Polioptilidae (2 Viewers)

[ntbirdman]

Species delimitation and biogeography of the gnatcatchers and gnatwrens (Aves: Polioptilidae). Brian Tilston Smith, Robert W. Bryson Jr., William M. Mauck III, Jaime Chaves, Mark B. Robbins, Alexandre Aleixo, John Klicka. Biorxiv: https://www.biorxiv.org/content/early/2018/02/26/271494

Abstract:The New World avian family Polioptilidae (gnatcatchers and gnatwrens) is distributed from Argentina to Canada and includes 15 species and more than 60 subspecies. No study to date has evaluated phylogenetic relationships within this family and the historical pattern of diversification within the group remains unknown. Moreover, species limits, particularly in widespread taxa that show geographic variation, remain unclear. In this study, we delimited species and estimated phylogenetic relationships using multilocus data for the entire family. We then used the inferred diversity along with alternative taxonomic classification schemes to evaluate how lumping and splitting of both taxa and geographical areas influenced biogeographic inference. Species-tree analyses grouped Polioptilidae into four main clades: Microbates, Ramphocaenus, a Polioptila guianensis complex, and the remaining members of Polioptila. Ramphocaenus melanurus was sister to the clade containing M. cinereiventris and M. collaris, which formed a clade sister to all species within Polioptila. Polioptila was composed of two clades, the first of which included the P. guianensis complex; the other contained all remaining species in the genus. Using multispecies coalescent modeling, we inferred a more than 3-fold increase in species diversity, of which 87% represent currently recognized species or subspecies. Much of this diversity corresponded to subspecies that occur in the Neotropics. We identified three polyphyletic species, and delimited 4-6 previously undescribed candidate taxa. Probabilistic modeling of geographic ranges on the species tree indicated that the family likely had an ancestral origin in South America, with all three genera independently colonizing North America. Support for this hypothesis, however, was sensitive to the taxonomic classification scheme used and the number of geographical areas allowed. Our study proposes the first phylogenetic hypothesis for Polioptilidae and provides genealogical support for the reclassification of species limits. Species limits and the resolution of geographical areas that taxa inhabit influence the inferred spatial diversification history.

 

[pbjosh]

This provides some timely insight to the P guianensis group as SACC is currently considering a proposal on this group: http://www.museum.lsu.edu/~Remsen/SACCprop751.htm

Some great and interesting stuff in there, particularly that P albiloris in the N Yucatan is embedded in the P plumbea complex instead of in P albiloris.

The number of proposed species is a bit boggling, I will need to read this in more detail and am curious to hear others' opinions.

 

[Jim LeNomenclatoriste]

TiF Update Marsh 15

Gnatcatchers: The Gnatcatchers have been restructured based on Smith et al. (2018). The Yucatan Gnatcatcher, Polioptila albiventris, has been split from the White-lored Gnatcatcher, Polioptila albiloris. The Tropical Gnatcatcher, Polioptila plumbea has been split into:

Eastern Tropical Gnatcatcher, Polioptila atricapilla.
Northeastern Tropical Gnatcatcher, Polioptila plumbea.
Western Tropical Gnatcatcher, Polioptila parvirostris.
Maranon Gnatcatcher Polioptila maior.
Northwestern Tropical Gnatcatcher Polioptila plumbiceps, including innotata, plumbiceps, and anteocularis.
White-browed Gnatcatcher, Polioptila bilineata, including daguae, bilineata, cinericia, brodkorbi, and superciliaris.
A more complete description may be found in
[, Polioptilidae, 3.04] [sic]

 

[Peter Kovalik]

Carina Carneiro de Melo Moura Helder F. P. de Araujo Alexandre Aleixo Michael Wink Alexandre M. Fernandes. The role of landscape change and paleoclimatic events in shaping the evolutionary history of the Polioptila Gnatcatchers (Passeriformes, Polioptilidae) with emphasis on species associated with open habitats. Journal of Avian Biology, First published: 18 April 2018.

