal, Alfonso, et al. (författare) Co-infections by malaria parasites decrease feather growth but not feather quality in house martin 2013 Ingår i: Journal of Avian Biology. - 0908-8857. ; 44:5, s. 437-444 Tidskriftsartikel (refereegranskat)abstract During moult, stressors such as malaria and related haemosporidian parasites (e.g. Plasmodium and Haemoproteus) could affect the growth rate and quality of feathers, which in turn may compromise future reproduction and survival. Recent advances in molecular methods to study parasites have revealed that co-infections with multiple parasites are frequent in bird-malaria parasite systems. However, there is no study of the consequences of co-infections on the moult of birds. In house martins Delichon urbica captured and studied at a breeding site in Europe during 11 yr, we measured the quality and the growth rate of tail feathers moulted in the African winter quarters in parallel with the infection status of blood parasites that are also transmitted on the wintering ground. Here we tested if the infection with two haemosporidian parasite lineages has more negative effects than a single lineage infection. We found that birds with haemosporidian infection had lower body condition. We also found that birds co-infected with two haemosporidian lineages had the lowest inferred growth rate of their tail feathers as compared with uninfected and single infected individuals, but co-infections had no effect on feather quality. In addition, feather quality was negatively correlated with feather growth rate, suggesting that these two traits are traded-off against each other. We encourage the study of haemosporidian parasite infection as potential mechanism driving this trade-off in wild populations of birds.
13.	Marzal, Alfonso, et al. (författare) Diversity, Loss, and Gain of Malaria Parasites in a Globally Invasive Bird. 2011 Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:7 Tidskriftsartikel (refereegranskat)abstract Invasive species can displace natives, and thus identifying the traits that make aliens successful is crucial for predicting and preventing biodiversity loss. Pathogens may play an important role in the invasive process, facilitating colonization of their hosts in new continents and islands. According to the Novel Weapon Hypothesis, colonizers may out-compete local native species by bringing with them novel pathogens to which native species are not adapted. In contrast, the Enemy Release Hypothesis suggests that flourishing colonizers are successful because they have left their pathogens behind. To assess the role of avian malaria and related haemosporidian parasites in the global spread of a common invasive bird, we examined the prevalence and genetic diversity of haemosporidian parasites (order Haemosporida, genera Plasmodium and Haemoproteus) infecting house sparrows (Passer domesticus). We sampled house sparrows (N = 1820) from 58 locations on 6 continents. All the samples were tested using PCR-based methods; blood films from the PCR-positive birds were examined microscopically to identify parasite species. The results show that haemosporidian parasites in the house sparrows' native range are replaced by species from local host-generalist parasite fauna in the alien environments of North and South America. Furthermore, sparrows in colonized regions displayed a lower diversity and prevalence of parasite infections. Because the house sparrow lost its native parasites when colonizing the American continents, the release from these natural enemies may have facilitated its invasion in the last two centuries. Our findings therefore reject the Novel Weapon Hypothesis and are concordant with the Enemy Release Hypothesis.
14.	Marzal, Alfonso, et al. (författare) Fitness costs of an immune response in the house martin (Delichon urbica) 2007 Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 1432-0762 .- 0340-5443. ; 61:10, s. 1573-1580 Tidskriftsartikel (refereegranskat)abstract Immune responses constitute a major way for hosts to defend themselves against parasites. Because hosts do not habitually produce strong responses all the time, immune responses might be costly to produce or maintain. We tested experimentally if the production of a response to a challenge with a novel antigen resulted in a cost in terms of fitness using the highly colonial house martin Delichon urbica as a model system. We injected adult breeding birds during laying of the first clutch with either Newcastle disease virus (NDV) or a control injection, and the clutch was subsequently removed to induce relaying. NDV stimulates the non-specific immune system, causing production of antibodies during a period of more than 2 weeks. Accordingly, we found an increase in leukocyte counts in experimental birds compared to controls. Experimental treatment reduced the frequency of re-laying, caused a delay in timing of relaying and a reduction in brood size. Quality of nestlings in terms of body size, body mass and T-cell-mediated immune response did not differ significantly between treatments. Overall, seasonal reproductive success differed significantly between treatments, showing that the production of an immune response by adult birds is costly in terms of future fecundity.
