Jim LeNomenclatoriste
Je suis un mignon petit Traquet rubicole
-
Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.
Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
Corvidae (3 Viewers)
- Thread starter Peter Kovalik
- Start date
Kirk Roth
Rarely to be taken seriously
Its even more complicated than that. The western hesperis subspecies has a deeper voice than the eastern subspecies, so which of those is Nat Geo comparing them to? And the south Florida crows reported to be very different vocally in both tone and repertoire.
If you're interested, here is some investigation from someone who has dove deeper into the vocalizations than Nat Geo!
Mysticete
Well-known member
If the blackbirds were hardwired with there vocalizations AND those differences in song prevented/reduced interbreeding, then yeah, the different blackbirds should be split as different species.
But of course, as far as I know (at least in Europe), none of those is true.
But of course, as far as I know (at least in Europe), none of those is true.
Jacana
Will Jones
I've not read the paper yet, but there is a valid argument backed up by several studies that show that species boundaries can breakdown in anthropogenic habitats. There's an old study on Paradise Flycatchers that showed this IIRC and some cichlid examples too. It's a hypothesis worth exploring, however I'm not sure that the hypothesis alone is enough to overturn the lump.
Peter Kovalik
Well-known member
Dirk Metzler, Ulrich Knief, Joshua V.Penalba, and Jochen B. W. Wolf. 2021. Assortative mating and epistatic mating-trait architecture induce complex movement of the crow hybrid zone. Evolution. First published: 25 October 2021.
https://doi.org/10.1111/evo.14386
Abstract
Hybrid zones provide a window into the evolutionary processes governing species divergence. Yet, the contribution of mate choice to the temporal and spatial stability of hybrid zones remains poorly explored. Here, we investigate the effects of assortative mating on hybrid zone dynamics by means of a mathematical model parameterized with phenotype and genotype data from the hybrid zone between all-black carrion and grey-coated hooded crows. In the best-fit model, narrow clines of the two mating-trait loci were maintained by a moderate degree of assortative mating inducing pre- and post-zygotic isolation via positive frequency-dependent selection. Epistasis between the two loci induced hybrid-zone movement in favor of alleles conveying dark plumage followed by a shift in the opposite direction favouring grey-coated phenotypes 1,200 generations after secondary contact. Unlinked neutral loci diffused near-unimpeded across the zone. These results were generally robust to the choice of matching rule (self-referencing or parental imprinting) and effects of genetic drift. Overall, this study illustrates under which conditions assortative mating can maintain steep clines in mating-trait loci without generalizing to genome-wide reproductive isolation. It further emphasizes the importance of mating-trait architecture for spatio–temporal hybrid-zone dynamics.
https://doi.org/10.1111/evo.14386
Abstract
Hybrid zones provide a window into the evolutionary processes governing species divergence. Yet, the contribution of mate choice to the temporal and spatial stability of hybrid zones remains poorly explored. Here, we investigate the effects of assortative mating on hybrid zone dynamics by means of a mathematical model parameterized with phenotype and genotype data from the hybrid zone between all-black carrion and grey-coated hooded crows. In the best-fit model, narrow clines of the two mating-trait loci were maintained by a moderate degree of assortative mating inducing pre- and post-zygotic isolation via positive frequency-dependent selection. Epistasis between the two loci induced hybrid-zone movement in favor of alleles conveying dark plumage followed by a shift in the opposite direction favouring grey-coated phenotypes 1,200 generations after secondary contact. Unlinked neutral loci diffused near-unimpeded across the zone. These results were generally robust to the choice of matching rule (self-referencing or parental imprinting) and effects of genetic drift. Overall, this study illustrates under which conditions assortative mating can maintain steep clines in mating-trait loci without generalizing to genome-wide reproductive isolation. It further emphasizes the importance of mating-trait architecture for spatio–temporal hybrid-zone dynamics.
