Proposal (484) to South American Classification Committee

 

Recognize Pyrrhura parvifrons

 

 

Arndt (2008) based his revision of the Pyrrhura picta complex on 283 specimens in many museums in Europe, North America and South America; he measured 240 of them. He recognized 10 species in that complex, and described a new species and two new subspecies. Arndt made no statement about the species concept he was applying. He (2006) applied the PSC in his description of new taxa as in the Aratinga mitrata complex.

 

The type specimen of Pyrrhura parvifrons is a female in the Senckenberg Museum, Frankfurt am Main, Germany, collected by Gustav Garlepp on 29 October 1885 in NE Peru, Shanusi, Yarimaguas.

 

According to his table 1, Arndt identified 7 males, 5 females and 12 unsexed birds as parvifrons; he did not mention the collections in which those specimens are deposited except for a few he mentioned in his ‘discussion’.

 

Pyrrhura parvifrons differs from all other taxa in the P. picta complex by its narrow band of red feathers on the base of the forehead, and by a green bend of the wing. In contrast to many (apparently not all!) P. roseifrons, the feather edges of breast and neck show no pink hue. The auriculars are faint dirty brown to dark brown. The species is smaller than P. roseifrons, but with a longer tail. However, in his table 1, Arndt lumped both sexes and unsexed specimens for measurements; the means of the wings are smaller in parvifrons than in roseifrons, and the tails are longer. But the ranges of measurements for both wings and tail overlap completely!

 

There are apparently two disjunct populations of parvifrons: one in an area from Shanusi, Yurimaguas, Sarayacu, and possibly Rio Cushabatay; the other one in the Santa Cecilia region and Quebrada Vainilla along the Rio Amazonas to the mouth of the Rio Orosa; birds from Tarapoto are probably intermediate with roseifrons.

 

In his discussion, Arndt stated that Joseph (2002) gave an excellent review of the picta complex in Amazonia, but that Joseph’s characterization of the taxa according to the pattern of the breast feathers is not reliable. There is in all taxa too much variation in pattern and coloration of single breast feathers as well as of the whole breast plumage as to be used as the sole character to distinguish them.

 

Arndt’s parvifrons are the birds considered by Joseph (2002) as “problematic”, and the birds named P. picta in Schulenberg et al.’s (2007) “Birds of Peru”. But Arndt found no evidence for a mixed (=hybrid?) population of P. roseifrons x P. peruviana, based on measurements (but see above). There may be, however, some gene exchange between parvifrons and roseifrons in the Tarapoto area, as the ranges of the two species are apparently connected by the Rio Huallaga. Several birds in the collections of Frankfurt and Washington from Tarapoto show intermediate characters.

 

According to Arndt (2008) there is no evidence for a connection between the two disjunct populations of parvifrons, contra Joseph’s (2002) assumption. Arndt considered them to be relict populations of a once more widely distributed taxon, which was affected genetically by P. lucianii and P. roseifrons. It may have occurred from the mouth of the Rio Tefé west along the Amazonas. The eastern population probably was displaced by roseifrons and subsequently isolated, whereas there was limited amalgamation with the latter species in a restricted area along the Andes. The eastern population is more similar to lucianii in their bluish cheeks, the bluish forehead and the dark auriculars. Arndt speculated that the restricted distribution is caused by the Rio Amazonas in the north, and by competition with the larger taxa roseifrons and rupicola in the south. The very limited gene exchange between parvifrons and roseifrons is no reason for Arndt to treat both forms as conspecific. There is an area of possible sympatry between both taxa in the Rio Cushabatay area (77 km WNW of Contamana), where both taxa have been collected (specimens at LSU and Lima).

 

The taxonomy of the Pyrrhura picta complex is notoriously difficult. Although Arndt is certainly an expert in parrots, I am not convinced by his arguments. There are no statistical data on measurements, and little is known about the actual degree of hybridization between the taxa involved. Also lacking are ecological data for parvifrons; in fact, there is little knowledge about the ecology and ethology of all taxa in the complex. Molecular genetic data (at least mtDNA, perhaps microsatellites or sex chromosome linked loci might perform better) may also fail to solve the problem, as intergradation and perhaps also incomplete lineage sorting may play a role in this group. In any case, as Martens & Bahr (Vogelwarte 48[2010]: 97-117) stated, more field and genetic data are necessary to resolve the puzzle about the Amazonian P. picta complex.

 

Norbert Bahr, May 2011

 

 

Comments from Stiles:  A tentative NO.  Bahr’s doubts seem reasonable given the complexity of the situation in this notoriously difficult group – more data and better analysis seem required.  However, I would be interested to hear opinions from those in and outside of SACC who know these birds better than I do!

 

Comments from Robbins: “NO.  A far more complete data set (larger sample sizes with associated genetic data) are needed (with all details published) in order to clarify relationships with this seemingly intractable group of parakeets.”

 

Comments from Remsen: NO.  Age, sex, and individual variation must be worked out rigorously in this group, as well as potential season movements that might give the illusion of breeding sympatry.  Arndt is on to interesting variation – now, someone needs to determine the source of that variation before taxonomy is changed.”

 

Comments from Pacheco: “NO.  Considero desejável aguardar mais informaćčo e melhores amostras para imunizar este caso das incertezas – enumeradas por Bahr – que permanecem sem respostas.”

 

Comments from Jaramillo: “NO – I think the possible intergradation between it and roseifrons needs better characterization. Parrots are troublesome, hybridization occurs in various taxa, and plumage characters are variable in many species. I do think that vocal and ecological information is paramount to understanding their taxonomy, and it is somewhat lacking in this situation. Also, I am not clear as to why this is not a subspecies rather than a species based on BSC.”

 

Comments from Zimmer: “NO.  I’m not convinced that anyone has the correct handle on this group (as Mark states “seemingly intractable”), and without a more comprehensive data set, it seems as if recognizing another taxon only adds to the confusion.”

 

Comments from Pérez-Emán:  “NO. More evidence is needed to resolve this difficult group of species.”