Geology topics

Andres M Cuervo

Publications and source records attributed to Andres M Cuervo.

3 recordsLinked to original sources

USGS2020

Conservative plumage masks extraordinary phylogenetic diversity in the Grallaria rufula (Rufous Antpitta) complex of the humid Andes

The Grallaria rufula complex is currently considered to consist of 2 species, G. rufula (Rufous Antpitta) and G. blakei (Chestnut Antpitta). However, it has been suggested that the complex, populations of which occur in humid montane forests from Venezuela to Bolivia, comprises a suite of vocally distinct yet morphologically cryptic species. We sequenced nuclear and mitochondrial DNA for 80 individuals from across the distribution of the complex to determine the extent of genetic variation between and within described taxa. Our results revealed 18 geographically coherent clades separated by substantial genetic divergence: 14 within rufula, 3 within blakei, and 1 corresponding to G. rufocinerea (Bicolored Antpitta), a species with distinctive plumage found to be nested within the complex. Neither G. rufula nor G. blakei as presently defined was monophyletic. Although 6 of the 7 recognized subspecies of G. rufula were monophyletic, several subspecies contained substantial genetic differentiation. Genetic variation was largely partitioned across recognized geographic barriers, especially across deep river valleys in Peru and Colombia. Coalescent modeling identified 17 of the 18 clades as significantly differentiated lineages, whereas analyses of vocalizations delineated 16 biological species within the complex. The G. rufula complex seems unusually diverse even among birds of the humid Andes, a prime location for cryptic speciation; however, the extent to which other dispersal-limited Andean species groups exhibit similar degrees of cryptic differentiation awaits further study.

Auk↗

USGS2020

Taxonomic evaluation of the Grallaria rufula (Rufous Antpitta) complex (Aves: Passeriformes: Grallariidae) distinguishes sixteen species

Populations in the Rufous Antpitta ( Grallaria rufula ) complex occupy humid montane forests of the Andes from northern Colombia and adjacent Venezuela to central Bolivia. Their tawny to cinnamon-colored plumages are generally uniform, featuring subtle variation in hue and saturation across this range. In contrast to their conservative plumage, substantial vocal differences occur among geographically isolated or parapatric populations. Working within the framework of a comprehensive molecular phylogeny, we reexamined species limits in the G. rufula complex, basing taxonomic recommendations on diagnostic differences in vocalizations and considering identifiable differences in plumage where pertinent. We identified 16 populations for species designation, including seven populations previously described as subspecies and, remarkably, six new species described herein. Within one of these species, we identified less robust vocal differences between populations that we designate as subspecies. Geographic variation exists within another species, but its critical evaluation requires additional material. Taxonomic revisions of groups consisting of cryptic species, like the Grallaria rufula complex, are imperative for their conservation. Rather than widespread species as currently defined, these complexes can comprise many range-restricted taxa at higher risk of extinction given the continuing human pressures on their habitats.

Zootaxa↗

USGS2020

The evolution of a tropical biodiversity hotspot

The role of the environment in the origin of new species has long been debated. Harvey et al. examined the evolutionary history and species diversity of suboscine birds in the tropics (see the Perspective by Morlon). Contrary to expectations that the tropics have higher rates of speciation, the authors observed that higher and more constant speciation rates occur in harsh environments relative to the tropics. Thus, for this group of birds, diversification in temperate to Arctic regions followed by the movement and retention of species in the tropics results in their higher local levels of species diversity.

Science↗