The evolution of sexually dimorphic traits in ecological gradients: an interplay between natural and sexual selection in hummingbirds.

Traits that exhibit differences between the sexes have been of special interest in the study of phenotypic evolution. Classic hypotheses explain sexually dimorphic traits via intra-sexual competition and mate selection, yet natural selection may also act differentially on the sexes to produce dimorphism. Natural selection can act either through physiological and ecological constraints on one of the sexes, or by modulating the strength of sexual/social selection. This predicts an association between the degree of dimorphism and variation in ecological environments. Here, we characterize the variation in hummingbird dimorphism across ecological gradients using rich databases of morphology, colouration and song. We show that morphological dimorphism decreases with elevation in the understorey and increases with elevation in mixed habitats, that dichromatism increases at high altitudes in open and mixed habitats, and that song is less complex in mixed habitats. Our results are consistent with flight constraints, lower predation pressure at high elevations and with habitat effects on song transmission. We also show that dichromatism and song complexity are positively associated, while tail dimorphism and song complexity are negatively associated. Our results suggest that key ecological factors shape sexually dimorphic traits, and that different communication modalities do not always evolve in tandem.

Taxonomic, phylogenetic, and trait Beta diversity in South American hummingbirds.

Comparison of the taxonomic, phylogenetic, and trait dimensions of beta diversity may uncover the mechanisms that generate and maintain biodiversity, such as geographic isolation, environmental filtering, and convergent adaptation. We developed an approach to predict the relationship between environmental and geographic distance and the dimensions of beta diversity. We tested these predictions using hummingbird assemblages in the northern Andes. We expected taxonomic beta diversity to result from recent geographic barriers limiting dispersal, and we found that cost distance, which includes barriers, was a better predictor than Euclidean distance. We expected phylogenetic beta diversity to result from historical connectivity and found that differences in elevation were the best predictors of phylogenetic beta diversity. We expected high trait beta diversity to result from local adaptation to differing environments and found that differences in elevation were correlated with trait beta diversity. When combining beta diversity dimensions, we observe that high beta diversity in all dimensions results from adaption to different environments between isolated assemblages. Comparisons with high taxonomic, low phylogenetic, and low trait beta diversity occurred among lowland assemblages separated by the Andes, suggesting that geographic barriers have recently isolated lineages in similar environments. We provide insight into mechanisms governing hummingbird biodiversity patterns and provide a framework that is broadly applicable to other taxonomic groups.

[Frugivory and seed dispersal Oenocarpus bataua palm (Arecaceae) in a forest from the Colombian Andes]. / Frugivoría y dispersión de semillas de la palma Oenocarpus bataua (Arecaceae) en un bosque de los Andes colombianos.

Seed dispersal is a key process that determines the spatial structure and dynamics of populations of plants, establishes the potential area of recruitment and in this way, the basis for subsequent processes such as predation, germination, competition and growth. The purpose of this research was to identify the guild of frugivores of the Oenocapus bataua palm in fragments of Andean forest, determine the effective dispersers and relate the spatial distribution of palm populations with the dispersion of seeds. To this end, between August 2005-June 2006, observations of the removal of fruits from eight clusters were done, and counting of consumption of fruits beneath 78 palms with mature fruits was undertaken; focal observations of 13 individuals during 90 hours; registration of frugivory with photographic traps during 165 days/nights for a total of 195 photographs and 144 consumption events; experiments with dispersion using 751 perforated fruits/seeds attached to strings and finally, plots to determine spatial distribution all were carried out. In the study area at least five species of mammals ate, dispersed, buried (Sciurus granatensis, Microsciurus mimulus, Dasyprocta punctata y Proechimys sp.), cover (Marmosa robinsoni) and carried the fruits of O. bataua off to caves (Marmosa robinsoni y Proechimys sp.) without damaging the seed. A 21.7% of the fruits were dispersed, 13.2 gnawed or peeled, 5.6% covered, buried and carried to caves. The average distance of removal of seeds and fruits was 3.1m although in a lesser proportion, dispersion events of >50m were recorded. The abundant production of fruits, their size and weight, their intense removal by frugivores, the short dispersion distances, the absence of large size frugivores (reduced by hunting and fragmentation), that might perform long-distance dispersion, and the increase of rodents, especially squirrels, that strongly pressure the fruit resource, generate a spatially restricted seed rain of seeds responsible for the aggregate patterns of distribution of seeds, seedlings and subsequently of juveniles and sub-adults. However the short time and high percentage of seed germination and the robustness of seeds and seedlings give O. bataua the capacity to survive in dense aggregations. Therefore, despite the limitations on dispersion, this is a dominant species in the study area. Populations of O. bataua have been reduced by intense exploitation and by the transformation and reduction of their natural habitat. The over-exploitation of the fruits or the juvenile phases of this palm can affect the age structure and population dynamics. Therefore, the management and exploitation of this palm in the future will depend to large degree on the conservation of forest habitats.

The generic nomenclature of the emeralds, Trochilini (Apodiformes: Trochilidae): two replacement generic names required.

