| long-term trends in first arrival and first egg laying dates of some migrant and resident bird species in northern italy. | climate change is affecting the phenology of seasonal events in europe and the northern hemisphere, as shown by several studies of birds' timing of migration and reproduction. here, we analyse the long-term (1982-2006) trends of first arrival dates of four long-distance migratory birds [swift (apus apus), nightingale (luscinia megarhynchos), barn swallow (hirundo rustica), and house martin (delichon urbicum)] and first egg laying dates of two migrant (swift, barn swallow) and two resident specie ... | 2007 | 17375338 |
| interspecies differences in mixed function oxidase activity in birds: relationship between feeding habits, detoxication activities and organochlorine accumulation. | the relationship between feeding habits and interspecies differences in the detoxication ability of the mixed function oxidase (mfo) system was investigated in birds. the role of mfo (particularly aldrin epoxidase activity) in the detoxication/bioaccumulation of organochlorines was also investigated. euriphagic (yellow-legged herring gull (larus cachinnans), black-headed gull (larus ridibundus), jackdaw (corvus monedula), magpie (pica pica) and stenophagic (cormorant (phalacrocorax carbo), coot ... | 1995 | 15091496 |
| north african hybrid sparrows (passer domesticus, p. hispaniolensis) back from oblivion - ecological segregation and asymmetric mitochondrial introgression between parental species. | a stabilized hybrid form of the house sparrow (passer domesticus) and the spanish sparrow (p. hispaniolensis) is known as passer italiae from the italian peninsula and a few mediterranean islands. the growing attention for the italian hybrid sparrow and increasing knowledge on its biology and genetic constitution greatly contrast the complete lack of knowledge of the long-known phenotypical hybrid sparrow populations from north africa. our study provides new data on the breeding biology and vari ... | 2016 | 27551376 |
| strong selection on male plumage in a hybrid zone between a hybrid bird species and one of its parents. | homoploid hybrid speciation (hhs) requires reproductive barriers between hybrid and parent species, despite incomplete reproductive isolation (ri) between the parents. novel secondary sexual trait values in hybrids may cause prezygotic isolation from both parents, whereas signals inherited by the hybrid from one parent species may cause prezygotic isolation with the other. here we investigate whether differences in male plumage function as a premating barrier between the hybrid italian sparrow a ... | 2015 | 25940369 |
| evidence for mito-nuclear and sex-linked reproductive barriers between the hybrid italian sparrow and its parent species. | studies of reproductive isolation between homoploid hybrid species and their parent species have rarely been carried out. here we investigate reproductive barriers between a recently recognized hybrid bird species, the italian sparrow passer italiae and its parent species, the house sparrow p. domesticus and spanish sparrow p. hispaniolensis. reproductive barriers can be difficult to study in hybrid species due to lack of geographical contact between taxa. however, the italian sparrow lives para ... | 2014 | 24415954 |
| local adaptation within a hybrid species. | ecological divergence among populations may be strongly influenced by their genetic background. for instance, genetic admixture through introgressive hybridization or hybrid speciation is likely to affect the genetic variation and evolvability of phenotypic traits. we studied geographic variation in two beak dimensions and three other phenotypic traits of the italian sparrow (passer italiae), a young hybrid species formed through interbreeding between house sparrows (p. domesticus) and spanish s ... | 2013 | 23695379 |
| hybrid speciation in sparrows i: phenotypic intermediacy, genetic admixture and barriers to gene flow. | homoploid hybrid speciation is thought to require unusual circumstances to yield reproductive isolation from the parental species, and few examples are known from nature. here, we present genetic evidence for this mode of speciation in birds. using bayesian assignment analyses of 751 individuals genotyped for 14 unlinked, nuclear microsatellite loci, we show that the phenotypically intermediate italian sparrow (passer italiae) does not form a cluster of its own, but instead exhibits clear admixt ... | 2011 | 21771138 |
| hybrid speciation in sparrows ii: a role for sex chromosomes? | homoploid hybrid speciation in animals is poorly understood, mainly because of the scarcity of well-documented cases. here, we present the results of a multilocus sequence analysis on the house sparrow (passer domesticus), spanish sparrow (p. hispaniolensis) and their proposed hybrid descendant, the italian sparrow (p. italiae). the italian sparrow is shown to be genetically intermediate between the house sparrow and spanish sparrow, exhibiting genealogical discordance and a mosaic pattern of al ... | 2011 | 21762432 |
| [a new species of the italian tick fauna. ii. ixodes arboricola schulze and schlottke, 1929]. | the bird-tick ixodes (pholeoxiodes) arboricola schulze and schlottke, 1929, is reported for the first time in italy with larvae and nymphs parasitizing passer domesticus italiae (vieillot) and phoenicurus ph. phoenicurus l. variation, natural bird hosts and presumed distribution also in italian alps and apennines are discussed. | 1991 | 1844509 |