Abstract:

We conducted a large‐scale phylogenetic and biogeographical inference of the Poliptila Gnatcatchers and investigated the evolutionary history of two closely related neotropical bird species linked to open habitats, Polioptila dumicola and P. plumbea. A Bayesian inference was employed based on the NADH subunit 2 gene to reconstruct the phylogenetic relationship of the Gnatcatchers, and ancestral area reconstructions were estimated using BioGeoBEARS. For the phylogeographic analysis, we analyzed two mitochondrial genes, Cytochrome b and ND2, of 102 individuals from P. dumicola and P. plumbea distributed throughout the complete range of both species. To reconstruct the dates related to the splitting events, we included a subset of sequences from the nuclear gene beta‐fibrinogen intron‐7. A striking result was the recovery of the sister relationship between the lineages of P. dumicola/plumbea and the paraphyly among the subspecies of P. plumbea: the first group was formed by P. dumicola, P. p. plumbea, P. p. parvirostris, P. p. atricapilla and P. lactea, occurring mainly on the Brazilian shield; while the second group consisted of lineages from north of the Amazon, west of the Andes, and Central America, and included P. maior, P. p. cinericia, P. p. bilineata and P. p. innotata. Significant phylogeographic structure was evident within lineages attributed to P. plumbea, with high levels of differentiation in the well‐defined clades according to all phylogenetic analyses. Our biogeographic analyses support distinct evolutionary histories related to founder events and vicariance, occurring during the late Pliocene and early Pleistocene. Several dispersal episodes between North / Central America and South America led to the establishment of populations which became differentiated due to landscape changes, such as the establishment of riverine barriers, the uplift of the Andes and the formation of the Panama Isthmus.

 

[Peter Kovalik]

Ramphocaenus melanurus

Species delimitation and biogeography of the gnatcatchers and gnatwrens (Aves: Polioptilidae). Brian Tilston Smith, Robert W. Bryson Jr., William M. Mauck III, Jaime Chaves, Mark B. Robbins, Alexandre Aleixo, John Klicka. Biorxiv: https://www.biorxiv.org/content/early/2018/02/26/271494

Proposal (790) to SACC

Change species limits within Ramphocaenus melanurus

 

[Peter Kovalik]

Ramphocaenus sticturus

IOC Updates Diary Dec 22

Accept Chattering Gnatwren

 

[Peter Kovalik]

Ramphocaenus sticturus

Proposal (790) to SACC

Change species limits within Ramphocaenus melanurus

Treat Ramphocaenus sticturus as a separate species from Ramphocaenus melanurus (Proposal 790A; PASSED 18 April 2019) Needs proposal on English names before implementation

Proposal 790B. Treat rufiventris subspecies group as a separate species from Ramphocaenus melanurus DID NOT PASS

 

[Peter Kovalik]

Ramphocaenus

Proposal (821) to SACC

English names within Ramphocaenus melanurus complex

 

[Peter Kovalik]

Polioptila albivenris

IOC Updates Diary June 3

Accept Yucatan Gnatcatcher

 

[Peter Kovalik]

Proposal (821) to SACC

English names within Ramphocaenus melanurus complex

PASSED (30 Jan 2020)

 

[Jacana]

Vandergast, A.G., Kus, B.E., Wood, D.A., Milano, E.R. and Preston, K.L. (2022), Subspecies differentiation and range-wide genetic structure are driven by climate in the California gnatcatcher, a flagship species for coastal sage scrub conservation. Evol Appl. Accepted Author Manuscript. https://doi.org/10.1111/eva.13429

Understanding genetic structure and diversity within species can uncover associations with environmental and geographic attributes that highlight adaptive potential and inform conservation and management. The California gnatcatcher, Polioptila californica, is a small songbird found in desert and coastal scrub habitats from the southern end of Baja California Sur to Ventura County, California. Lack of congruence among morphological subspecies hypotheses and lack of measurable genetic structure found in a few genetic markers led to questions about the validity of subspecies within P. californica and the listing status of the coastal California gnatcatcher, P. c. californica. As a U.S. federally threatened subspecies, P. c. californica is recognized as a flagship for coastal sage scrub conservation throughout southern California. We used restriction site-associated DNA sequencing to develop a genomic dataset for the California gnatcatcher. We sampled throughout the species’ range, examined genetic structure, gene-environment associations, and demographic history, and tested for concordance between genetic structure and morphological subspecies groups. Our data support two distinct genetic groups with evidence of restricted movement and gene flow near the U.S.- Mexico international border. We found that climate-associated outlier loci were more strongly differentiated than climate neutral loci, suggesting that local climate adaptation may have helped to drive differentiation after Holocene range expansions. Patterns of habitat loss and fragmentation are also concordant with genetic substructure throughout the southern California portion of the range. Finally, our genetic data supported the morphologically defined P. c. californica as a distinct group, but there was little evidence of genetic differentiation among other previously hypothesized subspecies in Baja California. Our data suggest that retaining and restoring connectivity, and protecting populations, particularly at the northern range edge, could help preserve existing adaptive potential to allow for future range expansion and long-term persistence of the California gnatcatcher.