Jim LeNomenclatoriste
Je suis un mignon petit Traquet rubicole
Diversification and secondary contact in the magpie-jays (Calocitta) throughout the pacific lowlands of Mesoamerica
Luis A. Sánchez-González,Vicente J. Castillo-Chora,Enrique Arbeláez-Cortés,Adolfo G. Navarro-Sigüenza
Abstract
The Mesoamerican dry forests (MDF), rich in species and in endemic taxa, are distributed nearly continuously nearly continuously along the American Pacific slope from Mexico to Costa Rica; however, several of the bird species inhabiting the MDF show clear phenotypic differentiation recognized through the description of subspecies. There are two currently recognized species of magpie-jays of the genus Calocitta (Corvidae) distributed throughout the MDF: the monotypic black-throated magpie-jay (C. colliei) and the polytypic white-throated magpie-jay (C. formosa). These two species have sometimes been considered conspecific and have been reported to hybridize in sympatric areas, where birds with intermediate plumage characters are recorded. Using mitochondrial and nuclear DNA markers from individuals of the two species, we analyze the phylogeographic structure and the genetic diversity within Calocitta under an isolation with migration (IM) model. The results showed strong genetic structure, in which the two currently recognized species and some of the C. formosa subspecies grouped into four well-supported and reciprocally monophyletic clades. IM analyses suggested divergence dates for the split between C. colliei and C. formosa that were congruent with geological factors, as well as with the deep divergence of the three lineages within C. formosa. These factors likely led to a dynamic demographic history in all lineages. We also found strongly limited gene flow, null or near null migration values, and large genetic fixation and genetic distance values. We suggest that the strong genetic differentiation between lineages is the result of allopatric differentiation with later secondary contact, further supporting a highly dynamic biotic history in MDF.
Luis A. Sánchez-González,Vicente J. Castillo-Chora,Enrique Arbeláez-Cortés,Adolfo G. Navarro-Sigüenza
Abstract
The Mesoamerican dry forests (MDF), rich in species and in endemic taxa, are distributed nearly continuously nearly continuously along the American Pacific slope from Mexico to Costa Rica; however, several of the bird species inhabiting the MDF show clear phenotypic differentiation recognized through the description of subspecies. There are two currently recognized species of magpie-jays of the genus Calocitta (Corvidae) distributed throughout the MDF: the monotypic black-throated magpie-jay (C. colliei) and the polytypic white-throated magpie-jay (C. formosa). These two species have sometimes been considered conspecific and have been reported to hybridize in sympatric areas, where birds with intermediate plumage characters are recorded. Using mitochondrial and nuclear DNA markers from individuals of the two species, we analyze the phylogeographic structure and the genetic diversity within Calocitta under an isolation with migration (IM) model. The results showed strong genetic structure, in which the two currently recognized species and some of the C. formosa subspecies grouped into four well-supported and reciprocally monophyletic clades. IM analyses suggested divergence dates for the split between C. colliei and C. formosa that were congruent with geological factors, as well as with the deep divergence of the three lineages within C. formosa. These factors likely led to a dynamic demographic history in all lineages. We also found strongly limited gene flow, null or near null migration values, and large genetic fixation and genetic distance values. We suggest that the strong genetic differentiation between lineages is the result of allopatric differentiation with later secondary contact, further supporting a highly dynamic biotic history in MDF.
albertonykus
Well-known member
Garcia-Porta, J., D. Sol, M. Pennell, F. Sayol, A. Kaliontzopoulou, and C.A. Botero (2022)
Niche expansion and adaptive divergence in the global radiation of crows and ravens
Nature Communications 13: 2086
doi: 10.1038/s41467-022-29707-5
The processes that allow some lineages to diversify rapidly at a global scale remain poorly understood. Although earlier studies emphasized the importance of dispersal, global expansions expose populations to novel environments and may also require adaptation and diversification across new niches. In this study, we investigated the contributions of these processes to the global radiation of crows and ravens (genus Corvus). Combining a new phylogeny with comprehensive phenotypic and climatic data, we show that Corvus experienced a massive expansion of the climatic niche that was coupled with a substantial increase in the rates of species and phenotypic diversification. The initiation of these processes coincided with the evolution of traits that promoted dispersal and niche expansion. Our findings suggest that rapid global radiations may be better understood as processes in which high dispersal abilities synergise with traits that, like cognition, facilitate persistence in new environments.
