Taxonomic diversity and distributions
In order to delimit the basal taxonomic units, or phylogenetic species (Cracraft 1983), within Pionus, we examined 257 specimens of all named subspecies of Pionus in the collections of the American Museum of Natural History and consulted the literature.
Distributional data were obtained from the literature, and we provide here both the main altitudinal range of each taxon and the maximum and minimum altitudes in which individuals of each taxon have been recorded. Although parrots can seasonally move altitudinally in search for food, especially to lower altitudes, the species of the three montane clades show preferences to the higher ecological zones within their known distributions.
Following are the terminals recognized in our phylogenetic and biogeographic analyses, along with their diagnoses as distinct basal taxa, taxonomic notes, altitudinal and geographical distributions. Areas of endemism from Cracraft (1985), distributional and altitudinal data from Forshaw (1989), Juniper & Parr (1998), Fjeldsa & Krabbe (1990), Meyer de Schauensee & Phelps (1978), Hilty & Brown (1986), Ridgely & Greenfield (2001), Clements & Shany (2001), Stiles & Skutch (1990), Ridgely & Gwyne (1992).
Pionus menstruus species-group [blue-headed parrots]
Pionus menstruus
Diagnosis. Head and neck all dark bright blue; inconspicuous red on base of some throat feathers; lower breast, belly and flanks deep green; feathers of rump deep green; undertail coverts red, tipped green.
Distribution: all lowland Amazonian areas of endemism (Guyana, Imeri, Napo, Inambari, Rondonia, Para, and Belem)
Altitudinal Range: sea level to 1100m (recorded at 1500m)
Pionus reichenowi
Diagnosis. Head and neck all dull lightish blue; no red on throat; lower breast, belly and flanks blue and green; feathers of rump bluish-green; undertail coverts red, tipped blue.
Distribution: Serra do Mar Center
Altitudinal Range: sea level, no further information available
Pionus rubigularis
Diagnosis. Head and neck all bright (iridescent) deep blue; moderately extensive bright red on throat; lower breast, belly and flanks bright green; feathers of rump bright green; undertail coverts red, tipped bright green.
Distribution: Chocó and Nechí Centers, Panama and southern Costa Rica
Altitudinal Range: sea level to 1100 m (recorded at 1500m)
Taxonomic note: Although these three phylogenetic species are well-defined morphologically, genetic distances among them are low (between 0.4% and 1.7%, SI Table 7), and their interrelationships are not resolvable. Despite this, among the 12 sampled individuals for the molecular data, each taxon was represented by a monophyletic clade, and there were four fixed differences diagnostic for P. menstruus, four for P. rubrigularis, and seven for P. reichenowi.
Pionus chalcopterus species-group
Pionus chalcopterus
Diagnosis. Plumage highly melanized, with sides of head, lower breast and belly deep bluish black; throat whitish, suffused with light yellow-orange; upper breast with reddish-orange patch; shoulder and secondaries bronze; upper tail coverts dark blue; tail blue; undertail coverts red, with no terminal light band; undersides of primaries deep greenish blue; upper primaries dark blue.
Distribution: Perijan Montane Center and North Andean Center
Altitudinal Range: 1400m - 2400m (recorded from 120m to 2800m)
Pionus cyanescens
Diagnosis. Back less bronze green than P. chalcopterus; in plumage, this taxon is inconsistently diagnosable from P. chalcopterus.
Distribution: North Andean Center
Altitudinal Range: 1400 - 2400 m (recorded from sea level to 2800m)
Pionus senilis
Diagnosis. Forehead and forecrown white; sides of head and hind neck dark blue-green; throat white; breast feathers banded dark reddish brown, green, and blue; primaries bright blue; tail greenish blue; shoulder feathers dull green, tipped bronze; undersides of primaries bright blue-green; upper primaries bright blue.
Distribution: Mexico to Panama
Altitudinal Range: sea level to 1600 m (recorded at 2300m)
Pionus tumultuosus species-group
Pionus tumultuosus
Diagnosis. Feathers of forehead and entire crown deep rose-red, with white bases; sides of head dark, streaked light red; throat dark rose-red, breast dark blue; primaries bright green; tail green; shoulder feathers deep green; undersides of primaries light green; upper primaries bright green.
