• 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.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

(Not only) Thamnophilidae (1 Viewer)

Bolívar-Leguizamón, S. D., Bocalini, F., Silveira, L. F., & Bravo, G. A. (2024). The role of biogeographical barriers on the historical dynamics of passerine birds with a circum-Amazonian distribution. Ecology and Evolution, 14, e10860. https://doi.org/10.1002/ece3.10860

Common distributional patterns have provided the foundations of our knowledge of Neotropical biogeography. A distinctive pattern is the “circum-Amazonian distribution”, which surrounds Amazonia across the forested lowlands south and east of the basin, the Andean foothills, the Venezuelan Coastal Range, and the Tepuis. The underlying evolutionary and biogeographical mechanisms responsible for this widespread pattern of avian distribution have yet to be elucidated. Here, we test the effects of biogeographical barriers in four species in the passerine family Thamnophilidae by performing comparative demographic analyses of genome-scale data. Specifically, we used flanking regions of ultraconserved regions to estimate population historical parameters and genealogical trees and tested demographic models reflecting contrasting biogeographical scenarios explaining the circum-Amazonian distribution. We found that taxa with circum-Amazonian distribution have at least two main phylogeographical clusters: (1) Andes, often extending into Central America and the Tepuis; and (2) the remaining of their distribution. These clusters are connected through corridors along the Chaco–Cerrado and southeastern Amazonia, allowing gene flow between Andean and eastern South American populations. Demographic histories are consistent with Pleistocene climatic fluctuations having a strong influence on the diversification history of circum-Amazonian taxa, Refugia played a crucial role, enabling both phenotypic and genetic differentiation, yet maintaining substantial interconnectedness to keep considerable levels of gene flow during different dry/cool and warm/humid periods. Additionally, steep environmental gradients appear to play a critical role in maintaining both genetic and phenotypic structure.
 
Integrative taxonomy of Cercomacroides serva (Sclater, 1858) demonstrates the validity of C. hypomelaena (Sclater, 1890) comb. nov. (Aves: Thamnophilidae).
Cercomacroides serva is widely distributed in northern South America. However, this species has never been thoroughly evaluated taxonomically. We conducted a taxonomic study of three taxa currently classified under Cercomacroides serva, based on a study of 307 skins and 145 recordings of male loudsongs. Females from the northwest Amazonian population differ qualitatively from populations from the southwest Amazon in the coloration of the upperparts, primary, and tail. Male loudsongs are superficially similar between these two populations, but the shape of the notes differs significantly. There is no evidence of intergradation or clinal variation in female plumage or male loudsongs. Based on differences in plumage coloration, loudsongs, and lack of evidence of intergradation, we suggest that two species are best recognized. The name Cercomacroides serva is here restricted to populations north of the Marañon River in Peru, to the north in Ecuador, and in southwestern Colombia. The name Cercomacroides hypomelaena comb. nov. is revived. This species is found south of the Marañon River, and on both banks of the Ucayali River in Peru, to the eastern left bank of the Madeira River in Brazil, and in northern Bolivia.
 

Users who are viewing this thread

Back
Top