Two new species of tapaculo

Tapaculos Rhinocryptidae of the genus Scytapolus form a complex group of many taxa close in morpholgy but yet genetically often quite distinct. Plumage is not a reliable indicator for specific differences, which are better unraffled by genetic studies and studies of vocalizations. Currently, c 40 species are recognized, a number that may grow further when research continues. A new species of tapaculo was recently described (Cuervo, A M, Cadena, C D, Krabbe, N & Renjifo, L M 2005. Scytapolus stilesi, a new species of tapaculo (Rhinocryptidae) from the Cordillera Central of Colombia. Auk 122: 445-463). The description is based on a series of eight specimens taken in 2002 and comparative analyses of vocalizations, mitochondrial DNA sequences and distribution. Both the vernacular and scientific name, Stiles's Tapaculo Scytalopus stilesi, honour F Gary Stiles, an ornithologist who has played a prominent role in the research on Neotropical birds in the last three decades. Stiles's Tapaculo is endemic to Colombia. It ranges in the northern half of the Cordillera Central of the Colombian Andes in the departments of Antioquia, Caldas and Risaralda, in cloud forests between 1420 and 2130 m above sea level. It was found at 21 sites on both slopes of the Cordillera Central. The song, calls and female song of the new species differ distinctly from those of all other known Scytalopus taxa. Phylogenetic analyses based on sequences of the cytochrome-b gene strongly suggest affinities with Ecuadorean Tapaculo S robbinsi of south-western Ecuador (first described in 1997) and with two as-yet-undescribed tapaculos from the Colombian Andes. Stiles's Tapaculo coexists locally with - but ecologically segregated - from Northern White-crowned S atratus, Blackish S latrans and Spillmann's Tapaculo S spillmanni. The mid-elevation premontane wet forests to which the new species is restricted have been subject to severe deforestation and fragmentation. The species is, however, relatively common in continuous mature-forest remnants, large primary-forest fragments, riparian forests and tall secondary-forest patches. The researchers employed a geographic information system (GIS) approach to model the potential distribution of the new species and assess its conservation status under the criteria of the International Union for the Conservation of Nature (IUCN). Stiles's Tapaculo does not qualify as 'threatened' according to these criteria but it should be regarded as 'near-threatened'. The new species coexists with numerous threatened bird species that are in need of more effective conservation.

Partially the same group of authors was involved in describing yet another tapaculo, Upper Magdalena Tapaculo Scytalopus rodriguezi, from the upper Magdalena valley, at 2200 m above sea level on the eastern slope of the Cordillera Central, Colombia (Krabbe, N, Salaman, P, Cortés, A, Quevedo, A, Ortega, L A & Cadena, C D 2005. A new species of Scytapolus tapaculo from the upper Magdalena Valley, Colombia. Bull Br Ornithol Club 125: 93-108). It is named after José Vicente Rodríguez Mahecha, a well-known Columbian ornithologist. The new species appeared to have already been heard and tape-recorded in the 1980s close to the type locality (Finca Merenberg). Although the song was quite unlike any other known tapaculo song, it was considered possible that it belonged to White-crowned Tapaculo S atratus confusus of which the vocalizations were unknown at the time. Because of the political instability in the region, it was too dangerous to do field work there and it was not until 2002 that recordings of vocalizations of S atratus confusus became available. These were very different from those of the Finca Merenberg birds, making it likely that the latter involved an undescribed new taxon. Finally, the Finca Merenberg area was visited in 2003, and three specimens (males) were taken of which vocalizations were first tape-recorded. Additional recordings of five or six males were obtained at Finca Merenberg and a nearby site. These are the only two locations of the species known so far.
As was to be expected, the plumage of the new species is very similar to that of other Scytalopus but the song and call are very distinctive. Tissue of the new species was used in an analysis of mt-DNA sequences as part of a broader research into the phylogeny of Scytalopus by the same group of researchers, the results of which are to be published later. One of the results was that S rodriguezi appears to be a rather old taxon within the group. ENNO B EBELS & ANDRÉ J VAN LOON