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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.

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.

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 - Donana 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.

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 | 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.

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