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(Not only) Thamnophilidae (3 Viewers)

Myrmoderus eowilsoni

BirdLife's Globally Threatened Bird Forums

The newly described taxon Cordillera Azul Antbird (Myrmoderus eowilsoni) is to be recognized as a species by BirdLife International

Posted on May 23, 2019 by Red List Team (BirdLife International)

Cordillera Azul Antbird (Myrmoderus eowilsoni) has been discovered in 2016 near Flor de Café in the western Cordillera Azul of the Peruvian Andes. Based on its vocalisation and on genetic and morphological analysis, the species was described as a new taxon in 2018 (Moncrieff et al. 2018).

Currently, Cordillera Azul Antbird is only known from the mountain ridge around the type locality between c. 1,300 and 1,700 m. However, it seems to be highly likely that the species has a wider distribution, encompassing further ridges in the Cordillera Azul and possibly also the Cordillera El Sira (Moncrieff et al. 2018). The authors assume that a large part of the population occurs in the Cordillera Azul National Park (Moncrieff et al. 2018).

The species inhabits tall, humid, montane forest with a dense vegetation cover in the understory. It seems to avoid secondary forest, edges and treefall gaps, but has been recorded in close proximity to large plantations (Moncrieff et al. 2018). Cordillera Azul Antbird keeps close to the ground and moves by walking or short, low flights (Moncrieff et al. 2018). The species is territorial; territories have been tentatively estimated at 0.25 km2 (Moncrieff et al. 2018).

Cordillera Azul Antbird was found to be fairly common in fragments of intact forest (Moncrieff et al. 2018). Based on the mean territory size of this species and the closely related Ferruginous-backed Antbird Mymoderus ferrugineus (Johnson et al. 2011), an estimate of habitat occupancy for Ferruginous-backed Antbird (Stouffer 2007) and the availability of suitable habitat, the authors produced a preliminary population estimate (Moncrieff et al. 2018): The Cordillera Azul National Park includes 1,940 km2 of forest between 1,300 and 1,700 m; hence the population of Cordillera Azul Antbird in the National Park may consist of 7,000-27,000 mature individuals. Including areas outside of the park in the right elevation throughout the entire cordillera increases the estimate to 9,000-34,000 mature individuals. Therefore, until more detailed information becomes available, we can place the population in the band 7,000-34,000 mature individuals.

The major threat to the forests around the type locality is the extensive, large-scale clear-cutting for conversion into coffee plantations. Until now however, the Cordillera Azul National Park protects large tracts of intact forest (Moncrieff et al. 2018).
Pyriglena leuconota, P. maura, P. similis


Calls distinguish species of Antbirds (Aves: Passeriformes: Thamnophilidae) in the genus Pyriglena



Populations in the genus Pyriglena Cabanis, 1847, commonly known as fire-eyes, are patchily distributed in central South America from the Pacific slope of the Andes to the Atlantic Forest of Brazil. Pyriglena populations are currently placed into 12 taxa, only five of which are not isolated from their neighbors by distance, a high mountain range, or a major river. In the Thamnophilidae, taxonomic decisions regarding such allopatric populations have primarily rested on differences in vocalizations, thought not to be learned and to play a key role in the speciation process. When we examined Pyriglena vocalizations in this context, the outcomes revealed substantial diversity in their calls, rather than their songs. They commonly delivered four different types of calls, unusual although not unprecedented in thamnophilids. Diversity in calls rather than songs underscores the need to consider all vocalizations in taxonomic studies. The outcomes support the continued recognition of the White-shouldered Fire-eye Pyriglena leucoptera (Vieillot) and Fringe-backed Fire-eye Pyriglena atra (Swainson) as distinct species, and indicate that, in addition, the currently constituted Pyriglena leuconota should be considered three species: the Western Fire-eye Pyriglena maura (Ménétries); the Tapajos Fire-eye Pyriglena similis Zimmer; and the East Amazonian Fire-eye Pyriglena leuconota (von Spix). We also identify taxonomic uncertainties regarding subspecies that require acquisition of additional data and further analysis.

