János Török - Academia.edu (original) (raw)

Papers by János Török

Research paper thumbnail of Interaction of climate change with effects of conspecific and heterospecific density on reproduction

Oikos

We studied the relationship between temperature and the coexistence of great tit Parus major and ... more We studied the relationship between temperature and the coexistence of great tit Parus major and blue tit Cyanistes caeruleus, breeding in 75 study plots across Europe and North Africa. We expected an advance in laying date and a reduction in clutch size during warmer springs as a general response to climate warming and a delay in laying date and a reduction in clutch size during warmer winters due to density‐dependent effects. As expected, as spring temperature increases laying date advances and as winter temperature increases clutch size is reduced in both species. Density of great tit affected the relationship between winter temperature and laying date in great and blue tit. Specifically, as density of great tit increased and temperature in winter increased both species started to reproduce later. Density of blue tit affected the relationship between spring temperature and blue and great tit laying date. Thus, both species start to reproduce earlier with increasing spring tempera...

Research paper thumbnail of White plumage color as an honest indicator: feather macrostructure links reflectance with reproductive effort and success

Behavioral Ecology and Sociobiology

The structural condition of feathers may generally have a decisive role in shaping the color prop... more The structural condition of feathers may generally have a decisive role in shaping the color properties of the plumage. However, the information content of structurally mediated color differences is poorly known. This makes it particularly hard to determine the meaning of color variation in pigment-free white plumage patches. The white wing patch of the collared flycatcher (Ficedula albicollis) is an important sexual trait, and changes in its reflectance are partly due to macrostructural condition. We used 2 years of macrostructural, reflectance, and breeding data from both sexes to examine whether wing patch macrostructure lends information content to actual reflectance in terms of reproductive effort and success. Macrostructure strongly predicted actual reflectance in males but only weakly in females. Furthermore, in males, feather vane width was related positively to current year reproductive effort, and negatively to previous year reproductive effort. This indicates that macrost...

Research paper thumbnail of Functional Integration of Multiple Sexual Ornaments: Signal Coherence and Sexual Selection

The American Naturalist

The sexual ornamentation of animals typically consists of multiple distinct traits. The classical... more The sexual ornamentation of animals typically consists of multiple distinct traits. The classical research approach focuses on differences among these traits, but this approach may often be misleading because of correlations among distinct sexual traits of similar origins. There are many published studies on the correlation structures of sexual traits, but the way receivers take into account the components of an integrated, multicomponent trait system remains mostly unknown. Here, we propose a general analytical framework to assess the possible sexual selection consequences of withinindividual coherence in the expression of multiple correlated sexual traits. We then apply this framework to a long-term mutual plumage coloration data set from a wild bird population. The results suggest that the coherence of component plumage color traits is not sexually selected. However, component trait coherence affects sexual selection on integrated plumage color. When assessing across-spectrum plumage reflectance, receivers choosing mates apparently disregard a component trait if it is inconsistent with the overall expression of other components. This indicates that separately examining and manipulating distinct sexual traits may often be misleading. Theoretical and empirical studies should further explore the effects of coherence on the ornament-preference coevolution.

Research paper thumbnail of Sequential organization of birdsong: relationships with individual quality and fitness

Behavioral Ecology, 2020

Many vocalizing animals produce the discrete elements of their acoustic signals in a specific seq... more Many vocalizing animals produce the discrete elements of their acoustic signals in a specific sequential order, but we know little about the biological relevance of this ordering. For that, we must characterize the degree by which individuals differ in how they organize their signals sequentially and relate these differences to variation in quality and fitness. In this study, we fulfilled these tasks in male collared flycatchers (Ficedula albicollis). We characterized the sequential order of syllables with a network analysis approach and studied the consistency of network variables on distinct time scales (within day, between days, and between years), and assessed their relationship with such quality indicators like age, body condition, arrival date, and fitness related proxies like survival to the next year and pairing success. We found that the syllables were associated nonrandomly with one another and both the frequency differences of consecutive syllables and the number of motif...

Research paper thumbnail of Sex-dependent risk-taking behaviour towards different predatory stimuli in the collared flycatcher

Behavioural Processes, 2021

Prey animals may react differently to predators, which can thus raise plasticity in risk-taking b... more Prey animals may react differently to predators, which can thus raise plasticity in risk-taking behaviour. We assessed the behavioural responses of nestling-feeding collared flycatcher (Ficedula albicollis) parents towards different avian predator species (Eurasian sparrowhawk, long-eared owl) and a non-threatening songbird (song thrush) by measuring the latency to resume feeding activity. We found that the sexes differed in their responses towards the different stimuli, as males resumed nestling-provisioning sooner after the songbird than after the predator stimuli, while latency of females was not affected by the type of stimulus. Parents breeding later in the season took less risk than early breeders, and mean response also varied across the study years. We detected a considerable repeatability at the within-brood level across stimuli, and a correlation between the latency of parents attending the same nest, implying that they may adjust similarly their risk-taking behaviour to the brood value. Repeated measurements at the same brood suggested that risk-taking behaviour of flycatcher parents is a plastic trait, and sex-specific effects might be the result of sex-specific adjustments of behaviour to the perceived environmental challenge as exerted by different predators. Furthermore, the nest-specific effects highlighted that environmental effects can render consistently similar responses between the parents.

