Evolutionary Ecology Associate Research Unit CSIC

Barcelona, Spain

Evolutionary Ecology Associate Research Unit CSIC

Barcelona, Spain
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Riyahi S.,Ferdowsi University of Mashhad | Riyahi S.,Evolutionary Ecology Associate Research Unit CSIC | Hammer O.,University of Oslo | Arbabi T.,Institute of Pharmacy and Molecular Biotechnology | And 4 more authors.
BMC Evolutionary Biology | Year: 2013

Background: The granivorous house sparrow Passer domesticus is thought to have developed its commensal relationship with humans with the rise of agriculture in the Middle East some 10,000 years ago, and to have expanded with the spread of agriculture in Eurasia during the last few thousand years. One subspecies, P. d. bactrianus, residing in Central Asia, has apparently maintained the ancestral ecology, however. This subspecies is not associated with human settlements; it is migratory and lives in natural grass- and wetland habitats feeding on wild grass seeds. It is well documented that the agricultural revolution was associated with an increase in grain size and changes in seed structure in cultivated cereals, the preferred food source of commensal house sparrow. Accordingly, we hypothesize that correlated changes may have occurred in beak and skull morphology as adaptive responses to the change in diet. Here, we test this hypothesis by comparing the skull shapes of 101 house sparrows from Iran, belonging to five different subspecies, including the non-commensal P. d. bactrianus, using geometric morphometrics. Results: The various commensal house sparrow subspecies share subtle but consistent skeletal features that differ significantly from those of the non-commensal P. d. bactrianus. Although there is a marked overall size allometry in the data set, the shape difference between the ecologically differentiated sparrows cannot be explained by differences in size alone. Relative to the size allometry commensal house sparrows exhibit a skull shape consistent with accelerated development (heterochrony), resulting in a more robust facial cranium and a larger, more pointed beak. Conclusion: The difference in skull shape and robustness of the beak between commensal and non-commensal house sparrows is consistent with adaptations to process the larger and rachis encapsulated seeds of domesticated cereals among human associated populations. © 2013 Riyahi et al.; licensee BioMed Central Ltd.

Del Val E.,Evolutionary Ecology Associate Research Unit CSIC | Quesada J.,Evolutionary Ecology Associate Research Unit CSIC | Quesada J.,Catalan Ornithological Institute | Senar J.C.,Evolutionary Ecology Associate Research Unit CSIC
Ardea | Year: 2010

Adult birds usually display brighter plumage coloration than younger individuals. This difference may be either due to selection against less coloured yearlings or to an increase in coloration after their first complete moult. In this study, we examined age-related differences in carotenoid-based yellow ventral coloration of Great Tits Parus major. Cross-sectional analyses at the population level showed that older males are in general greener and more saturated in colour than yearling individuals. Longitudinal analyses using birds captured in subsequent seasons confirmed within-individual changes in coloration with age. Such increase in coloration might be the result of the development of better foraging skills with age- and hence, the individual ability to obtain enough carotenoid-rich sources at the time of moult-, or consequence of other factors indirectly associated with age. However, we cannot rule out the possibility that other factors (such as directional selection against less coloured individuals) operate additionally at the population level.

Pagani-Nunez E.,Evolutionary Ecology Associate Research Unit CSIC | Ruiz I.,Evolutionary Ecology Associate Research Unit CSIC | Quesada J.,Evolutionary Ecology Associate Research Unit CSIC | Negro J.J.,CSIC - Doñana Biological Station | Senar J.C.,Evolutionary Ecology Associate Research Unit CSIC
Animal Biodiversity and Conservation | Year: 2011

The diet of the Great Tit Parus major when rearing chicks has been described in many studies. However, data from the Mediterranean area is scarce. Here we describe the diet of nestlings in a population of Great Tits in a Mediterranean forest in Barcelona (north-east Spain) during two breeding seasons using two methods: neck-collars and video recording. The main prey were caterpillars (44% from neck-collar data and 62% from video-recorded data), but in our latitudes spiders also seemed to be an important food resource (24% from neck-collar data and 42% from video-recorded data). We did not find any significant differences in the quantity of spiders collected by parents in relation to stage of chick development, main vegetation surrounding nest boxes, size of the brood, or year. Our results stress the importance of spiders as a food source in Mediterranean habitats. © 2011 Museu de Ciències Naturals de Barcelona.

