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Pachyramphus (1 Viewer)

Peter Kovalik

Well-known member
Slovakia
Musher & Cracraft. Phylogenomics and species delimitation of a complex radiation of Neotropical suboscine birds (Pachyramphus). Molecular Phylogenetics and Evolution, Accepted Manuscript. Available online 22 September 2017.

Abstract

Phylogeographic studies within the Neotropics continue to uncover hidden diversity, the extent of which remains poorly known. In birds, molecular studies are producing evidence that species-level diversity is substantially underestimated. Many avian taxa comprise large complexes of subspecies that often represent species-level taxa by various criteria. One such group of Neotropical suboscine birds, the becards (Pachyramphus), ranges from Argentina through northern Mexico. Their taxonomic limits have been complex and controversial as the genus has bounced around a number of suboscine families. Additionally, the phylogenetic relationships within Pachyramphus are unresolved due to insufficient sampling of taxa and populations across species’ ranges. We used target capture of ultraconserved elements for 62 individuals representing 42 taxa, and sequenced two mitochondrial genes and two nuclear introns covering 265 individuals of 51 taxa, including all recognized species, resulting in the most densely and completely sampled phylogenetic hypothesis for Pachyramphus to date. We delimited species using a traditional taxonomic approach and then tested them under a Bayesian multi-species coalescent framework. In doing so, we provide evidence for multiple young, previously undetected evolutionary lineages within Pachyramphus. Deep, well-supported branches and a high number of intraspecific lineages across the tree suggest that at least 50% of species diversity may be unrecognized.
 
Lukas J. Musher, Peter J. Galante, Gregory Thom, Jerry W. Huntley & Mary E. Blair. Shifting ecosystem connectivity during the Pleistocene drove diversification and gene‐flow in a species complex of Neotropical birds (Tityridae: Pachyramphus). Journal of Biogeography. First published:25 April 2020 https://doi.org/10.1111/jbi.13862

Abstract:

Aim
We aim to test the biogeographic drivers of diversification and gene‐flow at the Isthmus of Panama using a species complex of suboscine birds as a case study. We specifically evaluate whether diversification in these birds is better explained by continuous parapatry or a Refuge Model of periodic isolation and gene‐flow due glacial cycling.

Location
The Isthmus of Panama (Neotropics).

Taxon
Pachyramphus aglaiae and Pachyramphus homochrous (Aves: Tityridae).

Methods
We develop an approach to distinguish among the two biogeographic hypotheses—parapatric ecological speciation versus climatically mediated speciation—by making explicit predictions for demographic history, niche evolution and change in geographic connectivity over time. We sequenced genome‐wide markers (ultraconserved elements) to estimate the evolutionary and demographic history of this group. We applied both phylogenomic network analyses and demographic modelling using a supervised machine learning approach. These genetic analyses were combined with a novel distribution modelling method that estimates the probability of interspecies contact as a function of climatic conditions through time.

Results
We found that both spatial and genetic analyses revealed concordant results. All speciation events occurred during the Pleistocene and were characterized by non‐continuous gene‐flow, supporting a scenario of climate‐mediated diversification. Spatial connectivity was highest at present, consistent with our best demographic model of secondary contact.

Main conclusions
This study exemplifies a mechanism by which speciation, dispersal and introgression unfold in an important region for Neotropical diversification—the Isthmus of Panama—where periods of both isolation and introgression probably drive diversification. Overall, our results are consistent with the Refuge Model of biotic diversification, but suggest that introgression may be a crucial yet underappreciated component of this classic paradigm.
 
I do prefer the suggested names that Lane came up with over those of the proposal. Greater and Lesser Pied Becard are I think useful plus more aesthetically pleasing.
Agreed, it's an elegant solution.

Point of order for SACC business. Would they require a separate (sub)proposal on these new names, should the author's suggestions fail the vote. Or would they just accept Lane's idea if they all say so in the comments?
 
Agreed, it's an elegant solution.

Point of order for SACC business. Would they require a separate (sub)proposal on these new names, should the author's suggestions fail the vote. Or would they just accept Lane's idea if they all say so in the comments?
If everyone or at least almost everyone accepts it then I think it will just pass without a subproposal...I could have sworn that has happened in the past.

Sometimes they do a second proposal (like with Black-throated Trogon recently), but that is usually in cases where there is clearly not a single option everyone likes.
 
I disagree. The names imply that they are sisters, which they’re not.
I don't think so. If the name was Lesser Pied-Becard and Greater Pied-Becard then it would imply a sister relationship, but without the hyphens the names become purely descriptive.

I think we worry too much about inferring phylogenetic relationships from vernacular names- but I suppose this is a topic that the forum has discussed to death several times before.
 
As neither "Black-and-white" nor "Pied" describe the (mostly grey) males well (let alone the females!), completely new names are better.
(I never liked the name Black-and-white Becard, which fits Glossy-backed much better).
 
I don't think so. If the name was Lesser Pied-Becard and Greater Pied-Becard then it would imply a sister relationship, but without the hyphens the names become purely descriptive.

I think we worry too much about inferring phylogenetic relationships from vernacular names- but I suppose this is a topic that the forum has discussed to death several times before.
Since IOC don't do hyphens, that will certainly be a problem. I can discuss it forever ;-)
 
Since IOC don't do hyphens, that will certainly be a problem. I can discuss it forever ;-)
If people can survive with Lesser and Great Spotted Woodpeckers being in different genera, I think Lesser and Greater Pied Becards won't be too much of an issue.

And lets not even bring up the terms Tanager or Flycatcher...
 
I think Dan’s idea for names is a great improvement on Broad-banded and Slender-billed, which neither tell you anything useful to ID the birds not reference what they used to be called.

I am fine with two non-sister Pied Becards.

Or leave the more widespread species Black-and-white and call the other Tumbes or Western or something.

So many times useful or established names get shelved for what are ultimately kind of small/petty reasons and we end up with things like Thick-billed Longspur - Prairie or Shortgrass would have been far better and more helpful names even if they are not uniquely identifying. I can guarantee you no one will ever ID that Longspur or either Becard by bill or band dimensions.
 
I think Dan’s idea for names is a great improvement on Broad-banded and Slender-billed, which neither tell you anything useful to ID the birds not reference what they used to be called.

I am fine with two non-sister Pied Becards.

Or leave the more widespread species Black-and-white and call the other Tumbes or Western or something.

So many times useful or established names get shelved for what are ultimately kind of small/petty reasons and we end up with things like Thick-billed Longspur - Prairie or Shortgrass would have been far better and more helpful names even if they are not uniquely identifying. I can guarantee you no one will ever ID that Longspur or either Becard by bill or band dimensions.
To the contrary, Thick-billed Longspur is noticeably bigger-billed in the field, and that is a useful ID feature in basic plumage. (I've used it in California.)

Though to get back to the becards, love Dan Lane's proposed names.
 

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