| 1. |
- Arct, Aneta, et al.
(author)
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Benefits of extra-pair mating may depend on environmental conditions-an experimental study in the blue tit (Cyanistes caeruleus)
- 2013
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In: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 67:11, s. 1809-1815
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Journal article (peer-reviewed)abstract
- Extra-pair mating constitutes a relatively common reproductive strategy in many socially monogamous bird species. This strategy may considerably improve reproductive success of males, but female benefits from extra-pair matings still remain unclear and empirical evidence is scarce. This may be because genetic benefits of extra-pair mating are not always revealed. It is possible that they are shown only in unfavourable environmental conditions and hence problems arise with detecting differences between within- and extra-pair offspring whose performance is measured under favourable conditions. In order to test this prediction, we manipulated environmental conditions by altering brood sizes of blue tits and compared phenotypic characteristics of within- and extra-pair offspring in mixed-paternity broods. We found that extra-pair young exhibited a higher response to phytohemagglutinin in comparison to within-pair young, but this was only observed among nestlings from experimentally enlarged broods. These results indicate that genetic benefits may interact with the environment, and thus benefits of extra-pair mating are likely to become visible only when conditions are relatively unfavourable.
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| 2. |
- Dubiec, Anna, et al.
(author)
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Differential prevalence and diversity of haemosporidian parasites in two sympatric closely related nonmigratory passerines
- 2016
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In: Parasitology. - 0031-1820 .- 1469-8161. ; 143:10, s. 1320-1329
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Journal article (peer-reviewed)abstract
- Haemosporidian parasites infecting birds show distinct heterogeneity in their distribution among host species. However, despite numerous studies on the prevalence and diversity of parasite communities across species, very little is known on patterns of differences between them. Such data is lacking because up to date the majority of studies explored the patterns of variation in infections in different years, different time of sampling within a year or a breeding cycle, different study sites or was based on a small sample size, all of which may affect the estimates of prevalence and parasite diversity. Here, the prevalence, richness and diversity of haemosporidian parasites from the genera Plasmodium and Haemoproteus were studied in two closely related non-migratory hole-nesting passerines: Great Tits and Blue Tits. Birds were sampled in sympatrically breeding populations during two seasons at the same stage of their breeding cycle - late nestling care. Great Tits were more prevalently infected with Plasmodium and Haemoproteus parasites (97.1 vs 71.2%), harboured a higher proportion of multiple infections (26.2 vs 3.2%) and had a more diverse parasite community (11 vs 5 parasite lineages) than Blue Tits. Observed differences between two host species are discussed with reference to their breeding densities and immunological and behavioural characteristics.
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| 3. |
- Dubiec, Anna, et al.
(author)
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Intra-individual changes in haemosporidian infections over the nesting period in great tit females
- 2017
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In: Parasitology Research. - : Springer. - 0932-0113 .- 1432-1955. ; 116:9, s. 2385-2392
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Journal article (peer-reviewed)abstract
- Prevalence of haemosporidian parasites in bird populations varies temporally both between years and within a year. In contrast to variation at the population level, relatively little is known about variation in infection attributes at the individual level, especially in non-migratory species. We examined intra-individual changes in the presence and identity of haemosporidian parasites (genera Plasmodium and Haemoproteus) over the course of the nesting period in females of great tits (Parus major)-a species considered to be resident over much of its distribution range. Birds were sampled during two stages of the nesting period: nest building and nestling rearing. The mean time interval between sampling occasions was 43 days. Between the first and second samplings, 30.6% of females gained at least one parasite lineage and 18.5% lost the lineage. Haemoproteus gains were over three times more common than Plasmodium gains. The probability of the lineage gain decreased with the date of the first sampling, was higher in individuals in better body condition and differed between years, but was not associated with the host age. The probability of the lineage loss was not explained by any of the considered parameters except for year. These results indicate that in a large proportion of a population, infection attributes (presence/absence and/or parasite identity) may change over the nesting period and the occurrence of such changes may be associated with the individual quality. Consequently, this phenomenon should be taken into account to correctly interpret parasite-mediated effects.
