Neotropical savanna birds (1 Viewer)

[albertonykus]

Lima-Rezende, C.A., G.S. Cabanne, A.V. Rocha, M. Carboni, R.M. Zink, and R. Caparroz (2022)
A comparative phylogenomic analysis of birds reveals heterogeneous differentiation processes among Neotropical savannas
Molecular Ecology (advance online publication)
doi: 10.1111/mec.16487

The main objective of this study is to evaluate biogeographic hypotheses of diversification and connection between isolated savannas north (Amazonian savannas) and south (Cerrado core) of the Amazon River. To achieve our goal, we employed genomic markers (genotyping-by-sequencing) to evaluate the genetic structure, population phylogenetic relationships, and historical range shifts of four Neotropical passerines with peri-Atlantic distributions: the Narrow-billed Woodcreeper (Lepidocolaptes angustirostris), the Plain-crested Elaenia (Elaenia cristata), the Grassland Sparrow (Ammodramus humeralis), and the White-banded Tanager (Neothraupis fasciata). The population genetic analyses indicated that landscape (e.g., geographic distance, landscape resistance, and percentage of tree cover) and climate metrics explained divergence among populations in most species, but without indicating a differential role between current and historical factors. Our results did not fully support the hypothesis that isolated populations at Amazonian savannas have been recently derived from the Cerrado core domain. Intraspecific phylogenies and gene flow analyses supported multiple routes of connection between the Cerrado and Amazonian savannas, rejecting the hypothesis that the Atlantic corridor explains the peri-Atlantic distribution. Our results reveal that the biogeographic history of the region is complex and cannot be explained by simple vicariant models.

 

[albertonykus]

Lopes, L.E., L.P. Gonzaga, M. Rodrigues, and J.M.C. da Silva (2024)
Distinct taxonomic practices impact patterns of bird endemism in the South American Cerrado savannas
Zoological Journal of the Linnean Society (advance online publication)
doi: 10.1093/zoolinnean/zlae019

Identifying endemic species and the areas of endemism delimited by them is central to biogeography. However, the impact of distinct taxonomic approaches on these patterns is often neglected. We investigated how three different taxonomic approaches impact the patterns of bird endemism in the Cerrado. The first two approaches (at species and subspecies levels) were based on traditional taxonomy based on the biological species concept. The third approach was based on a revised alternative taxonomy that sought to identify evolutionarily significant units (ESUs). In this third approach, after identifying the endemic taxa using traditional taxonomy, we revised their validity, removing biologically meaningless entities. We then detected the areas of endemism delimited by these endemic taxa under the three taxonomic approaches. We found that traditional taxonomy at the species level underestimated bird endemism by ignoring some ESUs that were considered subspecies. In contrast, traditional taxonomy at the subspecies level overestimated bird endemism, leading to the recognition of spurious areas of endemism because several of the purported endemic subspecies were taxonomic artefacts. The revised taxonomy provided a more refined picture of patterns of avian endemism in the Cerrado, suggesting that the use of ESUs improves the results of biogeographical analysis.

 

[njlarsen]

I do not seem to have access to the full paper. I wonder about their definition of an ESU and how that relates to for example a phylogenetic species.
Niels

 

[Mysticete]

I do not seem to have access to the full paper. I wonder about their definition of an ESU and how that relates to for example a phylogenetic species.
Niels

This is why I don't like esu...it's a weird ill defined unit that can mean anything from a biological species down to just a population of a species in one part of their range