Distribution: Peruvian Andean Center
Altitudinal Range: mainly 2000-3000 (recorded 1400-3300)
Pionus seniloides
Diagnosis. Forehead and forecrown dirty white with suffused orange tinge; sides of head blackish, streaked white; hindcrown and neck white, tipped dark with green tinge; throat dull white; breast dull green; primaries bright green; tail green; shoulder feathers deep green; undersides of primaries darkish green; upper primaries bright green.
Distribution: Perijan Montane Center, North Andean Center, Peruvian Andean Center
Altitudinal Range: mainly 2000-3000 (recorded 1500-3200m)
Taxonomic note: O’Neill and Parker (1976) noted the head color differences between these two forms, but thought they did not differ sufficiently either morphologically or ecologically to justify their treatment as different species. The two forms are diagnosably distinct, and sequences from one P. t. tumultuosus from Cuzco, Peru and two P. t. seniloides from Ecuador indicate that genetic divergence between them is around 1.4% (table S6), which suggests they are likely to be genetically diagnosable as well once better sampling is undertaken. It remains to be seen whether populations of these two phylogenetic species are allopatric.
Pionus maximiliani species-group
Pionus maximiliani
Diagnosis. Upper breast pale blue (a little brighter than in P. melanoblepharus); breast and belly light to medium yellow-green; upper parts light green; anterior edges of primaries green; undertail coverts lightish red.
Distribution: Caatinga Center
Altitudinal Range: sea level to 1500m
Pionus melanoblepharus
Diagnosis. Upper breast deep dull blue; breast and belly darkish green with faint bluish cast; upper parts dark-green; anterior edge of primaries blue-green; deep red undertail coverts.
Distribution: Campo Cerrado and Paraná Centers
Altitudinal Range: sea level to 1500m
Pionus siy
Diagnosis. Smaller than P. lacerus to which it is most similar; back and wing coverts/ tertials less extensivly dark yellow green; upper breast with dark purple blue restricted to feather tips (green basally); lower breast and belly light yellow-green.
Distribution: Chaco Center
Altitudinal Range: sea level to 1500m
Pionus lacerus
Diagnosis. Very large body size, upper breast extensive dark purple blue; back extensive dark yellow green; wing coverts, tertials dark yellow-green; lower breast and belly dark yellow-green; undertail coverts deep red.
Distribution: Chaco Center
Altitudinal Range: sea level to 2000m
Taxonomic note: Three or four subspecies within a polytypic P. maximiliani have been traditionally recognized. Each is here accepted to be diagnosable but with some caveats. The form melanoblepharus has often been combined with maximiliani (Peters 1937, Smith 1960) and indeed our results show they are sister-taxa and close genetically (maximum of 0.1% genetic distance, table S6) Nevertheless, they are quite distinct morphologically and have distinct, although apparently parapatric, distributions in two well-recognized areas of endemism. P. siy and P. lacerus are also sister-taxa and genetically very similar, but they are also distinct morphologically. Genetic data presented in this paper indicate these two sister-pairs are rather deeply divergent (maximum of 1.7% genetic distance table S6) even though they are said to “intergrade” with one another (Forshaw 1989) wherever they come in contact. If that is the case, then nonsister-species are interbreeding. Identifying these four as distinct basal taxa recognizes their complex and interesting biogeographic history. The nature of potential interbreeding needs further study.
Pionus sordidus species-group [red-billed parrots]
Pionus sordidus
Diagnosis. Upper breast and belly variably light green/yellow green; indistinct light barring; back with darkish green feathers with narrow light yellow-green terminal bar; throat and upper breast bright green with bluish tinge. Male with red feathers on forecrown.
Distribution: Venezuelan Montane Center
Altitudinal Range: 450-1850m (recorded 100-3000m)
Pionus ponsi
Diagnosis. Throat with mostly green feathers, some tipped with deep blue; back feathers deep dark green with dull yellow-green terminal bar.