Research paper thumbnail of Connecting the data landscape of long‐term ecological studies: The SPI‐Birds data hub

Journal of Animal Ecology, 2020

The integration and synthesis of the data in different areas of science is drastically slowed and... more The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long‐term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad‐scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long‐term studies of birds, we have created the SPI‐Birds Network and Database (www.spibirds.org)—a large‐scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI‐Birds has recruited over 120 members, and currentl...

Research paper thumbnail of Triparental care in the collared flycatcher (Ficedula albicollis): Cooperation of two females with a cuckolded male in rearing a brood

Ecology and Evolution, 2021

Certain predominant forms of mating and parental care systems are assumed in several model specie... more Certain predominant forms of mating and parental care systems are assumed in several model species among birds, but the opportunistic and apparently infrequent variations of “family structures” may often remain hidden due to methodological limitations with regard to genetic or behavioral observations. One of the intensively studied model species, the collared flycatcher (Ficedula albicollis), is usually characterized by social monogamy with polyterritorial, facultative social polygyny, and frequent extrapair mating and extrapair paternity. During a brood‐size manipulation experiment, we observed two females and a male delivering food at an enlarged brood. A combination of breeding phenology data (egg laying and hatching date), behavioral data (feeding rates) from video recordings at 10 days of nestling age, and microsatellite genotyping for maternity and paternity suggests a situation of an unrelated female helping a pair in chick rearing. Such observations highlight the relevance o...

Research paper thumbnail of A practical approach to measuring the acoustic diversity by community ecology methods

Methods in Ecology and Evolution, 2021

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Research paper thumbnail of Viselkedési és fiziológiai változók kapcsolata egy vadon élő énekesmadárfajnál

Állattani Közlemények, 2020

Despite the increasing number of studies describing behaviours, there are less knowledge of these... more Despite the increasing number of studies describing behaviours, there are less knowledge of these behaviour's physiological background in wild populations. In this paper we investigated the relationship between health state, oxidative damage and behaviour in a wild collared flycatcher (Ficedula albicollis) population. We defined health state as the ratio of heterophil granulocytes and limphocytes (H/L ratio). The number and ratio of leukocytes were counted in bloodsmears. Lower leukocyte ratio reflects better health state and lower stress level. We used plasma levels of reactive oxygen metabolites (ROMs) to measure oxidative damage. We collected blood samples from males during the courtship period and the chick-rearing period, while females were sampled only in the chick-rearing period. With regards to behaviour, we quantified novelty avoidance, aggression and risk-taking of males during courtship. There were no differences between sexes in H/L ratio and ROM levels. In one-year old males, ROM levels tended to be higher in the chick-rearing period. The correlation between H/L ratio and ROMs were significant only in females, namely lower oxidative damage associated with better health state. We found a correlation between novelty avoidance and ROM levels measured in the courtship period. The increase in ROMs might be caused by the demanding work of chick-rearing in one-year old males, while older males might have more experience in chick-rearing. Higher heterophil counts result in higher H/L ratio. Heterophils release radicals, which results in higher oxidative damage. Less novelty avoiding males might fly from a bigger distance to investigate novel objects getting close to its nest, resulting in a higher metabolism level, and higher plasma level of ROMs. More studies are needed for a deeper understanding of these patterns.

Research paper thumbnail of The roles of temperature, nest predators and information parasites for geographical variation in egg covering behaviour of tits (Paridae)

Journal of Biogeography, 2020

AimNest building is widespread among animals. Nests may provide receptacles for eggs, developing ... more AimNest building is widespread among animals. Nests may provide receptacles for eggs, developing offspring and the parents, and protect them from adverse environmental conditions. Nests may also indicate the quality of the territory and its owner and can be considered as an extended phenotype of its builder(s). Nests may, thus, function as a sexual and social signal. Here, we examined ecological and abiotic factors—temperature, nest predation and interspecific information utilization—shaping geographical variation in a specific nest structure—hair and feather cover of eggs—and its function as an extended phenotype before incubation in great (Parus major) and blue tits (Cyanistes caeruleus) across Europe. We also tested whether egg covering is associated with reproductive success of great tits.LocationFourteen different study sites and 28 populations across Europe.TaxonParus major, Cyanistes caeruleus.MethodsWe recorded clutch coverage estimates and collected egg covering nest materi...

Research paper thumbnail of A behavioural trait displayed in an artificial novel environment correlates with dispersal in a wild bird

Ethology, 2020

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Research paper thumbnail of Host dispersal shapes the population structure of a tick‐borne bacterial pathogen

Molecular Ecology, 2019

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of lon... more Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick‐borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies “Candidatus Borre...