Niche expansion and adaptive divergence in the global radiation of crows and ravens
Nature Communications 13: 2086
doi: 10.1038/s41467-022-29707-5
The processes that allow some lineages to diversify rapidly at a global scale remain poorly understood. Although earlier studies emphasized the importance of dispersal, global expansions expose populations to novel environments and may also require adaptation and diversification across new niches. In this study, we investigated the contributions of these processes to the global radiation of crows and ravens (genus Corvus). Combining a new phylogeny with comprehensive phenotypic and climatic data, we show that Corvus experienced a massive expansion of the climatic niche that was coupled with a substantial increase in the rates of species and phenotypic diversification. The initiation of these processes coincided with the evolution of traits that promoted dispersal and niche expansion. Our findings suggest that rapid global radiations may be better understood as processes in which high dispersal abilities synergise with traits that, like cognition, facilitate persistence in new environments.
Peter Kovalik
Well-known member
Rosa, Gabriel L. M., and dos Anjos, Luiz (2022) Out of the blue: geographic variation and divergence between Azure Jays (Cyanocorax caeruleus) from two ecologically distinct ranges. Emu, Published online 22 June 2022
https://doi.org/10.1080/01584197.2022.2078218
ABSTRACT
Underlying biological processes can often shape phenotypic variation. Although subtle, the variation in plumage colour of the Azure Jay (Cyanocorax caeruleus) has long been suggested to be of phylogeographic importance, but this hypothesis was not tested. This species’ distribution in the Atlantic Forest biome of south-eastern Brazil is divided into two ecologically distinct portions by the Serra do Mar mountain line. The availability of Parana Pine (Araucaria angustifolia) seeds is essential for the survival of Azure Jays in the western range but not in the eastern range. Here we quantify Azure Jay geographic variation using three datasets, including vocalisations, morphology and plumage colour. All available data independently supported the hypothesis of divergence between east and west. Azure Jays in the western range tend to have: (1) larger body dimensions, (2) vocalisations with lower pitch and entropy, and (3) a greenish-blue plumage, than those in the eastern range. Based on the available data on this species’ ecology, life history and sociality, we discuss how features from the western range could indicate specialisation in habitat use. We discuss potential links between our results and the past of the Atlantic Forest and the implications for this species conservation in a highly threatened habitat. Finally, we highlight the pressing need for demographic and molecular evidence to make data-oriented and effective decisions for this species conservation.
https://doi.org/10.1080/01584197.2022.2078218
ABSTRACT
Underlying biological processes can often shape phenotypic variation. Although subtle, the variation in plumage colour of the Azure Jay (Cyanocorax caeruleus) has long been suggested to be of phylogeographic importance, but this hypothesis was not tested. This species’ distribution in the Atlantic Forest biome of south-eastern Brazil is divided into two ecologically distinct portions by the Serra do Mar mountain line. The availability of Parana Pine (Araucaria angustifolia) seeds is essential for the survival of Azure Jays in the western range but not in the eastern range. Here we quantify Azure Jay geographic variation using three datasets, including vocalisations, morphology and plumage colour. All available data independently supported the hypothesis of divergence between east and west. Azure Jays in the western range tend to have: (1) larger body dimensions, (2) vocalisations with lower pitch and entropy, and (3) a greenish-blue plumage, than those in the eastern range. Based on the available data on this species’ ecology, life history and sociality, we discuss how features from the western range could indicate specialisation in habitat use. We discuss potential links between our results and the past of the Atlantic Forest and the implications for this species conservation in a highly threatened habitat. Finally, we highlight the pressing need for demographic and molecular evidence to make data-oriented and effective decisions for this species conservation.