Distribution: Perijan Montane Center
Altitudinal Range: 450-1850m (recorded 100-3000m)
Pionus antelius
Diagnosis. Upper breast, belly and upper parts light olive green, feathers with broad terminal light yellowish, giving scalloped appearance; throat and upper breast turquoise-green; back with light yellow-green feathers with broad yellowish terminal bar.
Distribution: Parian Center
Altitudinal Range: 450-1850m (recorded 100-3000m)
Pionus saturatus
Diagnosis. Throat and upper breast bright turquoise-blue; upper breast and belly darkish olive green, most feathers lacking light terminal bar; feathers of back dark green without light terminal bar.
Distribution: Santa Marta Center
Altitudinal Range: 200-2400m
Pionus corallinus
Diagnosis. Plumage with bluish cast; feathers of crown and hind neck with broad, deep blue terminal band and deep blue-green subterminal; side of head and lateral throat narrow, with blue terminal band, darkish blue-green subterminal; belly with blue-green cast; upper parts darker bluish green in contrast to dark green of P. mindoensis.
Distribution: North Andean Center, Peruvian Andean Center
Altitudinal Range: 1200 - 2300 (recorded 1000-2600)
Pionus mindoensis
Diagnosis. Plumage greener than in P. corallinus; belly with green feathers, without blue-green cast; crown scalloped, terminal band narrow dull blue, subterminal portion of feathers bronzy green; side of neck and lateral throat with feathers having narrow blue terminal and yellow-green subterminal bands.
Distribution: North Andean Center
Altitudinal Range: 1200 - 2300 (recorded 1000-2600)
Taxonomic note: None of the species in the P. sordidus species-group are represented by many specimens. There are clear morphological differences between (corallinus, mindoensis) and (saturatus, antelius, sordidus, ponsi), but not so much within each group. The molecular data agree with the morphological observations. P.corallinus and P.mindoensis are very closely related, with very low genetic distance (0 to 0.9%, table S6). P.antelius, P.sordidus and P.ponsi are also very closely related (p-distances of 0.4% or less table S6), but P.saturatus is more divergent (p-distances of 2.4% to 2.9% table S6). This relatively high genetic distance of P. saturatus is not reflected in plumage characters, as it is not markedly different from P.antelius, P. sordidus, or P. ponsi. All are diagnosably distinct in their plumage, but not strongly so.
Pionus fuscus
Pionus fuscus
Diagnosis. Underparts with dull red barring; upper parts dark, dull blue; feathers of back with light brown terminal bar.
Distribution: Guyanan Center, Perijan Montane Center
Altitudinal Range: mostly below 600m (up to 1000m), 1200-1800m in Perijá
References
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Cracraft, J. 1983 Species concepts and speciation analysis. Current Ornithology1, 159-187.
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Forshaw, J. 1989 Parrots of the World, 3rd ed. Melbourne: Landsdowne Editions.
Hilty, S. L. & Brown, W.L. 1986 A Guide to the Birds of Colombia. Princeton: Princeton Univ. Press.
Juniper, T. & Parr, M. 1998. Parrots - A guide to the parrots of the world. New Haven: Yale Univ. Press
Meyer de Schauensee, R. & Phelps, W. H. 1978 A Guide to the Birds of Venezuela. Princeton: Princeton Univ Press.
O'Neill, J. P. & Parker III, T. A. 1976 Taxonomy and range of Pionus "seniloides" in Perú. Condor79, 274.
Peters, J. L. 1937 Check-list of the birds of the world. Cambridge: Harvard Univ. Press.
Ridgely, R. S. & Greenfield, P. J. 2001 The Birds of Ecuador. Ithaca: Cornell Univ. Press.
Ridgely, R. S. & Gwynne, J. A. 1992 A Guide to the Birds of Panama. Princeton: Princeton Univ. Press.
Smith, E. T. 1960 Review of Pionus maximiliani (Kuhl). Fieldiana Zoology39, 379-385.
Stiles, F. G. & Skutch, A. F. 1990 A Guide to the Birds of Costa Rica. Ithaca: Cornell Univ. Press.
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