Research paper thumbnail of Ornaments and condition: plumage patch sizes, nutritional reserve state, reserve accumulation, and reserve depletion

Behavioral Ecology and Sociobiology, 2019

Condition-dependence is considered as a dominant mechanism ensuring the fitness benefits of conti... more Condition-dependence is considered as a dominant mechanism ensuring the fitness benefits of continued mate choice for heritable sexual signal traits, but crucial questions remain concerning the underlying physiological pathways. For example, it is unclear whether condition-dependence is mediated by the different amount of resource obtained, some uncheatable functional link with nutritional status, or the adverse effect of nutritional stress experienced by some individuals. Furthermore, the pattern of change in nutritional reserves in relation to ornamental traits has recently been proposed as a critical pillar of the condition-dependence concept, but this pattern is virtually unknown in natural populations. We quantified separate measures for actual body condition, lipid reserve accumulation rate, and lipid reserve depletion, and applied these measures to two white plumage ornaments of male collared flycatchers during courtship, during nestling rearing, and before the summer moult. Neither actual condition nor reserve accumulation rate before moult predicted the subsequent change of ornament sizes, but reserve depletion was accompanied by the reduction of forehead patch size to the following year. Wing patch size, a trait important in territoriality, was negatively related to both reserve accumulation and reserve depletion in the courtship period, but not related to current condition. Finally, irrespective of breeding phase, measures of current condition, and recent nutritional reserve depletion were negatively correlated, but both were unrelated to resource accumulation rate. These results indicate that measuring nutritional reserve trajectories in addition to actual condition may reveal functionally important processes underlying signal-condition correlations. Significance statement Ornamental signal characters are known to convey honest information to signal receivers through their dependence on nutritional condition. Here, we show that such signals can also indicate the temporal trends of condition. We examine plumage patch sizes and separate measures of actual condition, nutritional reserve accumulation, and nutritional reserve depletion in three contexts: Communicated by A. Pilastro

Research paper thumbnail of Nest-site defence aggression during courtship does not predict nestling provisioning in male collared flycatchers

Behavioral Ecology and Sociobiology, 2019

Individuals of many animal species show consistent differences in ecologically relevant behaviour... more Individuals of many animal species show consistent differences in ecologically relevant behaviours, and these individual-specific behaviours can correlate with each other. In passerines, aggression during nest-site defence is one of those behaviours that have been steadily found to be repeatable within individuals. Furthermore, in several cases, aggression was related to some estimates of reproductive investment. Here, we studied the possibility that behaviour of males toward a male rival predicts the amount of their future parental care. This could be beneficial to the females, because during mate choice, they could use male aggressive behaviour as a cue for parental quality. We performed the study by video recording the nestling feeding activity of male collared flycatchers (Ficedula albicollis) that were assayed for aggression during the courtship period. The level of aggression was not related to feeding rate in males. Feeding rate of males differed between the study years, but it did not correlate with the feeding rate of their mates, neither was it related to the morphological traits of the parents. We may conclude that nest-site defence aggression of males does not predict their parental commitment. This may be surprising given that higher testosterone levels that may be expected in aggressive males often suppress parental care. However, among-individual variance in male testosterone profiles found to be decrease from the courtship to the parenting period in flycatchers, and this may explain why differences in territorial aggression did not manifest in differences in nestling provisioning. The correlation between behaviours that are expressed in distinct periods of the annual cycle of songbirds needs further investigation. Significance statement Male songbirds, when attracting mates, are often confronted with each other over nest-sites, and these male-male confrontations may be witnessed by females. If performance during territory defence predicts the quality of parental care that a male will provide for its nestlings, females could use defence behaviour as a cue for mate choice. To explore this possibility, we investigated the relationship between territorial aggression and nestling feeding activity of male collared flycatchers. We performed simulated territorial intrusions to measure the aggression of males and recorded their nestling feeding rate about a month later. We found that territorial aggression did not correlate with nestling feeding rate. This suggests that nest-site defence behaviour in the beginning of the breeding season does not carry information for females about what to expect from potential mates in terms of parental care.

Research paper thumbnail of Male territorial aggression and fitness in collared flycatchers: a long-term study

The Science of Nature, 2019

Aggressive behaviour plays a fundamental role in the distribution of limiting resources. Thereby,... more Aggressive behaviour plays a fundamental role in the distribution of limiting resources. Thereby, it is expected to have consequences for fitness. Here, we explored the relationship between aggression and fitness in a long-term database collected in a wild population of the collared flycatcher (Ficedula albicollis). We quantified the aggression of males during nest-site defence by conducting simulated territorial intrusions in the courtship period. We estimated the fitness of males based on their pairing success, breeding output and survival to next year. Earlier arriving and older males had a higher probability to establish pairbond, and males that started to breed earlier fledged more young. Aggression did not predict pairing and breeding performances. However, the probability of a male to return in the next year was significantly related to aggression in an age-dependent manner. Among subadult males, more aggressive individuals had higher chances to return, while among adult males, less aggressive ones did so. This finding is in harmony with our general observation that subadult collared flycatcher males behave more aggressively than adult males when confronted with a conspecific intruder. Subadult males may be socially inexperienced, so they should be more aggressive to be successful. In contrast, if adult males suffer from higher physiological costs, a lower level of aggression may be more advantageous for them. Our study shows that aggressive behaviour can be a fitness-related trait, and to understand its role in determining fitness, age should be taken into account.