IOC Updates Diary Feb 25

Accept split White-backed Fire-eye into three species with new and revised English names.
Sergio D.Bolívar-Leguizamón, Luís F.Silveira, Elizabeth P.Derryberry, Robb T.Brumfield, Gustavo A . bravo (2020). Phylogeographic and demographic history of the Variable Anthsrike (Thamnophilidae: Thamnophilus caerulescens), a widespread South American passerine distributed along multiple environmental gradients.
Molecular Phylogenetics and Evolution, Available online 5 April 2020. In Press.


Three well-defined genomic clusters within Thamnophilus caerulescens.

Intraspecific diversification of the species occurred during the Pleistocene.

Demographic modeling suggests a history of divergence and gene flow.

There is no evidence of dramatic events of population size change.

The most divergent and isolated cluster is the one in the northern Atlantic Forest.

The Neotropics show a wealth of distributional patterns shared by many co-distributed species. A distinctive pattern is the so-called “circum-Amazonian distribution,” which is observed in species that do not occur in Amazonia but rather along a belt of forested habitats spanning south and east of Amazonia, the Andean foothills, and often into the Venezuelan Coastal Range and the Tepuis. Although this pattern is widespread across animals and plants, its underlying biogeographic mechanisms remain poorly understood. The Variable Antshrike (Thamnophilus caerulescens) is a sexually dimorphic suboscine passerine that exhibits extreme plumage variation and occurs along the southern portion of the circum-Amazonian belt. We describe broad-scale phylogeographic patterns of T. caerulescens and assess its demographic history using DNA sequences from the mitochondrion and ultraconserved elements (UCEs). We identified three genomic clusters: a) northern Atlantic Forest; b) southeastern Cerrado and central-southern Atlantic Forest, and c) Chaco and Andes. Our results were consistent with Pleistocene divergence followed by gene flow, mainly between the latter two clusters. There were no genetic signatures of rapid population expansions or bottlenecks. The population from the northern Atlantic Forest was the most genetically divergent group within the species. The demographic history of T. caerulescens was probably affected by series of humid and dry periods throughout the Quaternary that generated subtle population expansions and contractions allowing the intermittent connection of habitats along the circum-Amazonian belt. Recognizing the dynamic history of climate-mediated forest expansions, contractions, and connections during the South American Pleistocene is central toward a mechanistic understanding of circum-Amazonian distributions.


Manuelita Sotelo-Muñoz, Marcos Maldonado-Coelho, Maria Svensson-Coelho, Sidnei S. dos Santos, Cristina Y. Miyaki. Vicariance, dispersal, extinction and hybridization underlie the evolutionary history of Atlantic Forest fire-eye antbirds (Aves: Thamnophilidae). Molecular Phylogenetics and Evolution. In Press, Journal Pre-proof, Available online 10 April 2020 https://doi.org/10.1016/j.ympev.2020.106820


In order to gain insights into the biogeographic processes underlying biotic diversification in the Atlantic Forest (AF), we used a multi-locus approach to examine the evolutionary history of the White-shouldered Fire-eye (Pyriglena leucoptera) and the Fringe-backed Fire-eye (Pyriglena atra), two parapatric sister species endemic to the AF. We sequenced one mitochondrial, three Z chromosome-linked and three anonymous markers of 556 individuals from 66 localities. We recovered four lineages throughout the AF: P. atra and three populations within P. leucoptera. All populations diverged during the late Pleistocene and presented varying levels of admixture. One Z-linked locus showed the highest level of differentiation between the two species. On the other hand, a mitochondrial haplotype was shared extensively between them. Our data supported vicariance driving speciation along with extinction and dispersal as processes underlying intraspecific diversification. Furthermore, signatures of demographic expansion in most populations and areas of genetic admixture were recovered throughout the AF, suggesting that forest fragmentation was also important in differentiation. Genetic admixture areas are located between large rivers suggesting that AF rivers may diminish gene flow. Our results indicated a complex and dynamic biogeographic history of Pyriglena in the AF, with vicariance, extinction, dispersal and secondary contact followed by introgression likely influencing the current patterns of genetic distribution.
Sakesphorus cristatus