15.	Marzal, Alfonso, et al. (författare) Malaria infection and feather growth rate predict reproductive success in house martins 2013 Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 171:4, s. 853-861 Tidskriftsartikel (refereegranskat)abstract Carry-over effects take place when events occurring in one season influence individual performance in a subsequent season. Blood parasites (e.g. Plasmodium and Haemoproteus) have strong negative effects on the body condition of their hosts and could slow the rate of feather growth on the wintering grounds. In turn, these winter moult costs could reduce reproductive success in the following breeding season. In house martins Delichon urbica captured and studied at a breeding site in Europe, we used ptilochronology to measure growth rate of tail feathers moulted on the winter range in Africa, and assessed infection status of blood parasites transmitted on the wintering grounds. We found a negative association between haemosporidian parasite infection status and inferred growth rate of tail feathers. A low feather growth rate and blood parasite infections were related to a delay in laying date in their European breeding quarters. In addition, clutch size and the number of fledglings were negatively related to a delayed laying date and blood parasite infection. These results stress the importance of blood parasites and feather growth rate as potentially mechanisms driving carry-over effects to explain fitness differences in wild populations of migratory birds.
16.	Muriel, Jaime, et al. (författare) Prevalence and diversity of avian haemosporidians may vary with anthropogenic disturbance in tropical habitats in myanmar 2021 Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 13:3 Tidskriftsartikel (refereegranskat)abstract Avian malaria and related haemosporidians (genera Haemoproteus, Plasmodium and Leu-cocytozoon) infect most clades of bird. Although these parasites are present in almost all continents, they have been irregularly studied across different geographical regions. Despite the high bird diversity in Asia, the diversity of avian haemosporidians in this region is largely unknown. Moreover, anthropogenic changes to habitats in tropical regions may have a profound impact on the overall composition of haemosporidian communities. Here we analyzed the diversity and host association of bird haemosporidians from areas with different degrees of anthropogenic disturbance in Myan-mar, revealing an unexplored diversity of these parasites (27% of newly-discovered haemosporid-ian lineages, and 64% of new records of host–parasite assemblages) in these tropical environments. This newly discovered diversity will be valuable for detecting host range and transmission areas of haemosporidian parasites. We also found slightly higher haemosporidian prevalence and diversity in birds from paddy fields than in individuals from urban areas and hills, thus implying that human alteration of natural environments may affect the dynamics of vector-borne diseases. These outcomes provide valuable insights for biodiversity conservation management in threatened tropical ecosystems.
17.	Neto, Júlio Manuel, et al. (författare) Seasonal dynamics of haemosporidian (Apicomplexa, Haemosporida) parasites in house sparrows Passer domesticus at four European sites : comparison between lineages and the importance of screening methods 2020 Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519. ; 50:6-7, s. 523-532 Tidskriftsartikel (refereegranskat)abstract Infectious diseases often vary seasonally in a predictable manner, and seasonality may be responsible for geographical differences in prevalence. In temperate regions, vector-borne parasites such as malaria are expected to evolve lower virulence and a time-varying strategy to invest more in transmission when vectors are available. A previous model of seasonal variation of avian malaria described a double peak in prevalence of Plasmodium parasites in multiple hosts resulting from spring relapses and transmission to susceptible individuals in summer. However, this model was rejected by a study describing different patterns of seasonal variation of two Plasmodium spp. at the same site, with the double peak only apparent when these species were combined. Here, we assessed the seasonal variation in prevalence of haemosporidian parasites (Plasmodium, Haemoproteus and Leucocytozoon) in house sparrows (Passer domesticus) sampled across 1 year at four temperate European sites spanning a latitudinal range of 17°. We showed that parasite prevalence and diversity decreased with increasing latitude, but the parasite communities differed between sites, with only one Plasmodium lineage (P_SGS1) occurring at all sites. Moreover, the nested PCR method commonly used to detect and identify haemosporidian parasites strongly underestimated co-infections of Haemoproteus and Plasmodium, significantly biasing the pattern of seasonal variation, so additional molecular methods were used. Finally, we showed that: (i) seasonal variation in prevalence of haemosporidian parasites varied between study sites and parasite lineages/species/genera, describing further cases where the double peak model is not met; (ii) the seasonal dynamics of single lineages (P_SGS1) varied between sites; and (iii) unexpectedly, seasonality was greatest at the southernmost site, a pattern that was mostly driven by lineage H_PADOM05. Limitations of the genotyping methods and consequences of pooling (parasite lineages, sites and years) in studies of haemosporidian parasites are discussed and recommendations proposed, since these actions may obscure the patterns of prevalence and limit ecological inferences.