| rapid polygenic response to secondary contact in a hybrid species. | secondary contact between closely related species can have genetic consequences. competition for essential resources may lead to divergence in heritable traits that reduces interspecific competition leading to increased rate of genetic divergence. conversely, hybridization and backcrossing can lead to genetic convergence. here, we study a population of a hybrid species, the italian sparrow (passer italiae), before and after it came into secondary contact with one of its parent species, the spani ... | 2017 | 28446700 |
| hybrid speciation through sorting of parental incompatibilities in italian sparrows. | speciation by hybridization is emerging as a significant contributor to biological diversification. yet, little is known about the relative contributions of (i) evolutionary novelty and (ii) sorting of pre-existing parental incompatibilities to the build-up of reproductive isolation under this mode of speciation. few studies have addressed empirically whether hybrid animal taxa are intrinsically isolated from their parents, and no study has so far investigated by which of the two aforementioned ... | 2014 | 25208037 |
| the genomic mosaicism of hybrid speciation. | hybridization is widespread in nature and, in some instances, can result in the formation of a new hybrid species. we investigate the genetic foundation of this poorly understood process through whole-genome analysis of the hybrid italian sparrow and its progenitors. we find overall balanced yet heterogeneous levels of contribution from each parent species throughout the hybrid genome and identify areas of novel divergence in the hybrid species exhibiting signals consistent with balancing select ... | 2017 | 28630911 |
| hybrid speciation in birds: allopatry more important than ecology? | hybrid speciation was once thought to be rare in animals, but over the past decade, improved molecular analysis techniques and increased research attention have allowed scientists to uncover many examples. in this issue, two papers (elgvin et al. 2011; hermansen et al. 2011) present compelling evidence for the hybrid origin of the italian sparrow based on nuclear and mitochondrial dna sequences, microsatellites, and plumage coloration. these studies point to an important role for geographic isol ... | 2011 | 21902744 |
| [on the presence and significance of the thymus ii in passer italiae]. | | 1961 | 13770290 |
| analysis of 11 trace elements in flight feathers of italian sparrows in southern italy: a study of bioaccumulation through age classes, variability in three years of sampling, and relations with body condition. | trace elements have been acknowledged as one of the subtlest environmental hazards in all compartments of the total environment. enhanced by activities in the anthroposphere, they accumulate in the atmosphere, lithosphere, and hydrosphere. eventually, trace elements can bioaccumulate or biomagnifiy in the biosphere, with harmful effects on animals occupying higher trophic levels, including humans. accordingly, there is great interest in assessing and monitoring trace element concentrations in th ... | 2019 | 30321723 |
| genetic admixture despite ecological segregation in a north african sparrow hybrid zone (aves, passeriformes, passer domesticus × passer hispaniolensis). | under different environmental conditions, hybridization between the same species might result in different patterns of genetic admixture. particularly, species pairs with large distribution ranges and long evolutionary history may have experienced several independent hybridization events over time in different zones of overlap. in birds, the diverse hybrid populations of the house sparrow (passer domesticus) and the spanish sparrow (passer hispaniolensis) provide a striking example. throughout t ... | 2019 | 31788209 |
| exploring the hybrid speciation continuum in birds. | hybridization is increasingly recognized as a creative evolutionary force contributing to adaptation and speciation. homoploid hybrid speciation-the process in which hybridization results in a stable, fertile, and reproductively isolated hybrid lineage where there is no change in ploidy-has been documented in several taxa. hybridization can directly contribute to reproductive isolation or reinforce it at a later stage. alternatively, hybridization might not be related to the evolution of reprodu ... | 2018 | 30619602 |
| genomic contingencies and the potential for local adaptation in a hybrid species. | hybridization is increasingly recognized as a potent evolutionary force. although additive genetic variation and novel combinations of parental genes theoretically increase the potential for hybrid species to adapt, few empirical studies have investigated the adaptive potential within a hybrid species. here, we address whether genomic contingencies, adaptation to climate, or diet best explain divergence in beak morphology using genomically diverged island populations of the homoploid hybrid ital ... | 2018 | 29897805 |
| variation and constraints in hybrid genome formation. | hybridization is an important source of variation; it transfers adaptive genetic variation across species boundaries and generates new species. yet, the limits to viable hybrid genome formation are poorly understood. here we investigated to what extent hybrid genomes are free to evolve by sequencing the genomes of four island populations of the homoploid hybrid italian sparrow passer italiae. we report that a variety of novel and fully functional hybrid genomic combinations are likely to have ar ... | 2018 | 29335572 |