Eupsittula, Bonaparte, 1853

Smith, Brian Tilston, Thom, Gregory & Joseph, Leo, 2024, Revised Evolutionary And Taxonomic Synthesis For Parrots (Order: Psittaciformes) Guided By Phylogenomic Analysis, Bulletin of the American Museum of Natural History 2024 (468), pp. 1-87 : 41-42

Eupsittula

Eupsittula consists of five mostly green small parakeets with long, graduated tails that occur from Mexico to Paraguay. The concatenated and species trees are in agreement and resolved, except for the placement of E. aurea . This species ranges from Suriname and northeastern Brazil to northwestern Argentina. The concatenated tree had South American E. aurea sister to the two Central American species, E. nana and E. canicularis , with 80% ultrafast bootstrap support (fig. 9). Eupsittula aurea and E. canicularis are the only two species in the clade that have orange foreheads. In contrast, the species tree had E. aurea as sister to E. pertinax and E. cactorum in an all South American grouping with a local posterior probability of 1. Provost et al. (2018) had E. aurea grouping with E. nana and E. canicularis , but the position of Central American E. canicularis was unresolved. Resolving relationships among these five species is important biogeographically because it will help determine when Eupsittula first dispersed into Central America, which seems the most likely direction of dispersal. All the nodes within the clade have mean estimates that fall within the past three million years (fig. 9).

Psittacara Psittacara comprises medium- to small-sized parakeets with long, attenuated tails and are mostly green. They are remarkable among parrots and indeed all birds for the highly irregular “scattered” distribution of red in their plumage, mostly about the head, tibial feathering (thighs), underwing coverts, and particularly their contour plumage. Some species also have yellow in the underwing. Attempts to delimit species using plumage color (e.g., Arndt, 2006), particularly the extent of red plumage on the head, are now understood to produce paraphyletic species.

Relationships among the species were poorly resolved but nonetheless suggest geographically cohesive clades with varying levels of support. There are three clades of note: (1) P. mitrata and P. frontatus , species distributed from Peru to Argentina that occur up to 3500 m; (2) P. wagleri , P. finschi , P. mitratus , P. erythrogenys , and P. leucophthalmus , a widely distributed clade east and west of the Amazon; and (3) P. chloropterus , P. euops , P. holochlorus , P. brevipes , P. rubritorquis , and P. strenuus of the Caribbean, Central America, and Mexico. Given the strong geographic adjacency of species in this clade, it is most likely that the extinct P. maugei , formerly of Puerto Rico, was closely related to P. chloropterus and P. euops of Hispaniola and Cuba, respectively. The whole radiation was dated to have occurred within 0.6–6.7 Mya (fig. 9). This includes multiple colonization events of Central America dated to 2.2 and 3.1 Mya and dispersal into the Caribbean at 1–5.1 Mya (fig. 9).

Given the number of poorly resolved nodes and nonmonophyly of traditionally recognized species, which we discuss in more detail below, Psittacara is a high priority for a more detailed study. Peters (1937) considered P. frontatus conspecific with P. wagleri , and Collar (1997) suggested that P. wagleri and P. mitrata may be conspecific. Both are inconsistent with the phylogeny (see also Collar et al., 2020). Psittacara frontatus was formerly recognized as a subspecies of P. wagleri and, based on our analyses, they are not closely related. Psittacara frontatus of the Pacific slope and central Andes of Peru and Bolivia and P. mitratus of the southern Andes, branch sequentially at the base of the Psittacara clade although their relationship had 78% ultrafast bootstrap support (fig. 9). Moreover, all nodes in the clade of South and Central American Psittacara (clade 2, above) had low support values.

The resolution of relationships within clade 3 containing taxa in Central America, Mexico, and Cuba /Hispaniola was better, but there were several key nodes that were not also strongly supported (fig. 9). The clade containing the four species of Psittacara ( P. holochlorus , P. strenuus , P. rubritorquis , and P. brevipes ) from Mexico and northern Central America had high support. Within this clade, only the placement of P.brevipes of Socorro Island was weakly supported as sister to P. strenuus of southern Mexico to Guatemala and P. rubritorquis of Central America. The clade also included P. holochlorus of Mexico (and extreme southeastern Texas where the origin of its populations is unclear; Uehling et al., 2019) as sister to the other three species. However, this relationship could not be confirmed because of low support for the placement of P. brevipes (fig. 9). Within clade 3, the Psittacara of Mexico and Central America are sister to the two Caribbean species, P. chloropterus of Hispaniola and P. euops of Cuba, but this relationship was poorly supported (UFBS = 61%).