pbjosh
missing the neotropics
I don't think this has been posted here yet:
Devon A DeRaad, John E McCormack, Nancy Chen, A Townsend Peterson, Robert G Moyle (2022) Combining Species Delimitation, Species Trees, and Tests for Gene Flow Clarifies Complex Speciation in Scrub-Jays. Systematic Biology, syac034, Combining Species Delimitation, Species Trees, and Tests for Gene Flow Clarifies Complex Speciation in Scrub-Jays Published: 15 June 2022
Abstract
Complex speciation, involving rapid divergence and multiple bouts of post-divergence gene flow, can obfuscate phylogenetic relationships and species limits. In North America, cases of complex speciation are common, due at least in part to the cyclical Pleistocene glacial history of the continent. Scrub-Jays in the genus Aphelocoma provide a useful case study in complex speciation because their range throughout North America is structured by phylogeographic barriers with multiple cases of secondary contact between divergent lineages. Here, we show that a comprehensive approach to genomic reconstruction of evolutionary history, i.e., synthesizing results from species delimitation, species tree reconstruction, demographic model testing, and tests for gene flow, is capable of clarifying evolutionary history despite complex speciation. We find concordant evidence across all statistical approaches for the distinctiveness of an endemic southern Mexico lineage (A. w. sumichrasti), culminating in support for the species status of this lineage under any commonly applied species concept. We also find novel genomic evidence for the species status of a Texas endemic lineage A. w. texana, for which equivocal species delimitation results were clarified by demographic modeling and spatially explicit models of gene flow. Finally, we find that complex signatures of both ancient and modern gene flow between the non-sister California Scrub-Jay (Aphelocoma californica) and Woodhouse’s Scrub-Jay (Aphelocoma woodhouseii) result in discordant gene trees throughout the species’ genomes despite clear support for their overall isolation and species status. In sum, we find that a multi-faceted approach to genomic analysis can increase our understanding of complex speciation histories, even in well-studied groups. Given the emerging recognition that complex speciation is relatively commonplace, the comprehensive framework that we demonstrate for interrogation of species limits and evolutionary history using genomic data can provide a necessary roadmap for disentangling the impacts of gene flow and incomplete lineage sorting (ILS) to better understand the systematics of other groups with similarly complex evolutionary histories. [Gene flow; genomics; introgression; phylogenomics; population genetics; species delimitation; species trees; systematics.]
Paper available HERE
Devon A DeRaad, John E McCormack, Nancy Chen, A Townsend Peterson, Robert G Moyle (2022) Combining Species Delimitation, Species Trees, and Tests for Gene Flow Clarifies Complex Speciation in Scrub-Jays. Systematic Biology, syac034, Combining Species Delimitation, Species Trees, and Tests for Gene Flow Clarifies Complex Speciation in Scrub-Jays Published: 15 June 2022
Abstract
Complex speciation, involving rapid divergence and multiple bouts of post-divergence gene flow, can obfuscate phylogenetic relationships and species limits. In North America, cases of complex speciation are common, due at least in part to the cyclical Pleistocene glacial history of the continent. Scrub-Jays in the genus Aphelocoma provide a useful case study in complex speciation because their range throughout North America is structured by phylogeographic barriers with multiple cases of secondary contact between divergent lineages. Here, we show that a comprehensive approach to genomic reconstruction of evolutionary history, i.e., synthesizing results from species delimitation, species tree reconstruction, demographic model testing, and tests for gene flow, is capable of clarifying evolutionary history despite complex speciation. We find concordant evidence across all statistical approaches for the distinctiveness of an endemic southern Mexico lineage (A. w. sumichrasti), culminating in support for the species status of this lineage under any commonly applied species concept. We also find novel genomic evidence for the species status of a Texas endemic lineage A. w. texana, for which equivocal species delimitation results were clarified by demographic modeling and spatially explicit models of gene flow. Finally, we find that complex signatures of both ancient and modern gene flow between the non-sister California Scrub-Jay (Aphelocoma californica) and Woodhouse’s Scrub-Jay (Aphelocoma woodhouseii) result in discordant gene trees throughout the species’ genomes despite clear support for their overall isolation and species status. In sum, we find that a multi-faceted approach to genomic analysis can increase our understanding of complex speciation histories, even in well-studied groups. Given the emerging recognition that complex speciation is relatively commonplace, the comprehensive framework that we demonstrate for interrogation of species limits and evolutionary history using genomic data can provide a necessary roadmap for disentangling the impacts of gene flow and incomplete lineage sorting (ILS) to better understand the systematics of other groups with similarly complex evolutionary histories. [Gene flow; genomics; introgression; phylogenomics; population genetics; species delimitation; species trees; systematics.]
