Jaime García-Moreno

Congruent Avian Phylogenies Inferred from Mitochondrial and Nuclear DNA Sequences

Recent molecular studies addressing the phylogenetic relationships of avian orders have had conflicting results. While studies using nuclear DNA sequences tend to support traditional taxonomic views, also supported by morphological data [(paleognaths (galloanseres (all other birds)))], with songbirds forming a clade within Neoaves (all other birds), analyses with complete mtDNA genomes have resulted in topologies that place songbirds as one of the earliest-diverging avian lineages. Considering that over half of the extant bird species are songbirds, these different results have very different implications for our understanding of avian evolution. We analyzed data sets comprising nearly 4 kb of mitochondrial DNA (mtDNA) (complete 12S, ND1, ND2, and cytochrome b) plus 600 bp of the nuclear gene c-mos for 15 birds that were chosen to represent all major avian clades and to minimize potential long-branch attraction problems; we used a partition-specific maximum likelihood approach. Our results show congruence with respect to the ingroup among phylogenies obtained with mtDNA and the nuclear gene c-mos, separately or combined. The data sets support a traditional avian taxonomy, with paleognaths (ratites and tinamous) occupying a basal position and with songbirds more derived and forming a monophyletic group. We also show that, for mtDNA studies, turtles may be a better outgroup for birds than crocodilians because of their slower rate of sequence evolution.

Phylogeography of the Buarremon brush-finch complex (Aves, Emberizidae) in Mesoamerica

The Buarremon brush-finches represent a complex suite of populations distributed in the montane New World Tropics from Mexico south to South America. Traditional taxonomic arrangements have separated populations of this genus into three species, based on plumage variation, although plumage patterns are well known to exhibit homoplasy. We present a first detailed phylogeographic and phylogenetic study, focused on Mesoamerican populations, and signal the existence of strong differentiation among populations with a clear geographic structure. We find well differentiated clades for (1) the Sierra Madre Oriental and Sierra Madre del Sur in Oaxaca, (2) western Mexican populations, including the B. brunneinucha populations in the Sierra Madre del Sur and B. virenticeps, (3) Sierra Madre Oriental and Sierra de los Tuxtlas, (4) northern Central America, (5) southern Central America, (6) middle Central America, and (7) South America. We demonstrate a lack of concordance with plumage patterns, and argue for several additional species to be recognized in the complex.

Phylogeography and population genetics of the Amethyst-throated Hummingbird (Lampornis amethystinus)

We analyzed mitochondrial DNA sequence variation across 69 Amethyst-throated Hummingbirds (Lampornis amethystinus), comparing with samples of related taxa. Although this group shows discrete phenotypic variation in throat color among populations in Oaxaca and Guerrero (Mexico), the only phylogeographic structure observed was between phenotypically similar populations north and south of the Isthmus of Tehuantepec. As such, it appears that throat color variation is of recent origin and likely based only on minor genetic differences.

The importance of birds for conservation in the Neotropical region

Habitat loss remains the major threat to birds in the Neotropics, although there are several additional specific threats, for example trade, nest parasitism, invasives on islands, and for seabirds, bycatch. Capacity building also remains a key issue for conservation in the area. Nevertheless, the region has benefited by a surge in research, with an increase in Neotropical avian studies over the last decade, many of them incorporating modern techniques for analyzing a variety of data, for example vocalization and molecular data. These studies have improved our general understanding of the taxonomic status of several forms, and their ecology and conservation needs, and the bird-watching community has become an important force that can be mobilized to gather information and to support conservation efforts. But birds themselves are playing now a key role in the development of conservation strategies in the region. The important bird areas (IBAs) promoted by BirdLife are now a key component in our strategy for defining key biodiversity areas (KBAs), by means of which Conservation International is attempting to broaden the taxonomic spectrum of the IBA concept. Migratory birds and those with large home range are becoming important elements in our strategy as we try to move from IBAs and KBAs to large-scale biodiversity corridors.

Diversification in the Andes: the Atlapetes brush-finches

With nearly 30 species, the Atlapetes brush‐finches are one of the most species‐rich genera in the New World sparrows (Passerellidae). Atlapetes is mainly distributed in highland forests from Mexico to north‐western Argentina, with a few taxa in the foothills (<1000 m). Species diversity is highest in South America, because of high rates of local replacement but few cases of local co‐occurrence, creating a mosaic of forms with different plumage colours. With the purpose of understanding phylogenetic and environmental determinants of trait evolution, we reconstructed a molecular phylogeny based on full ND2 mtDNA sequences, with focus on the core group of Andean Atlapetes species and related outgroups. Phylogenetic relationships revealed that most Andean species are closely related to a geographical neighbour, although these neighbours may often be phenotypically quite different, with yellow‐plumaged species sister to grey‐plumaged taxa. Biogeographic analyses suggest Mesoamerica as the area of origin for Atlapetes, which dispersed through the Panama Isthmus to the eastern Andean slope, then the western Andes and finally the southern Andes. Diversification in the genus was apparently influenced by the glacial cycles that affected the distribution of montane forests in the Neotropics, particularly during the last million years. Phenotypic plumage changes may be associated with ecological conditions, with black dorsum in the wettest areas and a pale dorsum in a group of closely related species in dry environments on the Pacific slope. Local sympatry and ecological segregation presumably does not lead to increased divergence in plumage signals or song.

Phylogeny of woodcreepers of the genus Lepidocolaptes (Aves, Furnariidae), a widespread Neotropical taxon

Arbeláez‐Cortés, E., Navarro‐Sigüenza, A. G. & García‐Moreno J. (2012). Phylogeny of woodcreepers of the genus Lepidocolaptes (Aves, Furnariidae), a widespread Neotropical taxon. —Zoologica Scripta, 41, 363–373.