Pagani-Nunez E.,Evolutionary Ecology Associate Research Unit CSIC | Pagani-Nunez E.,Guangxi University | Valls M.,Evolutionary Ecology Associate Research Unit CSIC | Senar J.C.,Evolutionary Ecology Associate Research Unit CSIC
Oecologia | Year: 2015

The analysis of diet specialization provides key information on how different individuals deal with similar food and habitat constraints within populations. Characterizing parental diet specialization at the moment of breeding, and the consistency of these preferences under different levels of effort, may help us to understand why parents exploit alternative resources. We investigated these questions in a species commonly considered a generalist: a breeding population of Mediterranean great tits Parus major. Our aim was to determine whether they are specialists or generalists at the pair level, and the consistency of this behaviour under different levels of effort. Using proportional similarity and mean pairwise overlap indices, we found that parents showed great variability in prey selection between territories. That is, they displayed a small niche overlap. Interestingly, the most specialized breeding pairs showed a tendency to have larger broods. Additionally, we experimentally manipulated brood size and found that parents showed high short-term consistency in their foraging behaviour. They precisely adjusted the number of provisioning trips to the number of nestlings, while they were unable to modify prey proportions or prey size after brood size was changed. We can therefore characterize their foraging strategies as highly consistent. Our results suggest that although the great tit may be considered a generalist at the species or population level, there was a tendency for trophic specialization among breeding pairs. This high inter- and intrapopulation plasticity could account for their great success and wide distribution. © 2015 Springer-Verlag Berlin Heidelberg

Pagani-Nunez E.,Evolutionary Ecology Associate Research Unit CSIC | Hernandez-Gomez S.,Grup Danellament Parus
Revista Catalana d'Ornitologia | Year: 2013

Inter-individual differences in the extent of post-juvenile moult in migratory birds are usually attributed to energetic or time constraints that are related to their different geographic origins. In addition, recent research has stressed the importance of food availability in the moult and migratory strategies of birds. Consequently, individual quality and foraging ability will affect both moult extent and body condition. We thus hypothesized that these two variables could be influenced by the same factors and could be correlated in winter. We tested whether the extent of post-juvenile moult was associated with the body condition (body mass, muscle and fat scores) and related variables (tarsus and bill length) of forty-six male Common Chiffchaffs Phylloscopus collybita wintering in the Mediterranean area. We found no correlation between moult extent and body mass. Nevertheless, Common Chiffchaffs with longer bills and higher fat scores did have better body condition and moulted more flight feathers. The number of flight and contour feathers that were moulted increased as the season progressed, whereas body mass varied on a daily basis. Our results support the idea that individual quality influences post-juvenile moult and winter performance and suggest that juvenile Common Chiffchaffs with longer bills have different foraging strategies that enable some individuals to improve their performance.

Riyahi S.,Evolutionary Ecology Associate Research Unit CSIC | Bjorklund M.,Uppsala University | Odeen A.,Uppsala University | Senar J.C.,Evolutionary Ecology Associate Research Unit CSIC
Bird Study | Year: 2015

Capsule The Great Tit Parus major displays a black melanin breast patch stripe (black tie or black belly stripe) which shows great variation and its size correlates with male breeding success, survival and dominance. We investigated for associations between the melanocortin-1 receptor (MC1R) polymorphism, which has an important function in melanin colouration, and the size of the black belly stripe but were unable to detect any polymorphism in this gene. Variation in the size of the melanin-based black belly stripe may therefore be regulated through genetic variation at other genes or via modification of the gene expression inside the melanocortin system and melanogenesis. © 2014 British Trust for Ornithology

Pagani-Nunez E.,Evolutionary Ecology Associate Research Unit CSIC | Hernandez-Gomez S.,Evolutionary Ecology Associate Research Unit CSIC | Riyahi S.,Evolutionary Ecology Associate Research Unit CSIC | Senar J.-C.,Evolutionary Ecology Associate Research Unit CSIC
Ardeola | Year: 2014

A key topic in foraging ecology is whether a particular prey type is consumed because it is more abundant or easier to catch, or because there is a specific preference for it. The great tit Parus major is an ideal species for studying this topic. Although it is traditionally regarded as a caterpillar specialist, in certain periods, e.g. during the breeding season, or areas, such as the Mediterranean forests, the great tit seems to show a preference for spiders. We conducted food choice experiments with captive birds to ascertain which of these two main prey types (caterpillars vs. spiders) was preferred outside the breeding season when there was an opportunity to prey on both food types. In conclusion, we found that, regardless of any variation in the supply-demand ratio and the amount of food available, Mediterranean great tits showed a preference for spiders.