Research paper thumbnail of Unravelling the relationships between life history, behaviour and condition under the pace-of-life syndromes hypothesis using long-term data from a wild bird

Behavioral Ecology and Sociobiology, 2018

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Research paper thumbnail of When to measure plumage reflectance: a lesson from Collared Flycatchers Ficedula albicollis

Ibis, 2018

Sexually selected colour traits of bird plumage are widely studied. Although the plumage is repla... more Sexually selected colour traits of bird plumage are widely studied. Although the plumage is replaced only at one or two yearly moults, plumage colour has long been shown to change between moults. Nevertheless, most studies measure colour weeks to months after the courtship period, typically at nestling rearing, and it is unclear whether these measurements yield relevant data concerning the primary process of sexual selection. Here we analyse repeated spectrometric data taken from male Collared Flycatchers during social courtship and nestling rearing. We show that some spectral traits are not correlated between the two measurements and that within‐individual correlation declines significantly with the likely exposure of the plumage area to damage and soiling. There is an overall decline in spectral trait exaggeration during breeding, but trait decline is not closely related to measurement latency, especially not in the damage‐exposed areas. Finally, sexual selection estimates differ ...

Research paper thumbnail of Mutual plumage ornamentation and biparental care: consequences for success in different environments

Behavioral Ecology, 2017

According to the good parent and differential allocation models, parental behavior could depend o... more According to the good parent and differential allocation models, parental behavior could depend on the individual's own quality, and it could be adjusted to the coinvestor's parental care and sexual ornamentation. These investment patterns may interact with environmental conditions and offspring quality in determining reproductive success. Few studies have considered ornament-related own and partner care of both parents and their consequences in relation to environmental conditions. In a brood size manipulation experiment on collared flycatchers (Ficedula albicollis), we measured nestling feeding rates, white patch sizes and plumage reflectance properties of both parents, and quantified nestling growth and reproductive success. We found little relationship between ornamentation and own feeding rate irrespective of manipulation. Parental quality, measured as nestling biomass production per unit feeding effort, was related to male structural plumage brightness in a manipulation-dependent manner. Male wing patch size and the female's structural plumage brightness were linked to the partner's feeding rate, and this did not vary with experimental environment. Finally, relationship of prefledging nestling size with male forehead patch size was environment-dependent, and this pattern was apparently due to intrinsic nestling characteristics. Reproductive success only partly reflected these findings. Our results indicate how integrated studies of mutual ornamentation and mutual care with environmental and offspring quality may help us better grasp the selection forces shaping sexual ornaments.

Research paper thumbnail of A kulturális evolúció nyomai az örvös légykapó (Ficedula albicollis) énekében

Állattani Közlemények, 2016

Research paper thumbnail of Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

Biological Journal of the Linnean Society, 2016

Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogeni... more Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing population genetic structure at different spatial scales is thus a crucial step towards understanding mechanisms underlying intraspecific differentiation and diversification. Here, we studied the population genetic structure of a highly mobile speciesthe great tit Parus majorat different spatial scales. We analysed 884 individuals from 30 sites across Europe including 10 close-by sites (< 50 km), using 22 microsatellite markers. Overall we found a low but significant genetic differentiation among sites (F ST = 0.008). Genetic differentiation was higher, and genetic diversity lower, in southwestern Europe. These regional differences were statistically best explained by winter temperature. Overall, our results suggest that great tits form a single patchy metapopulation across Europe, in which genetic differentiation is independent of geographical distance and gene flow may be regulated by environmental factors via movements related to winter severity. This might have important implications for the evolutionary trajectories of sub-populations, especially in the context of climate change, and calls for future investigations of local differences in costs and benefits of philopatry at large scales. Pentzold et al., 2013). In contrast, all western-European great tits share a common haplotype, suggesting that they originate from a single glacial refugium located in southern Europe (Kvist et al., 2007; Kvist et al., 1999; Pavlova et al., 2006, Fig. S1, Table S1). Therefore genetic differentiation in great tits estimated with microsatellites that evolve faster than mtDNA and are more powerful to detect recent and local micro-evolutionary processes among populations, are less likely to result from past genetic discontinuities across different glacial refugia as is the case for many other species (e.g. Hewitt, 2000; Kvist et al., 1999). Using 22 microsatellite markers, we investigated population genetic diversity and structure, as well as the scale of genetic differentiation, in great tits by sampling 30 sites across Europe including 10 close-by (i.e. up to 50 km) sites. We expected the genetic differentiation to be correlated with the geographical distance either at small or large scales: the studied geographical scale should allow us to determine at which scale isolation-bydistance would occur in great tits. In addition, a signal of historical range expansion from the South to the North should result in decreased genetic diversity with increasing latitude. In a second step, we explored the influence of environmental factors on the observed genetic diversity and differentiation patterns, focusing on factors that can be expected to affect individual movement. In particular, temperature may strongly shape genetic differentiation among populations by acting on both dispersal movements (e.g. Parn et al., 2012) and establishment success (i.e. survival and reproductive success after settlement) of long-distance immigrants (e.g. Van Doorslaer et al., 2009). Three different patterns may thus be predicted in relation to temperature. First, because temperature can be positively correlated with survival and population density (Ahola et al., 2009; Garant et al., 2004; Parn et al., 2012) that increase dispersal propensities (Forsman & Monkkonen, 2003; Matthysen, 2005), genetic diversity could increase and genetic differentiation decrease with increasing temperature. Second, a negative relationship between temperature and dispersal propensities may be expected in the case of partial migration (e.g. Nilsson et al., 2006). In this case, temperature should relate to Purcell JFH, Cowen RK, Hughes CR, Williams DA. 2006. Weak genetic structure indicates strong dispersal limits: a tale of two coral reef fish.