Paper available HERE
Mysticete
Well-known member
Speaking of North American Jays...
Provides strong evidence and advocates for splitting Steller's Jay into two species, the coastal/interior Blue-fronted Jay (Cyanocitta stelleri) and the Rocky Mountain Long-crested Jay (Cyanocitta macrolopha).
They also suggest that the Central American populations might be worthy of a split (they are considered here as within Long-crested Jay, but that more information is needed before that determination can be made.
Provides strong evidence and advocates for splitting Steller's Jay into two species, the coastal/interior Blue-fronted Jay (Cyanocitta stelleri) and the Rocky Mountain Long-crested Jay (Cyanocitta macrolopha).
They also suggest that the Central American populations might be worthy of a split (they are considered here as within Long-crested Jay, but that more information is needed before that determination can be made.
andrew147
Well-known member
The subspecies diademata is usually included in the same group as macrolopha and has name priority. It is not sampled in Cicero et al. but they do mention it as part of the sspp group including macrolopha.
Morphology and biogeography would keep these sspp together, so, does anyone know the reason why Long-crested Jay is not Cyanocitta diademata?
Jim LeNomenclatoriste
Je suis un mignon petit Traquet rubicole
After the split of the species, how are the subspecies distributed?
I'm kind of bummed they didn't suggest Stellar Jay as the English name for one of the two daughter species, I mean they're pretty fantastic birds!
Mysticete
Well-known member
I believe there is a map in the paper showing this.
Mysticete
Well-known member
If we are going down the rabbit hole of common names, I prefer White-fronted Jay rather than Long-crested Jay, as I think it is a more useful name (again, there is a focus on priority as if priority mattered at all with common names), and contrasts nicely with Blue-fronted. While the Long-crested is...well...longer-crested, the difference feels a bit slight compared to other differences between the two forms.
Although I guess when the eventual split between Central American and northern Jays happen, we can save White-fronted for the northern population?
andrew147
Well-known member
They sample 7 out of 16 Steller's Jay taxa and the results align with the sspp groups of HBW/Clements.
The 7 taxa are grouped in a way which can be interpreted as:
1. Blue-fronted Jay Cyanocitta stelleri
incl. frontalis & carbonacea
2a. 'Northern' Long-crested Jay Cyanocitta [macrolopha] macrolopha
incl. annectens
2b. 'Central American' Long-crested Jay Cyanocitta [macrolopha] coronata
incl. ridgwayi
Following conventional wisdom, the unsampled sspp fit as follows:
(1) carlottae
(2a) diademata, phillipsi
(2b) purpurea, azteca, teotepecensis, restricta, lazula, suavis
The issue is the position of diademata because it has priority over macrolopha and would thus be the new species' name.
EDIT: I've just noticed that coronata also has priority over macrolopha (and diademata) - so the name Cyanocitta macrolopha is definitely wrong!
Should probably be:
1. Blue-fronted Jay Cyanocitta stelleri
2a. 'Northern' Long-crested Jay Cyanocitta [coronata] diademata
2b. 'Central American' Long-crested Jay Cyanocitta [coronata] coronata
Last edited:
Brian J Small
Well-known member
The linked paper has a number of illustrations. As the artist it would have been nice to have had an acknowledgment rather than a note saying they are from Birds of the World...
Brian
awiner
Well-known member
"Long-crested" Jay seems like a truly poor name for anything containing ssp.s ridgwayi and restricta - e.g, see this picture ML20917451 Steller's Jay Macaulay Library (I had a hard time believing this was really a Steller's Jay when I saw it in Guatemala)
Snapdragyn
Well-known member
Wow! That looks almost more like a Blue Jay with a black mask!
pbjosh
missing the neotropics
I just glanced through the paper and haven’t read in detail. However I do find it a bit disappointing (if typical) to read a paper that sampled 1080 individuals but nothing from Canada or Mexico and no nuclear genetics work? Might as well title it “phylogenetic analysis of all North American Stellar’s Jays” while they are at it…