Capelli, D., Batalha-Filho, H. & Japyassú, H.F. Song variation in the Caatinga suboscine Silvery-cheeked Antshrike (Sakesphorus cristatus) suggests latitude and São Francisco River as drivers of geographic variation. J Ornithol (2020). https://doi.org/10.1007/s10336-020-01779-4


Historical processes may result in patterns of differentiation among extant populations, which may lead to diversification and speciation. This is often expressed, and measured, as genetic and behavioral variation among populations. Suboscine birds acquire songs by innate mechanisms and are typically poorly studied relative to oscine birds, which may learn songs and thus develop unique dialects among populations. Behavioral features, including song, are extensively used to describe the structure and geographical variation in bird populations. In turn, this knowledge may shed light onto patterns of species diversification across ecoregions, which is particularly relevant in endemic species. Here we investigate for the first time song structure and variation in the Silvery-cheeked Antshrike, an endemic bird of a poorly studied South American dry forest, the Caatinga. We evaluate hypotheses for song diversification, correlating vocal acoustic parameters with geographic patterns and environmental variables. We measured temporal and spectral variables in the song of Sakesphorus cristatus across 14 localities spanning almost the entire range of the species’ distribution. The song presents a clear geographic pattern, and vocal variation was congruent with a barrier by the São Francisco River superimposed to a latitudinal clinal variation that was uncorrelated to climate variables. We argue that these regional differences may have a genetic basis since S. cristatus is a suboscine antbird that should not show song learning (social adaptation) and, apparently, does not have the song correlated to habitat features (acoustic adaptation). More detailed studies are required to test further hypotheses about the drivers of this potential genetic variation underlying the geographical variation in this suboscine bird song.
Rafael S Marcondes, Robb T Brumfield, A simple index to quantify and compare the magnitude of intraspecific geographic plumage colour variation in typical antbirds (Aves: Passeriformes: Thamnophilidae), Biological Journal of the Linnean Society, Volume 130, Issue 2, June 2020, Pages 239–246, https://doi.org/10.1093/biolinnean/blaa041


Intraspecific geographic phenotypic variation is a crucial theme in evolutionary biology. Comparing its magnitude across species can provide insights into its ecological and genetic correlates. Here, we developed an index, which we dub the V index, to quantify intraspecific plumage colour variation in typical antbirds (Thamnophilidae), a family which has long interested ornithologists due to a high prevalence of intraspecific variation. The V index is based on a bivariate colour space defined by brightness and redness. Its value for each species equals the mean area occupied by each of its subspecies in that colour space, divided by the area of the species. Lower values indicate greater intraspecific geographic variation. Based on this index, Thamnophilus caerulescens (Variable Antshrike) was exceptionally geographically variable compared to other thamnophilids, as previously suggested based on qualitative evidence. In general, we found that the most variable species had disjunct distributions and deep phylogeographic structure, suggesting an effect of historical population dynamics in producing geographic variation. The V index can be adapted for use with other taxa, traits, and taxonomic levels, and we expect it will instigate novel ways of thinking about phenotypic variation in birds and other animals.
Oscar Johnson, Jeffrey T. Howard, Robb T. Brumfield (2020). Systematics of a Neotropical clade of dead-leaf foraging antwrens (Aves: Thamnophilidae; Epinecrophylla). Molecular Phylogenetics and Evolution, Available online 18 September 2020,
In Press, Journal Pre-proof.


The stipple-throated antwrens of the genus Epinecrophylla (Aves: Thamnophilidae) are represented by eight species primarily found in the lowlands of the Amazon Basin and the Guiana Shield. The genus has a long and convoluted taxonomic history, with many attempts made to address the taxonomy and systematics of the group. Here we employ massively parallel sequencing of thousands of ultraconserved elements (UCEs) to provide both the most comprehensive subspecies-level phylogeny of Epinecrophylla antwrens and the first population-level genetic analyses for most species in the genus. Most of our results are robust to a diversity of phylogenetic and population genetic methods, but we show that even with thousands of loci we are unable to fully resolve the relationships between some western Amazonian species in the haematonota group. We uncovered phylogenetic relationships between taxa and patterns of population structure that are discordant with both morphology and current taxonomy. For example, we found deep genetic breaks between taxa in the ornata group that are currently regarded as species, and in the haematonota and leucophthalma groups we found paraphyly at the species and subspecies levels, respectively. As has been found in many Amazonian taxa, our phylogenetic results show that the major river systems of the Amazon Basin appear to have an effect on the genetic structure and range limits within Epinecrophylla. Our population genetics analyses showed extensive admixture between some taxa despite their deep genetic divergence. We present a revised taxonomy for the group and suggest areas for further study.