Research paper thumbnail of Interaction of climate change with effects of conspecific and heterospecific density on reproduction

Oikos

We studied the relationship between temperature and the coexistence of great tit Parus major and ... more We studied the relationship between temperature and the coexistence of great tit Parus major and blue tit Cyanistes caeruleus, breeding in 75 study plots across Europe and North Africa. We expected an advance in laying date and a reduction in clutch size during warmer springs as a general response to climate warming and a delay in laying date and a reduction in clutch size during warmer winters due to density‐dependent effects. As expected, as spring temperature increases laying date advances and as winter temperature increases clutch size is reduced in both species. Density of great tit affected the relationship between winter temperature and laying date in great and blue tit. Specifically, as density of great tit increased and temperature in winter increased both species started to reproduce later. Density of blue tit affected the relationship between spring temperature and blue and great tit laying date. Thus, both species start to reproduce earlier with increasing spring tempera...

Research paper thumbnail of White plumage color as an honest indicator: feather macrostructure links reflectance with reproductive effort and success

Behavioral Ecology and Sociobiology

The structural condition of feathers may generally have a decisive role in shaping the color prop... more The structural condition of feathers may generally have a decisive role in shaping the color properties of the plumage. However, the information content of structurally mediated color differences is poorly known. This makes it particularly hard to determine the meaning of color variation in pigment-free white plumage patches. The white wing patch of the collared flycatcher (Ficedula albicollis) is an important sexual trait, and changes in its reflectance are partly due to macrostructural condition. We used 2 years of macrostructural, reflectance, and breeding data from both sexes to examine whether wing patch macrostructure lends information content to actual reflectance in terms of reproductive effort and success. Macrostructure strongly predicted actual reflectance in males but only weakly in females. Furthermore, in males, feather vane width was related positively to current year reproductive effort, and negatively to previous year reproductive effort. This indicates that macrost...

Research paper thumbnail of Functional Integration of Multiple Sexual Ornaments: Signal Coherence and Sexual Selection

The American Naturalist

The sexual ornamentation of animals typically consists of multiple distinct traits. The classical... more The sexual ornamentation of animals typically consists of multiple distinct traits. The classical research approach focuses on differences among these traits, but this approach may often be misleading because of correlations among distinct sexual traits of similar origins. There are many published studies on the correlation structures of sexual traits, but the way receivers take into account the components of an integrated, multicomponent trait system remains mostly unknown. Here, we propose a general analytical framework to assess the possible sexual selection consequences of withinindividual coherence in the expression of multiple correlated sexual traits. We then apply this framework to a long-term mutual plumage coloration data set from a wild bird population. The results suggest that the coherence of component plumage color traits is not sexually selected. However, component trait coherence affects sexual selection on integrated plumage color. When assessing across-spectrum plumage reflectance, receivers choosing mates apparently disregard a component trait if it is inconsistent with the overall expression of other components. This indicates that separately examining and manipulating distinct sexual traits may often be misleading. Theoretical and empirical studies should further explore the effects of coherence on the ornament-preference coevolution.

Research paper thumbnail of Sequential organization of birdsong: relationships with individual quality and fitness

Behavioral Ecology, 2020

Many vocalizing animals produce the discrete elements of their acoustic signals in a specific seq... more Many vocalizing animals produce the discrete elements of their acoustic signals in a specific sequential order, but we know little about the biological relevance of this ordering. For that, we must characterize the degree by which individuals differ in how they organize their signals sequentially and relate these differences to variation in quality and fitness. In this study, we fulfilled these tasks in male collared flycatchers (Ficedula albicollis). We characterized the sequential order of syllables with a network analysis approach and studied the consistency of network variables on distinct time scales (within day, between days, and between years), and assessed their relationship with such quality indicators like age, body condition, arrival date, and fitness related proxies like survival to the next year and pairing success. We found that the syllables were associated nonrandomly with one another and both the frequency differences of consecutive syllables and the number of motif...

Research paper thumbnail of Sex-dependent risk-taking behaviour towards different predatory stimuli in the collared flycatcher

Behavioural Processes, 2021

Prey animals may react differently to predators, which can thus raise plasticity in risk-taking b... more Prey animals may react differently to predators, which can thus raise plasticity in risk-taking behaviour. We assessed the behavioural responses of nestling-feeding collared flycatcher (Ficedula albicollis) parents towards different avian predator species (Eurasian sparrowhawk, long-eared owl) and a non-threatening songbird (song thrush) by measuring the latency to resume feeding activity. We found that the sexes differed in their responses towards the different stimuli, as males resumed nestling-provisioning sooner after the songbird than after the predator stimuli, while latency of females was not affected by the type of stimulus. Parents breeding later in the season took less risk than early breeders, and mean response also varied across the study years. We detected a considerable repeatability at the within-brood level across stimuli, and a correlation between the latency of parents attending the same nest, implying that they may adjust similarly their risk-taking behaviour to the brood value. Repeated measurements at the same brood suggested that risk-taking behaviour of flycatcher parents is a plastic trait, and sex-specific effects might be the result of sex-specific adjustments of behaviour to the perceived environmental challenge as exerted by different predators. Furthermore, the nest-specific effects highlighted that environmental effects can render consistently similar responses between the parents.