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| 4. |
- Janas, Katarzyna, et al.
(author)
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Influence of haemosporidian infection status on structural and carotenoid-based colouration in the blue tit Cyanistes caeruleus
- 2018
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In: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 49:10
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Journal article (peer-reviewed)abstract
- Hypotheses postulating parasite-mediated mate choice intrinsically assume that parasitic infections deteriorate the quality of male ornamentation. Although this assumption has often been studied in the context of carotenoid-based colouration, only few studies investigated this with reference to structural feather colouration, which in many species plays a vital role in sexual selection. Here, using a three-years dataset from a wild blue tit Cyanistes caeruleus population, we examined the relationship between the haemosporidian infection status and the structural as well as the carotenoid-based colouration of adult birds. Furthermore, we investigated potential differences in the impact on feather colouration between two examined parasite genera: Plasmodium and Haemoproteus. For analysis of the feathers spectral reflectance we used both the tristimulus model and the avian tetrahedral colour space model, incorporating visual phenotype of the blue tit. Contrary to expectations we found that infected birds showed higher brightness, in both the structural and the carotenoid-based colours. We also found no differences in the feather colouration between birds infected with Plasmodium and Haemoproteus. Observed pattern might be best explained by the parasite-mediated selection hypothesis, as only individuals of superior quality should be able to survive the acute stage of infection and therefore they could produce more elaborate ornamental colouration.
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| 5. |
- Podmokla, Edyta, et al.
(author)
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Avian malaria is associated with increased reproductive investment in the blue tit
- 2014
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In: Journal of Avian Biology. - 0908-8857 .- 1600-048X. ; 45:3, s. 219-224
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Journal article (peer-reviewed)abstract
- Haemosporidians causing avian malaria are very common parasites among bird species. Their negative effects have been repeatedly reported in terms of deterioration in survival prospects or reproductive success. However, a positive association between blood parasites and avian fitness has also been reported. Here, we studied a relationship between presence of malaria parasites and reproductive performance of the host, a hole-breeding passerine - the blue tit Cyanistes caeruleus. Since the malaria parasites might affect their hosts differently depending on environmental conditions, we performed brood size manipulation experiment to differentiate parental reproductive effort and study the potential interaction between infection status and brood rearing conditions on reproductive performance. We found individuals infected with malaria parasites to breed later in the season in comparison with uninfected birds, but no differences were detected in clutch size. Interestingly, infected parents produced heavier and larger offspring with stronger reaction to phytohemagglutinin. More importantly, we found a significant interaction between infection status and brood size manipulation in offspring tarsus length and reaction to phytohemagglutinin: presence of parasites had stronger positive effect among birds caring for experimentally enlarged broods. Our results might be interpreted either in the light of the parasite-mediated selection or terminal investment hypothesis.
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| 6. |
- Podmokla, Edyta, et al.
(author)
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Determinants of prevalence and intensity of infection with malaria parasites in the Blue Tit
- 2014
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In: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375 .- 1439-0361. ; 155:3, s. 721-727
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Journal article (peer-reviewed)abstract
- Parasite species are usually specialists utilising specific host species, but parasite assemblages may differ substantially even between populations of the same species and show seasonal and annual fluctuations. Host characteristics such as individual age and sex may also affect parasite species composition and abundance. Here, we report the occurrence of malaria parasites in the Blue Tit (Cyanistes caeruleus) inhabiting Gotland (Sweden) across 5 years. Using PCR-based techniques, we found eight cytochrome b lineages belonging to genus Plasmodium (pTURUD1, pBT7, pSGS1, pSW2, pGRW11) and Haemoproteus (hPARUS1, hPHSIB1, hWW2) with the overall prevalence of 65 %. The Plasmodium infections predominated (prevalence of 49.5 %), whereas Haemoproteus infection rate was much lower (prevalence of 16.5 %). We showed significant differences in infection status between study years and age classes when all parasite lineages were analysed together or the two most common lineages were analysed separately. Overall, older birds showed higher prevalence. A significant interaction between year and genus effect significantly explained variation in infection intensity. This interaction stems from a significant yearly variation of the infection intensity with Plasmodium, while such an effect is not present for Haemoproteus infections. More importantly, the intensity of infection with Haemoproteus was significantly higher than with Plasmodium in 3 out of the 4 study years with data.