Pagani-Nunez E.,Evolutionary Ecology Associate Research Unit CSIC | Uribe F.,Evolutionary Ecology Associate Research Unit CSIC | Hernandez-Gomez S.,Evolutionary Ecology Associate Research Unit CSIC | Munoz G.,Evolutionary Ecology Associate Research Unit CSIC | Senar J.C.,Evolutionary Ecology Associate Research Unit CSIC
Biological Journal of the Linnean Society | Year: 2014

Carotenoid-based coloration of nestling plumage is generally considered a reliable signal of quality and has consistently been related to habitat structure. The main hypothesis proposed to explain this correlation is that high quality habitats contain high quality food, which in return affects the expression of carotenoid-based plumage. It therefore assumes that, at the population level, the link between habitat structure and food composition is consistent and more relevant than inter-individual differences in foraging ability or parental investment. In addition, it is assumed by default that food and habitat produce concordant effects on nestling coloration. In this work we evaluated habitat structure and prey composition in addition to several measures of parental investment. We investigated their relative effect on carotenoid-based plumage coloration (lightness, chroma and hue) of great tit Parus major nestlings. We found a low correlation between carotenoid-based coloration of nestlings and that of their parents. Nestling coloration, especially lightness and chroma, increased with the intake of more spiders. The time of breeding was positively correlated with lightness and chroma and negatively correlated with hue. Finally, the maturity of oak trees surrounding nest-boxes correlated negatively with lightness, and the size of all tree species surrounding nest-boxes correlated positively with hue of chick plumage. Our findings support the view that habitat structure and prey composition may produce divergent effects on feather pigmentation, and that prey proportions and variables related to parental investment should be assessed when considering carotenoid-based coloration of chicks. © 2014 The Linnean Society of London.

Pagani-Nunez E.,Evolutionary Ecology Associate Research Unit CSIC | Senar J.C.,Evolutionary Ecology Associate Research Unit CSIC
Ibis | Year: 2012

Yearling birds generally display duller colours than adults. This may be due to selection favouring birds with more intensely coloured plumage or to an increase in colour after the first complete moult. Most research to date on the topic has been carried out on species with structural plumage coloration or with carotenoid-based coloration that is produced by the unmodified deposition of pigments. However, no study has been carried out on species whose carotenoids are metabolically modified before deposition. In this study, we assess age-related changes in the carotenoid-based coloration of European Serins, a species that metabolically processes carotenoids before they can be deposited into feathers. Birds were captured over consecutive years and we carried out both cross-sectional and longitudinal analysis. Adults had significantly greater values of lightness and chroma than yearling birds. However, there were no changes in plumage colour when analysing the same individuals captured in subsequent seasons. Plumage lightness and chroma of adult males after moult were related to body mass, suggesting a role of body condition on plumage coloration. Our results suggest that changes in plumage coloration with age in European Serins are due to a selection process that favours more intensely coloured individuals. © 2011 The Authors. Ibis © 2011 British Ornithologists' Union.

Riyahi S.,Evolutionary Ecology Associate Research Unit CSIC | Sanchez-Delgado M.,Hospital Duran i Reynals | Calafell F.,University Pompeu Fabra | Monk D.,Hospital Duran i Reynals | Senar J.C.,Evolutionary Ecology Associate Research Unit CSIC
Epigenetics | Year: 2015

DNA methylation is one of the main epigenetic mechanisms that can regulate gene expression and is an important means for creating phenotypic variation. In the present study, we performed methylation profiling of 2 candidate genes for personality traits, namely DRD4 and SERT, in the great tit Parus major to ascertain whether personality traits and behavior within different habitats have evolved with the aid of epigenetic variation. We applied bisulphite PCR and strand-specific sequencing to determine the methylation profile of the CpG dinucleotides in the DRD4 and SERT promoters and also in the CpG island overlapping DRD4 exon 3. Furthermore, we performed pyrosequencing to quantify the total methylation levels at each CpG location. Our results indicated that methylation was ∼1–4% higher in urban than in forest birds, for all loci and tissues analyzed, suggesting that this epigenetic modification is influenced by environmental conditions. Screening of genomic DNA sequence revealed that the SERT promoter is CpG poor region. The methylation at a single CpG dinucleotide located 288 bp from the transcription start site was related to exploration score in urban birds. In addition, the genotypes of the SERT polymorphism SNP234 located within the minimal promoter were significantly correlated with novelty seeking behavior in captivity, with the allele increasing this behavior being more frequent in urban birds. As a conclusion, it seems that both genetic and methylation variability of the SERT gene have an important role in shaping personality traits in great tits, whereas genetic and methylation variation at the DRD4 gene is not strongly involved in behavior and personality traits. © 2015, Taylor and Francis Group, LLC.

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