Research paper thumbnail of Connecting the data landscape of long‐term ecological studies: The SPI‐Birds data hub

Journal of Animal Ecology, 2020

The integration and synthesis of the data in different areas of science is drastically slowed and... more The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long‐term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad‐scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long‐term studies of birds, we have created the SPI‐Birds Network and Database (www.spibirds.org)—a large‐scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI‐Birds has recruited over 120 members, and currentl...

Research paper thumbnail of Triparental care in the collared flycatcher (Ficedula albicollis): Cooperation of two females with a cuckolded male in rearing a brood

Ecology and Evolution, 2021

Certain predominant forms of mating and parental care systems are assumed in several model specie... more Certain predominant forms of mating and parental care systems are assumed in several model species among birds, but the opportunistic and apparently infrequent variations of “family structures” may often remain hidden due to methodological limitations with regard to genetic or behavioral observations. One of the intensively studied model species, the collared flycatcher (Ficedula albicollis), is usually characterized by social monogamy with polyterritorial, facultative social polygyny, and frequent extrapair mating and extrapair paternity. During a brood‐size manipulation experiment, we observed two females and a male delivering food at an enlarged brood. A combination of breeding phenology data (egg laying and hatching date), behavioral data (feeding rates) from video recordings at 10 days of nestling age, and microsatellite genotyping for maternity and paternity suggests a situation of an unrelated female helping a pair in chick rearing. Such observations highlight the relevance o...

Research paper thumbnail of A practical approach to measuring the acoustic diversity by community ecology methods

Methods in Ecology and Evolution, 2021

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Research paper thumbnail of Viselkedési és fiziológiai változók kapcsolata egy vadon élő énekesmadárfajnál

Állattani Közlemények, 2020

Despite the increasing number of studies describing behaviours, there are less knowledge of these... more Despite the increasing number of studies describing behaviours, there are less knowledge of these behaviour's physiological background in wild populations. In this paper we investigated the relationship between health state, oxidative damage and behaviour in a wild collared flycatcher (Ficedula albicollis) population. We defined health state as the ratio of heterophil granulocytes and limphocytes (H/L ratio). The number and ratio of leukocytes were counted in bloodsmears. Lower leukocyte ratio reflects better health state and lower stress level. We used plasma levels of reactive oxygen metabolites (ROMs) to measure oxidative damage. We collected blood samples from males during the courtship period and the chick-rearing period, while females were sampled only in the chick-rearing period. With regards to behaviour, we quantified novelty avoidance, aggression and risk-taking of males during courtship. There were no differences between sexes in H/L ratio and ROM levels. In one-year old males, ROM levels tended to be higher in the chick-rearing period. The correlation between H/L ratio and ROMs were significant only in females, namely lower oxidative damage associated with better health state. We found a correlation between novelty avoidance and ROM levels measured in the courtship period. The increase in ROMs might be caused by the demanding work of chick-rearing in one-year old males, while older males might have more experience in chick-rearing. Higher heterophil counts result in higher H/L ratio. Heterophils release radicals, which results in higher oxidative damage. Less novelty avoiding males might fly from a bigger distance to investigate novel objects getting close to its nest, resulting in a higher metabolism level, and higher plasma level of ROMs. More studies are needed for a deeper understanding of these patterns.

Research paper thumbnail of The roles of temperature, nest predators and information parasites for geographical variation in egg covering behaviour of tits (Paridae)

Journal of Biogeography, 2020

AimNest building is widespread among animals. Nests may provide receptacles for eggs, developing ... more AimNest building is widespread among animals. Nests may provide receptacles for eggs, developing offspring and the parents, and protect them from adverse environmental conditions. Nests may also indicate the quality of the territory and its owner and can be considered as an extended phenotype of its builder(s). Nests may, thus, function as a sexual and social signal. Here, we examined ecological and abiotic factors—temperature, nest predation and interspecific information utilization—shaping geographical variation in a specific nest structure—hair and feather cover of eggs—and its function as an extended phenotype before incubation in great (Parus major) and blue tits (Cyanistes caeruleus) across Europe. We also tested whether egg covering is associated with reproductive success of great tits.LocationFourteen different study sites and 28 populations across Europe.TaxonParus major, Cyanistes caeruleus.MethodsWe recorded clutch coverage estimates and collected egg covering nest materi...

Research paper thumbnail of A behavioural trait displayed in an artificial novel environment correlates with dispersal in a wild bird

Ethology, 2020

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Research paper thumbnail of Host dispersal shapes the population structure of a tick‐borne bacterial pathogen

Molecular Ecology, 2019

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of lon... more Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick‐borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies “Candidatus Borre...