Many genus-level changes to the classification of Trochilini were enacted in Stiles et al. (2017b). We have since found that two further genera therein emended each require replacement names. The first of these requiring a replacement name is Uranomitra Reichenbach, 1854 [March], which is herewith interpreted as an additional synonym of Saucerottia Bonaparte, 1850, along with its junior synonym Cyanomyia Bonaparte, 1854a [May]. We show that both must have the same type species, as originally designated, Trochilus quadricolor Vieillot, 1822 = Ornismya cyanocephala Lesson, 1829. The second case in which a replacement name is required is Leucolia Mulsant E. Verreaux, 1866, herewith interpreted as an additional synonym of Leucippus Bonaparte, 1850, with the same type species, Trochilus fallax Bourcier, 1843. We herein propose replacement names for both Uranomitra and Leucolia.

A new subspecies in the Turdus nudigenis complex (Aves: Turdidae) from the Cauca River valley of Colombia.

The taxonomy of the T. nudigenis complex has historically been challenging due to the uniformity in plumage among taxa, poorly known vocal variation, and allopatric distributions. Recent phylogenetic analyses have contributed to understanding relationships within the genus; however, much remains to be learned about the extent of phenotypic and genetic differentiation within taxa and its implications in species limits. Here, we analyze the taxonomic status of an enigmatic member of the T. nudigenis complex restricted to the Cauca River valley of Colombia. Our phylogenetic analyses suggest that the Cauca valley population is genetically distinctive from other members of the complex, although its sister relationships with respect to T. grayi and T. nudigenis could not be fully resolved due to paraphyly in the group. Based on similarity of plumage, calls, and biogeographic proximity we tentatively treat this taxon as a new subspecies of T. grayi. Populations from the northern Caribbean T. grayi casius/incomptus and the new taxon inhabit similar environmental conditions, being apparently isolated by the humid Nech lowlands. A formal analysis of vocalizations coupled with a more robust genomic dataset are needed to resolve the systematic affinities and taxonomic status of several members of the T. nudigenis complex.

The generic nomenclature of the Trochilini: a correction.

Because the generic name Elliotia proposed by us (Stiles et al. 2017a) was found to be preoccupied, we herein rename this genus, including a detailed diagnosis; the generic circumscription and type species remain unchanged. This change does not affect the generic reorganization of the Trochilini presented by Stiles et al. (2017a).

Distribution and status of Turdus thrushes in white-sand areas of eastern Colombia, with a new subspecies of T. leucomelas.

White-sand areas in the Colombian Amazon harbor many endemic and specialist species that are relatively little studied with respect to their ecology, distribution and zoogeographic affinities, for example Turdus thrushes. A recent expedition to the Serranía de Chiribiquete, a mountain range of Guianan origin in the Colombian Amazon, resulted in the discovery of an enigmatic Turdus thrush restricted to white-sand vegetation. Molecular phylogenetic analyses of the ND2 gene revealed that this population is genetically similar to T. leucomelas albiventer, from which it differs in its smaller size and darker, duller plumage. Therefore, we here describe this population as a new subspecies of T. leucomelas. Furthermore, our inspection of specimens of Turdus taxa from eastern Colombia revealed the existence of sympatry between T. ignobilis debilis and T. i. arthuri at two sites. Based on this evidence and previously documented genetic and phenotypic differences, we recognize T. arthuri as a distinct biological species. We analyze distributions and measurements of functional traits among four thrush taxa of eastern Colombia.

Phylogenetic relationships of the Mangrove Hummingbird, "Amazilia" boucardi (Apodiformes: Trochilidae) of Costa Rica / Relaciones filogenéticas del Colibrí manglero "Amazilia" boucardi (Apodiformes: Trochilidae) de Costa Rica

Abstract Introduction: A recent revision of the generic classification of the Trochilidae based on DNA sequences revealed many inconsistencies with the current generic classification, largely based on plumage characters subject to homoplasy, especially in the Trochilini, the largest tribe. A thorough generic reorganization brought the classification into accord with the phylogeny, but due to lack of genetic data, two species remained unclassified. One of these was the Mangrove Hummingbird, "Amazilia" boucardi, endemic to Costa Rica and included in the IUCN red list of threatened species. Objective: To obtain molecular evidence to clarify the generic relationships of "A." boucardi. Methods: We isolated DNA from tissues of this species and amplified 4 nuclear and 4 mitochondrial fragments and compared these with homologous fragments from 56 species in the Trochilini, constructing phylogenetic trees with maximum likelihood and Bayesian methods. Results: Our phylogenetic analyses confirmed the placement of boucardi in the Trochilini and definitely excluded it from Amazilia but placed it with high confidence in the genus Chrysuronia Bonaparte, 1850, within which its closest relative is C. coeruleogularis, which also inhabits mangroves. Conclusions: Our genetic data based on nuclear and mitochondrial regions clearly indicate the relationship of A. boucardi and L. coeruleogularis. Moreover, it is also supported by their habitat distribution in the mangroves of the Pacific coast of Costa Rica and Western Panama. Therefore, we suggested to exclude A. boucardi as "incertae sedis".

