The Ovenbirds are a large family of small suboscine passerine birds found in Mexico, Central and South America. Hybridization has been documented in several genera.
The current distribution of the Rufous-fronted Thornbird (Phacellodomus rufifrons) can be explained by the “Pleistocene Arc Hypothesis” which states that dry periods might have promoted the expansion of dry forests, culminating in a continuous arc around the southern half of Amazonia from Peru to Brazil. There is evidence for recent gene flow between two subspecies in Eastern Brazil (rufifrons and specularis), suggesting there is a hybrid zone in that area (Corbett et al. 2020).
The Rufous-capped Spinetail (S. ruficapilla) and the Bahia Spinetail (S. cinerea) form a secondary contact zone in Brazil. Gene flow mainly occurs from the Bahia Spinetail into the Rufous-capped Spinetail (Batalha-Filho et al., 2019).
While investigating the phylogeographic history of the Buff-browed Foliage Gleaner (Syndactyla rufosuperciliata), a study uncovered gene flow between this species and the Russet-mantled Foliage-gleaner (Syndactyla dimidiata) in Paraguay and Brazil (Cabanne et al., 2019).
At Amazonian headwaters, hybrids between subspecies of the following species have been confirmed genetically (Weir et al., 2015): Plain-brown Woodcreeper (Dendrocincla fuliginosa), Elegant Woodcreeper (Xiphorhynchus elegans) and Wedgebill Woodcreeper (Glyphorhynchus spirurus). Reproductive isolation between Elegant Woodcreeper subspecies is mainly driven by postzygotic isolation (Pulido-Santacruz et al. 2018).
Batalha-Filho, H., Maldonado-Coelho, M., & Miyaki, C.Y. (2019). Historical climate changes and hybridization shaped the evolution of Atlantic Forest spinetails (Aves: Furnariidae). Heredity, 1.
Cabanne et al. (2019) Phylogeographic variation within the Buff-browed Foliage-gleaner (Aves: Furnariidae: Syndactyla rufosuperciliata) supports an Andean-Atlantic forests connection via the Cerrado. Molecular Phylogenetics and Evolution, 133: 198-213.
Corbett, E. C., Bravo, G. A., Schunck, F., Naka, L. N., Silveira, L. F., & Edwards, S. V. (2020). Evidence for the Pleistocene Arc Hypothesis from genome‐wide SNPs in a Neotropical dry forest specialist, the Rufous‐fronted Thornbird (Furnariidae: Phacellodomus rufifrons). Molecular Ecology, 29(22), 4457-4472.
Pulido-Santacruz, P., Aleixo, A. & Weir, J.T. (2018) Morphologically cryptic Amazonian bird species pairs exhibit strong postzygotic reproductive isolation. Proceedings of the Royal Society B, 285:20172081.
Weir, J. T., Faccio, M. S., Pulido-Santacruz, P., Barrera-Guzman, A. O. & Aleixo, A. (2015). Hybridization in headwater regions, and the role of rivers as drivers of speciation in Amazonian birds. Evolution 69, 1823-1834.