Research paper thumbnail of Ornaments and condition: plumage patch sizes, nutritional reserve state, reserve accumulation, and reserve depletion

Behavioral Ecology and Sociobiology, 2019

Condition-dependence is considered as a dominant mechanism ensuring the fitness benefits of conti... more Condition-dependence is considered as a dominant mechanism ensuring the fitness benefits of continued mate choice for heritable sexual signal traits, but crucial questions remain concerning the underlying physiological pathways. For example, it is unclear whether condition-dependence is mediated by the different amount of resource obtained, some uncheatable functional link with nutritional status, or the adverse effect of nutritional stress experienced by some individuals. Furthermore, the pattern of change in nutritional reserves in relation to ornamental traits has recently been proposed as a critical pillar of the condition-dependence concept, but this pattern is virtually unknown in natural populations. We quantified separate measures for actual body condition, lipid reserve accumulation rate, and lipid reserve depletion, and applied these measures to two white plumage ornaments of male collared flycatchers during courtship, during nestling rearing, and before the summer moult. Neither actual condition nor reserve accumulation rate before moult predicted the subsequent change of ornament sizes, but reserve depletion was accompanied by the reduction of forehead patch size to the following year. Wing patch size, a trait important in territoriality, was negatively related to both reserve accumulation and reserve depletion in the courtship period, but not related to current condition. Finally, irrespective of breeding phase, measures of current condition, and recent nutritional reserve depletion were negatively correlated, but both were unrelated to resource accumulation rate. These results indicate that measuring nutritional reserve trajectories in addition to actual condition may reveal functionally important processes underlying signal-condition correlations. Significance statement Ornamental signal characters are known to convey honest information to signal receivers through their dependence on nutritional condition. Here, we show that such signals can also indicate the temporal trends of condition. We examine plumage patch sizes and separate measures of actual condition, nutritional reserve accumulation, and nutritional reserve depletion in three contexts: Communicated by A. Pilastro

Research paper thumbnail of Nest-site defence aggression during courtship does not predict nestling provisioning in male collared flycatchers

Behavioral Ecology and Sociobiology, 2019

Individuals of many animal species show consistent differences in ecologically relevant behaviour... more Individuals of many animal species show consistent differences in ecologically relevant behaviours, and these individual-specific behaviours can correlate with each other. In passerines, aggression during nest-site defence is one of those behaviours that have been steadily found to be repeatable within individuals. Furthermore, in several cases, aggression was related to some estimates of reproductive investment. Here, we studied the possibility that behaviour of males toward a male rival predicts the amount of their future parental care. This could be beneficial to the females, because during mate choice, they could use male aggressive behaviour as a cue for parental quality. We performed the study by video recording the nestling feeding activity of male collared flycatchers (Ficedula albicollis) that were assayed for aggression during the courtship period. The level of aggression was not related to feeding rate in males. Feeding rate of males differed between the study years, but it did not correlate with the feeding rate of their mates, neither was it related to the morphological traits of the parents. We may conclude that nest-site defence aggression of males does not predict their parental commitment. This may be surprising given that higher testosterone levels that may be expected in aggressive males often suppress parental care. However, among-individual variance in male testosterone profiles found to be decrease from the courtship to the parenting period in flycatchers, and this may explain why differences in territorial aggression did not manifest in differences in nestling provisioning. The correlation between behaviours that are expressed in distinct periods of the annual cycle of songbirds needs further investigation. Significance statement Male songbirds, when attracting mates, are often confronted with each other over nest-sites, and these male-male confrontations may be witnessed by females. If performance during territory defence predicts the quality of parental care that a male will provide for its nestlings, females could use defence behaviour as a cue for mate choice. To explore this possibility, we investigated the relationship between territorial aggression and nestling feeding activity of male collared flycatchers. We performed simulated territorial intrusions to measure the aggression of males and recorded their nestling feeding rate about a month later. We found that territorial aggression did not correlate with nestling feeding rate. This suggests that nest-site defence behaviour in the beginning of the breeding season does not carry information for females about what to expect from potential mates in terms of parental care.

Research paper thumbnail of Male territorial aggression and fitness in collared flycatchers: a long-term study

The Science of Nature, 2019

Aggressive behaviour plays a fundamental role in the distribution of limiting resources. Thereby,... more Aggressive behaviour plays a fundamental role in the distribution of limiting resources. Thereby, it is expected to have consequences for fitness. Here, we explored the relationship between aggression and fitness in a long-term database collected in a wild population of the collared flycatcher (Ficedula albicollis). We quantified the aggression of males during nest-site defence by conducting simulated territorial intrusions in the courtship period. We estimated the fitness of males based on their pairing success, breeding output and survival to next year. Earlier arriving and older males had a higher probability to establish pairbond, and males that started to breed earlier fledged more young. Aggression did not predict pairing and breeding performances. However, the probability of a male to return in the next year was significantly related to aggression in an age-dependent manner. Among subadult males, more aggressive individuals had higher chances to return, while among adult males, less aggressive ones did so. This finding is in harmony with our general observation that subadult collared flycatcher males behave more aggressively than adult males when confronted with a conspecific intruder. Subadult males may be socially inexperienced, so they should be more aggressive to be successful. In contrast, if adult males suffer from higher physiological costs, a lower level of aggression may be more advantageous for them. Our study shows that aggressive behaviour can be a fitness-related trait, and to understand its role in determining fitness, age should be taken into account.