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| 7. |
- Podmokla, Edyta, et al.
(author)
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Effect of haemosporidian infections on host survival and recapture rate in the blue tit
- 2017
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In: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 48:6, s. 796-803
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Journal article (peer-reviewed)abstract
- Parasites are ubiquitous in the wild and by imposing fitness costs on their hosts they constitute an important selection factor. One of the most common parasites of wild birds are Plasmodium and Haemoproteus, protozoans inhabiting the blood, which cause avian malaria and malaria-like disease, respectively. Although they are expected to cause negative effects in infected individuals, in many cases studies in natural populations failed to detect such effect. Using data from seven breeding seasons (2008-2014), we applied a multistate capture-mark-recapture approach to study the effect of infection with malaria and malaria-like parasites, individual age and sex on the probability of survival and recapture rate in a small passerine, the blue tit Cyanistes caeruleus, inhabiting the island of Gotland, Sweden. We found no effect of infection on survival prospects. However, the recapture rate of infected individuals was higher than that of uninfected ones. Thus, while our data do not support the presence of infection costs in terms of host survival, it suggests that parasites from the genera Plasmodium and Haemoproteus may affect some aspects of host behaviour, which translates into biased estimation of infection frequency at the population level.
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| 8. |
- Podmokla, Edyta, et al.
(author)
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Malaria infection status predicts extra-pair paternity in the blue tit
- 2015
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In: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 46:3, s. 303-306
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Journal article (peer-reviewed)abstract
- Extra-pair matings comprise a common reproductive strategy among socially monogamous bird species. However, it remains unclear why females decide to mate with extra-pair males. Indirect benefits in terms of improving offspring genetic quality are usually invoked to explain this phenomenon. Parasite resistance genes are often considered as a female target of seeking extra-pair matings, but the direct test of this hypothesis is generally lacking. Here, we report on a relationship between the status of infection with malaria parasites (Plasmodium and Haemoproteus) and occurrence of extra-pair paternity in a wild population of the blue tit Cyanistes caeruleus inhabiting Gotland (Sweden). We found that the probability of extra-pair paternity is significantly related to the infection status of social parents. Infected males showed higher probability of being cuckolded than uninfected ones. However, this was observed only among males mated to uninfected females. Thus, avian malaria may potentially contribute to explanation of extra-pair mating behaviour.
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| 9. |
- Sudyka, Joanna, et al.
(author)
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Sex-specific effects of parasites on telomere dynamics in a short-lived passerinethe blue tit
- 2019
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In: The Science of Nature. - : SPRINGER HEIDELBERG. - 0028-1042 .- 1432-1904. ; 106:1-2
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Journal article (peer-reviewed)abstract
- Parasitic infections potentially drive host's life-histories since they can have detrimental effects on host's fitness. Telomere dynamics is a candidate mechanism to underlie life-history trade-offs and as such may correlate with observed fitness reduction in infected animals. We examined the relationship of chronic infection with two genera of haemosporidians causing avian malaria and malaria-like disease with host's telomere length (TL) in a longitudinal study of free-ranging blue tits. The observed overall infection prevalence was 80% and increased with age, constituting a potentially serious selective pressure in our population. We found longer telomeres in individuals infected with a parasite causing lesser blood pathologies i.e. Haemoproteus compared to Plasmodium genus, but this only held true among males. Female TL was independent of the infection type. Our results indicate that parasitic infections could bring about other types of costs to females than to males with respect to TL. Additionally, we detected linear telomere loss with age, however a random regression analysis did not confirm significant heterogeneity in TL of first breeders and telomere shortening rates in further life.
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