Thursday, February 27, 2020

[Ornithology • 2020] Untangling Cryptic Diversity in the High Andes: Revision of the Scytalopus [magellanicus] complex (Rhinocryptidae) in Peru reveals Three New Species

New Scytalopus taxa from the Peruvian Andes. 
(Upper left) Adult male and female of Jalca Tapaculo, Scytalopus frankeae from Huánuco. 
(Upper right) Male Scytalopus frankeae from Junín. 
(Lower left) Adult males of Ampay Tapaculo, Scytalopus whitneyi (left from Apurímac, right from Ayacucho). 
(Lower right) Adult male (top) and female (below) of White-winged Tapaculo, Scytalopus krabbei. 

in Krabbe, Schulenberg, Hosner, Rosenberg, Davis, et al., 2020. 
Watercolor painting by Jon Fjeldså.

Tropical mountains feature marked species turnover along elevational gradients and across complex topography, resulting in great concentrations of avian biodiversity. In these landscapes, particularly among morphologically conserved and difficult to observe avian groups, species limits still require clarification. One such lineage is Scytalopus tapaculos, which are among the morphologically most conserved birds. Attention to their distinctive vocal repertoires and phylogenetic relationships has resulted in a proliferation of newly identified species, many of which are restricted range endemics. Here, we present a revised taxonomy and identify species limits among high-elevation populations of Scytalopus tapaculos inhabiting the Peruvian Andes. We employ an integrated framework using a combination of vocal information, mitochondrial DNA sequences, and appearance, gathered from our own fieldwork over the past 40 yr and supplemented with community-shared birdsong archives and museum specimens. We describe 3 new species endemic to Peru. Within all 3 of these species there is genetic differentiation, which in 2 species is mirrored by subtle geographic plumage and vocal variation. In a fourth species, Scytalopus schulenbergi, we document deep genetic divergence and plumage differences despite overall vocal similarity. We further propose that an extralimital taxon, Scytalopus opacus androstictus, be elevated to species rank, based on a diagnostic vocal character. Our results demonstrate that basic exploration and descriptive work using diverse data sources continues to identify new species of birds, particularly in tropical environs.

Keywords: integrated taxonomy, Neotropics, systematics, tapaculo, vocalizations

New Scytalopus taxa from the Peruvian Andes.
(Upper left) Adult male and female of Jalca Tapaculo, Scytalopus frankeae from Huánuco. (Upper right) Male Scytalopus frankeae from Junín.
(Lower left) Adult males of Ampay Tapaculo, Scytalopus whitneyi (left from Apurímac, right from Ayacucho). (Lower right) Adult male (top) and female (below) of White-winged Tapaculo, Scytalopus krabbei.
Watercolor painting by Jon Fjeldså.

Scytalopus krabbei sp. nov. 
[T. S. Schulenberg, D. F. Lane, A. J. Spencer, F. Angulo, and C. D. Cadena] 
White-winged Tapaculo

Etymology: The modern knowledge of the systematics of Scytalopus, including recognition of a level of diversity in the genus that would have astounded earlier generations of ornithologists, is largely due to Niels K. Krabbe, through his careful and thorough research both in the field and in the collection. Having himself contributed to the descriptions of no fewer than 7 new taxa of Scytalopus, we take great pleasure in taking the opportunity to name this new species in honor of our friend and colleague. The proposed English name refers to the small patch of white on the wing coverts, a feature—otherwise unusual in tapaculos—that is present on all known S. krabbei specimens.

Scytalopus frankeae sp. nov. 
[K. V. Rosenberg, T. J. Davis, G. H. Rosenberg, P. A. Hosner, M. B. Robbins, T. Valqui, and D. F. Lane] 
Jalca Tapaculo

Etymology: We are pleased to name this new tapaculo in honor of Dr. Irma Franke, our friend, colleague, former curator of the bird collection at the MUSM, and a major contributor to Peruvian ornithology for over 30 yr. It is especially fitting to name this taxon after her because she participated in the Millpo expedition that discovered the bird in 1985. The recommended English name uses a local Peruvian term for puna and páramo habitat (“jalca”) that has tussock grasses as a primary component, which was the habitat primarily used by the species at the type locality (although less so in Junín). Colloquially, this species has been called Millpo Tapaculo. However, we consider this name to be inappropriate, primarily because Millpo is now known to be at the geographic periphery of the range of the species. Our proposed English name is more reflective of the habitat of S. frankeae throughout its distribution.

Scytalopus whitneyi sp. nov. 
[N. K. Krabbe, J. Fjeldså, P. A. Hosner, M. B. Robbins, and M. J. Andersen] 
Ampay Tapaculo

Etymology: We take the opportunity to honor our friend and colleague Bret M. Whitney for his outstanding contributions to Neotropical ornithology over the past 3 decades. Bret’s keen eyes and ears, and his insightful attention to vocalizations and natural history, have given us a much greater understanding of variation and species limits in several challenging groups of tropical birds, and particularly in Scytalopus. The recommended English name refers to Bosque Ampay, the only protected area where the species occurs.

Niels K. Krabbe, Thomas S. Schulenberg, Peter A. Hosner, Kenneth V. Rosenberg, Tristan J. Davis, Gary H. Rosenberg, Daniel F. Lane, Michael J. Andersen, Mark B. Robbins, Carlos Daniel Cadena, Thomas Valqui, Jessie F. Salter, Andrew J. Spencer, Fernando Angulo and Jon Fjeldså. 2020. Untangling Cryptic Diversity in the High Andes: Revision of the Scytalopus [magellanicus] complex (Rhinocryptidae) in Peru reveals Three New Species. The Auk. ukaa003. DOI: 10.1093/auk/ukaa003 

RESUMEN: Las zonas montañosas tropicales se caracterizan por un alto grado de reemplazo de especies a través de gradientes altitudinales y de topografías complejas, lo cual se manifiesta en una alta concentración de diversidad aviar. En estos paisajes, particularmente en grupos aviares con morfología conservada y difíciles de observar, los límites entre especies aún requieren ser aclarados. Uno de estos linajes es el género Scytalopus, que reúne a algunas de las aves con morfología más conservada. Estudios enfocados en las diferencias en repertorio vocal y relaciones filogenéticas han conducido a una proliferación de descripciones de especies nuevas, muchas de las cuales son endémicas con distribuciones muy restringidas. Presentamos una revisión taxonómica e identificamos límites de especies entre poblaciones de Scytalopus de grandes elevaciones de los Andes peruanos. Empleamos un enfoque integrado que combina información de vocalizaciones, de secuencias de ADN mitocondrial y de caracteres del plumaje.

Los datos fueron obtenidos mediante nuestro trabajo de campo en los últimos 40 años, complementados con información de archivos de sonidos y especímenes de museo. Describimos tres nuevas especies endémicas de Perú. Dentro de las tres existe diferenciación genética, que en dos casos se asocia con variación geográfica sutil en plumaje y vocalizaciones. Documentamos que en una cuarta especie, Scytalopus schulenbergi, existe divergencia genética profunda y variación en plumaje a pesar de que las poblaciones son similares vocalmente en general. Además, proponemos que un taxón de otra región, Scytalopus opacus androstictus, se eleve al rango de especie, con base en un carácter vocal diagnóstico. Nuestros resultados demuestran que las exploraciones básicas y un trabajo descriptivo basado en fuentes de datos diversos sigue permitiendo identificar nuevas especies de aves, particularmente en ambientes tropicales.