Research paper thumbnail of Unravelling the relationships between life history, behaviour and condition under the pace-of-life syndromes hypothesis using long-term data from a wild bird

Behavioral Ecology and Sociobiology, 2018

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Research paper thumbnail of When to measure plumage reflectance: a lesson from Collared Flycatchers Ficedula albicollis

Ibis, 2018

Sexually selected colour traits of bird plumage are widely studied. Although the plumage is repla... more Sexually selected colour traits of bird plumage are widely studied. Although the plumage is replaced only at one or two yearly moults, plumage colour has long been shown to change between moults. Nevertheless, most studies measure colour weeks to months after the courtship period, typically at nestling rearing, and it is unclear whether these measurements yield relevant data concerning the primary process of sexual selection. Here we analyse repeated spectrometric data taken from male Collared Flycatchers during social courtship and nestling rearing. We show that some spectral traits are not correlated between the two measurements and that within‐individual correlation declines significantly with the likely exposure of the plumage area to damage and soiling. There is an overall decline in spectral trait exaggeration during breeding, but trait decline is not closely related to measurement latency, especially not in the damage‐exposed areas. Finally, sexual selection estimates differ ...

Research paper thumbnail of Mutual plumage ornamentation and biparental care: consequences for success in different environments

Behavioral Ecology, 2017

According to the good parent and differential allocation models, parental behavior could depend o... more According to the good parent and differential allocation models, parental behavior could depend on the individual's own quality, and it could be adjusted to the coinvestor's parental care and sexual ornamentation. These investment patterns may interact with environmental conditions and offspring quality in determining reproductive success. Few studies have considered ornament-related own and partner care of both parents and their consequences in relation to environmental conditions. In a brood size manipulation experiment on collared flycatchers (Ficedula albicollis), we measured nestling feeding rates, white patch sizes and plumage reflectance properties of both parents, and quantified nestling growth and reproductive success. We found little relationship between ornamentation and own feeding rate irrespective of manipulation. Parental quality, measured as nestling biomass production per unit feeding effort, was related to male structural plumage brightness in a manipulation-dependent manner. Male wing patch size and the female's structural plumage brightness were linked to the partner's feeding rate, and this did not vary with experimental environment. Finally, relationship of prefledging nestling size with male forehead patch size was environment-dependent, and this pattern was apparently due to intrinsic nestling characteristics. Reproductive success only partly reflected these findings. Our results indicate how integrated studies of mutual ornamentation and mutual care with environmental and offspring quality may help us better grasp the selection forces shaping sexual ornaments.

Research paper thumbnail of A kulturális evolúció nyomai az örvös légykapó (Ficedula albicollis) énekében

Állattani Közlemények, 2016

Research paper thumbnail of Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

Biological Journal of the Linnean Society, 2016

Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogeni... more Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing population genetic structure at different spatial scales is thus a crucial step towards understanding mechanisms underlying intraspecific differentiation and diversification. Here, we studied the population genetic structure of a highly mobile speciesthe great tit Parus majorat different spatial scales. We analysed 884 individuals from 30 sites across Europe including 10 close-by sites (< 50 km), using 22 microsatellite markers. Overall we found a low but significant genetic differentiation among sites (F ST = 0.008). Genetic differentiation was higher, and genetic diversity lower, in southwestern Europe. These regional differences were statistically best explained by winter temperature. Overall, our results suggest that great tits form a single patchy metapopulation across Europe, in which genetic differentiation is independent of geographical distance and gene flow may be regulated by environmental factors via movements related to winter severity. This might have important implications for the evolutionary trajectories of sub-populations, especially in the context of climate change, and calls for future investigations of local differences in costs and benefits of philopatry at large scales. Pentzold et al., 2013). In contrast, all western-European great tits share a common haplotype, suggesting that they originate from a single glacial refugium located in southern Europe (Kvist et al., 2007; Kvist et al., 1999; Pavlova et al., 2006, Fig. S1, Table S1). Therefore genetic differentiation in great tits estimated with microsatellites that evolve faster than mtDNA and are more powerful to detect recent and local micro-evolutionary processes among populations, are less likely to result from past genetic discontinuities across different glacial refugia as is the case for many other species (e.g. Hewitt, 2000; Kvist et al., 1999). Using 22 microsatellite markers, we investigated population genetic diversity and structure, as well as the scale of genetic differentiation, in great tits by sampling 30 sites across Europe including 10 close-by (i.e. up to 50 km) sites. We expected the genetic differentiation to be correlated with the geographical distance either at small or large scales: the studied geographical scale should allow us to determine at which scale isolation-bydistance would occur in great tits. In addition, a signal of historical range expansion from the South to the North should result in decreased genetic diversity with increasing latitude. In a second step, we explored the influence of environmental factors on the observed genetic diversity and differentiation patterns, focusing on factors that can be expected to affect individual movement. In particular, temperature may strongly shape genetic differentiation among populations by acting on both dispersal movements (e.g. Parn et al., 2012) and establishment success (i.e. survival and reproductive success after settlement) of long-distance immigrants (e.g. Van Doorslaer et al., 2009). Three different patterns may thus be predicted in relation to temperature. First, because temperature can be positively correlated with survival and population density (Ahola et al., 2009; Garant et al., 2004; Parn et al., 2012) that increase dispersal propensities (Forsman & Monkkonen, 2003; Matthysen, 2005), genetic diversity could increase and genetic differentiation decrease with increasing temperature. Second, a negative relationship between temperature and dispersal propensities may be expected in the case of partial migration (e.g. Nilsson et al., 2006). In this case, temperature should relate to Purcell JFH, Cowen RK, Hughes CR, Williams DA. 2006. Weak genetic structure indicates strong dispersal limits: a tale of two coral reef fish.