If anyone knows one of the author or if their sci-hub works to get the paper :king:
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Áurea A. Cronemberger, Alexandre Aleixo, Else Mikkelsen, Jason T. Weir. 2020. Postzygotic isolation drives genomic speciation between highly cryptic Hypocnemis antbirds from Amazonia. Evolution Accepted Article. https://doi.org/10.1111/evo.14103

How species evolve reproductive isolation in the species‐rich Amazon basin is poorly understood in vertebrates. Here we sequenced a reference genome and used a genome‐wide sample of SNPs to analyze a hybrid zone between two highly cryptic species of Hypocnemis warbling‐antbirds – the Rondonia warbling‐antbird (H. ochrogyna) and Spix's warbling‐antbird (H. striata) – in a headwater region of southern Amazonia. We found that both species commonly hybridize, producing F1s and a variety of backcrosses with each species but we detected only one F2‐like hybrid. Patterns of heterozygosity, hybrid index, and interchromosomal linkage disequilibrium in hybrid populations closely match expectations under strong postzygotic isolation. Hybrid zone width (15.4 km) was much narrower than expected (211 km) indicating strong selection against hybrids. A remarkably high degree of concordance in cline centers and widths across loci, and a lack of reduced interspecific Fst between populations close to versus far from the contact zone, suggest that genetic incompatibilities have rendered most of the genome immune to introgression. These results support intrinsic postzygotic isolation as a driver of speciation in a moderately young cryptic species pair from the Amazon and suggest that species richness of the Amazon may be grossly underestimated.

Leonardo S Miranda, Bernardo O Prestes, Alexandre Aleixo, Molecular systematics and phylogeography of a widespread Neotropical avian lineage: evidence for cryptic speciation with protracted gene flow throughout the Late Quaternary, Biological Journal of the Linnean Society, , blaa193, https://doi.org/10.1093/biolinnean/blaa193


Here we use an integrative approach, including coalescent-based methods, isolation–migration and species distribution models, to infer population structure, divergence times and diversification in the two species of the genus Cymbilaimus (Aves, Thamnophilidae). Our results support a recent and rapid diversification with both incomplete lineage sorting and gene flow shaping the evolutionary history of Cymbilaimus. The spatio-temporal pattern of cladogenesis suggests that Cymbilaimus originated in the north/western portion of cis-Andean South America and then diversified into the Brazilian Shield and Central America after consolidation of the modern Amazonian drainage and the Andean range. This evolutionary scenario is explained by cycles of range expansion and dispersal, followed by isolation, and recurrent gene flow, during the last 1.2 Myr. Our results agree with those recently reported for other closely related suboscine lineages, whereby the window of introgression between closely related taxa remains open for up to a few million years after their original split. In Cymbilaimus, introgression was recurrent between C. lineatus and C. sanctaemariae, even after they acquired vocal and ecological differentiation, supporting the claim that at least in Neotropical suboscines, full reproductive compatibility may take millions of years to evolve and cannot be interpreted as synonymous with a lack of speciation.
G. A. Bravo, B.M. Whitney, R. Belmonte-Lopes, M. R. Bornschein, N. Aristizábal, R. Beco, J. Battilana, L. N. Naka, A. Aleixo, M. R. Pie, L. F. Silveira., E. P. Derryberry, R. T. Brumfield Phylogenomic analyses reveal non-monophyly of the antbird genera Herpsilochmus and Sakesphorus (Thamnophilidae), with description of a new genus for Herpsilochmus sellowi. Ornithology, in press.

All in all, their study will focus on the genera Sakesphorus (including Sakesphoroides restored for 'Sakesphorus' cristatus) and Herpsilochmus. Let's go, be original. Shall we bet on the new name? There is already Cercomacroides, Hypocnemoides and Sakesphoroides, the next one will be Herpsilochmoides?

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