Resumen Introducción: Una revisión reciente de la clasificación de la familia Trochilidae con base en secuencias de ADN demostró muchas incongruencias con la clasificación genérica previa, que había sido hecho con base en caracteres del plumaje muy sujetos a homoplasia, especialmente en la tribu más grande, Trochillini. Una reorganización de los géneros logró llevar su clasificación genérica a la concordancia con la filogenia, pero debido a la ausencia de datos genéticos, dos especies permanecieron sin clasificar. Una de estas fue el colibrí de manglar Amazilia boucardi, una especie endémica de Costa Rica, considerada como amenazada en la lista roja de la UICN. Objetivo: Obtener evidencia molecular para esclarecer las relaciones genéricas de A. boucardi. Métodos: Se aisló ADN de tejidos de esta especie y se amplificaron 4 fragmentos de ADN del núcleo y 5 de la mitocondria, y se compararon con fragmentos homólogos de 56 especies en la tribu Trochillini, generando árboles filogenéticos con métodos de máxima verosimilitud y bayesiano. Resultados: Los análisis filogénticos obtenidos confirmaron la ubicación de boucardi en Trochilini y definitivamente la excluyó del género Amazilia, pero la ubicó con un alto grado de confianza en el género Chrysuronia Bonaparte, 1850, dentro los cuales su pariente más cercano es C. coeruleogularis, que también habita manglares. Conclusiones: Nuestros datos genéticos basados en regiones nucleares y mitocondriales indican claramente la relación entre A. boucardi and L. coeruleogularis. Es más, lo anterior se sustenta por su distribución en los manglares de la costa Pacífica de Costa Rica y oeste de Panamá. Por lo tanto, sugerimos excluir a A. boucardi como "incertae sedis".

The generic classification of the Trochilini (Aves: Trochilidae): Reconciling taxonomy with phylogeny.

The generic nomenclature of the hummingbirds is unusually complicated. McGuire et al.'s (2014) recent phylogeny of the Trochilidae based on DNA sequence data has greatly clarified relationships within the family but conflicts strongly with the traditional classification of the family at the genus level, especially that of the largest and most recently derived clade, the Trochilini or "emeralds". We recently presented a historical review of this classification and the generic modifications required by the Code of the International Commission on Zoological Nomenclature. Herein we present a revised generic classification of the Trochilini based upon McGuire et al.'s genetic data, while producing diagnosable generic groupings and preserving nomenclatural stability insofar as possible. However, this generic rearrangement has necessitated the resurrection of nine generic names currently considered synonyms, the synonymization of seven currently recognized genera and the creation of one new genus. The generic changes we recommend to the classification are drastic, and we summarize these in tabular form in comparison with the three most recent classifications of the Trochilini. Where appropriate, we outline alternatives to our proposed arrangement. The classification treats 110 species in 35 genera, including two species that remain unplaced for lack of genetic samples.

A brief history of the generic classification of the Trochilini (Aves: Trochilidae): the chaos of the past and problems to be resolved.

The generic classification of the Trochilidae is unusually complicated because early authors, faced with a deluge of specimens with little or no data, often based species and genus names on superficial plumage characters derived from figured plates of varying artistic quality and reproduction. Working independently and with little knowledge of species distributions and with the fixation of type species for genera inconsistent or ignored, these authors produced a bewildering array of generic synonyms. The generic nomenclature of the largest and most recently derived clade of hummingbirds, the tribe Trochilini or "emeralds", presents an unusually tangled web. Here we review the history of hummingbird generic nomenclature from Linnaeus to the present, giving detailed attention to two generic names that epitomize this confusion: Amazilia (the variety of spellings, supposed type species and circumscriptions makes for an especially complicated tangle) and Leucippus (for which nearly every successive author has advocated a different circumscription). Through application of the International Code for Zoological Nomenclature, this review lays the foundation for a revision of the generic nomenclature of the emeralds to bring it into conformity with recent genetic studies elucidating the phylogeny of this clade.

Geographic variation and phylogenetic relationships of Myiopagis olallai (Aves: Passeriformes; Tyrannidae), with the description of two new taxa from the Northern Andes.

Geographic variation in vocalizations, morphology and plumage patterns in New World flycatchers is little understood, particularly in rare species with disjunct distributions. We discovered a distinct new flycatcher of the genus Myiopagis from cloud forests of the northern Central Andes in Antioquia, Colombia. Comparisons of vocalizations and external morphology, and molecular phylogenetic analyses, demonstrate that the "Antioquia Myiopagis" is a unique lineage of the M. caniceps-olallai group. We show that three specimens collected in 1940-1951 from cloud forests of Serranía de Perijá in Venezuela, and traditionally assigned to M. caniceps, represent another distinct taxon that is closer to the "Antioquia Myiopagis" and M. olallai. Both new taxa, from Antioquia and Perijá, are described as subspecies of M. olallai. We present a phylogenetic hypothesis for the M. caniceps-olallai group, in which M. olallai and the "Antioquia Myiopagis" are phylogenetically nested within the polytypic M. caniceps, which consists of at least four distinct lineages, indicating that species diversity in this group could be underestimated.