18.	Papoli Yazdi, Homa, et al. (författare) Extensive transgressive gene expression in testis but not ovary in the homoploid hybrid Italian sparrow 2022 Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 31:15, s. 4067-4077 Tidskriftsartikel (refereegranskat)abstract Hybridization can result in novel allelic combinations which can impact the hybrid phenotype through changes in gene expression. While misexpression in F1 hybrids is well documented, how gene expression evolves in stabilized hybrid taxa remains an open question. As gene expression evolves in a stabilizing manner, break-up of co-evolved cis- and trans-regulatory elements could lead to transgressive patterns of gene expression in hybrids. Here, we address to what extent gonad gene expression has evolved in an established and stable homoploid hybrid, the Italian sparrow (Passer italiae). Through comparison of gene expression in gonads from individuals of the two parental species (i.e., house and Spanish sparrow) to that of Italian sparrows, we find evidence for strongly transgressive expression in male Italian sparrows—2530 genes (22% of testis genes tested for inheritance) exhibit expression patterns outside the range of both parent species. In contrast, Italian sparrow ovary expression was similar to that of one of the parent species, the house sparrow (Passer domesticus). Moreover, the Italian sparrow testis transcriptome is 26 times as diverged from those of the parent species as the parental transcriptomes are from each other, despite being genetically intermediate. This highlights the potential for regulation of gene expression to produce novel variation following hybridization. Genes involved in mitochondrial respiratory chain complexes and protein synthesis are enriched in the subset that is over-dominantly expressed in Italian sparrow testis, suggesting that selection on key functions has moulded the hybrid Italian sparrow transcriptome.
19.	Teplitsky, Celine, et al. (författare) Assessing Multivariate Constraints to Evolution across Ten Long-Term Avian Studies 2014 Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:3, s. e90444- Tidskriftsartikel (refereegranskat)abstract Background: In a rapidly changing world, it is of fundamental importance to understand processes constraining or facilitating adaptation through microevolution. As different traits of an organism covary, genetic correlations are expected to affect evolutionary trajectories. However, only limited empirical data are available. Methodology/Principal Findings: We investigate the extent to which multivariate constraints affect the rate of adaptation, focusing on four morphological traits often shown to harbour large amounts of genetic variance and considered to be subject to limited evolutionary constraints. Our data set includes unique long-term data for seven bird species and a total of 10 populations. We estimate population-specific matrices of genetic correlations and multivariate selection coefficients to predict evolutionary responses to selection. Using Bayesian methods that facilitate the propagation of errors in estimates, we compare (1) the rate of adaptation based on predicted response to selection when including genetic correlations with predictions from models where these genetic correlations were set to zero and (2) the multivariate evolvability in the direction of current selection to the average evolvability in random directions of the phenotypic space. We show that genetic correlations on average decrease the predicted rate of adaptation by 28%. Multivariate evolvability in the direction of current selection was systematically lower than average evolvability in random directions of space. These significant reductions in the rate of adaptation and reduced evolvability were due to a general nonalignment of selection and genetic variance, notably orthogonality of directional selection with the size axis along which most (60%) of the genetic variance is found. Conclusions: These results suggest that genetic correlations can impose significant constraints on the evolution of avian morphology in wild populations. This could have important impacts on evolutionary dynamics and hence population persistence in the face of rapid environmental change.
20.	Videvall, Elin, et al. (författare) The uropygial gland microbiome of house sparrows with malaria infection 2021 Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 52:2 Tidskriftsartikel (refereegranskat)abstract Birds secrete preen oil from the uropygial (preen) gland which is used to maintain feather integrity and communicate through odour. The uropygial secretion is believed to influence host attractiveness to biting insects, thereby altering the risk of infection by vector-transmitted blood parasites. Previous studies have documented a presence of bacteria in the uropygial secretion; however, the microbial community in the gland is still largely unknown. In addition, we have no information yet as to whether there are any associations between these uropygial gland microbes and haemosporidian parasite infection. Here, we characterise the microbiome of the uropygial gland secretion in 23 wild-caught house sparrows Passer domesticus from Peru and investigate whether individuals with natural malaria Plasmodium infection have different preen oil microbiota than uninfected birds. We found no differences in microbial alpha diversity or richness, and malaria infection explained approximately 5% of the overall microbiome composition, however, this was not statistically significant. On the other hand, birds with malaria infection had significantly higher abundances of bacteria from the genera Arthrobacter and Micrococcus in their gland, whereas uninfected birds harboured higher abundances of Rhodococcus, Phenylobacterium and Enhydrobacter. These first results of the uropygial gland microbiome in malaria-infected birds illustrate the presence of a more specific relationship between certain members of the gland microbiota and Plasmodium parasites in birds, which opens up new questions on the role of the uropygial gland in avian health.

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