Sunday, September 17, 2023

[Ornithology • 2023] Phylogenetic Relationships and Biogeography of the Ancient Genus Onychorhynchus (Passeriformes: Onychorhynchidae) suggest Cryptic Amazonian Diversity


Distribution of Onychorhynchus

in Reyes, Bates, Naka, Miller, Caballero, ... et Tello, 2023. 

Abstract
We examined phylogeographic patterns and cryptic diversity within the royal flycatcher, Onychorhynchus coronatus (Aves: Onychorhynchidae), a widespread Neotropical lowland forest tyrant flycatcher. A phylogeny of the six recognized subspecies was constructed from mtDNA sequence data of the NADH dehydrogenase subunit two gene, using Bayesian Inference and Maximum Likelihood methods. Phylogenetic analyses revealed high levels of intraspecific divergence within O. coronatus, supporting the existence of at least six independent lineages. The phylogenetic results uncovered the following relationships: (O. c. swainsoni [Southern Atlantic Forest], (O. c. coronatus [western Amazonia], (O. c. castelnaui [eastern Amazonia], (O. c. mexicanus [Central America], (O. c. occidentalis [Tumbesian], O. c. fraterculus [extreme northwestern South America])))). Biogeographic and dating analyses suggest that vicariant and dispersal events acted across approximately six million years to influence lineage diversification within this genus. Some of those events include the formation of the Amazon River and its tributaries, Andean uplift, and climatically induced vegetational shifts. Phylogenetic and biogeographic analyses of O. coronatus lineages support a hypothesis of area relationships in which the first divergence event isolated the Southern Atlantic Forest from Amazonia during the Late Miocene/Early Pliocene. This event was followed by the split of western and eastern Amazonia at the Early/Late Pliocene, the divergence of cis- and trans-Andean lowland regions also at the Early/Late Pliocene, the split between Central America and the extreme northwestern South America/Tumbes at the Early/Middle Pleistocene, and the split between extreme northwestern South America and Tumbes at Middle/Late Pleistocene. Subsequent divergence of the southern and northern populations in the western and eastern Onychorhynchus lineages took place during the Pleistocene. Comparison of phylogenetic trees and patterns in Onychorhynchus with those from published work suggests that across large New World radiations such as the Suboscines, some co-distributed lineages began to diverge long before others, which exemplifies the complexity of their evolutionary history.

Keywords: cryptic diversity, diversification, Neotropical, Onychorhunchus, phylogeny


Distribution of Onychorhynchus, including collecting localities for the specimens that were used in this study. Points indicate sample collection localities and numbers refer to unique specimen IDs, which are also referenced in Fig. 2, 3 , and Supporting information. Illustrations of Onychorhynchus lineages showing plumage coloration differences. Illustrations by Francy Tamayo.

Conclusions
Our study highlights the complex diversification patterns of the Neotropical lowlands and stresses the importance of assessing phylogenetic relationships of complex taxa with large and patchy distributions. Onychorhynchus constitutes an ancient radiation whose ancestral lineage originated in the extensive ‘pan-Amazonian' region in the Late Paleogene/Early Miocene. Onychorhynchus started radiating during the Late Miocene/Early Pliocene with an expansion out of Amazonia to the Atlantic Forest, followed by an Early/Late Pliocene splitting of an Amazonian ancestral lineage to form the western and eastern Amazonian clades, and a subsequent single Early/Late Pliocene trans-Andean colonization from western Amazonia that originated the ancestral trans-Andean clade. The trans-Andean lineages originated during the Early to Late Pleistocene.

Furthermore, this study helped to reveal independently evolving lineages that might have to be treated as separate species with different conservation concerns. Complementary studies that include nuclear DNA, morphology, niche differentiation, and vocalizations with thorough sampling throughout the Onychorhynchus distribution are needed to fully resolve the evolutionary relationships and delimit species within this genus.

 
Pamela Reyes, John M. Bates, Luciano N. Naka, Matthew J. Miller, Isabel Caballero, Catalina Gonzalez-Quevedo, Juan L. Parra, Hector F. Rivera-Gutierrez, Elisa Bonaccorso and José G. Tello. 2023. Phylogenetic Relationships and Biogeography of the Ancient Genus Onychorhynchus (Aves: Onychorhynchidae) suggest Cryptic Amazonian Diversity. Journal of Avian Biology. DOI: 10.1111/jav.03159