Publications

2017

The role of the environment on the genetic divergence between two Boa imperator lineages

Abstract: A fundamental problem in evolutionary biology has been understanding the role of environmental factors in the process of genetic diversification. Our main goal was to define the ecological niches of two Boa imperator lineages, in order to assess if environmental drivers could be associated with the divergence and genetic variation between them. We quantified the environmental niches at two evolutionary and geographical scales: regional-historical (lineages) and local-ecological (individuals within lineages).

2016

Long-distance dispersal and inter-island colonization across the western Malagasy Region explain diversification in brush-warblers (Passeriformes: Nesillas)

Abstract: The present study examines the colonization history and phylogeography of the brush-warblers (Nesillas), a genus of passerines endemic to islands of the western Indian Ocean (Madagascar, Comoros, and Aldabra Atoll). The phylogeny of all recognized Nesillas taxa was reconstructed employing Bayesian phylogenetic methods and divergence times were estimated using a range of substitution rates and clock assumptions. Spatiotemporal patterns of population expansion were inferred and niches of different lineages were compared using ecological niche modelling. Our results indicate that taxa endemic to the Comoros are paraphyletic and that the two endemic species on Madagascar (Nesillas typica and Nesillas lantzii) are not sister taxa.

Process-Based Species Pools Reveal the Hidden Signature of Biotic Interactions Amid the Influence of Temperature Filtering

Abstract: A persistent challenge in ecology is to tease apart the influence of multiple processes acting simultaneously and interacting in complex ways to shape the structure of species assemblages. We implement a heuristic approach that relies on explicitly defining species pools and permits assessment of the relative influence of the main processes thought to shape assemblage structure: environmental filtering, dispersal limitations, and biotic interactions. We illustrate our approach using data on the assemblage composition and geographic distribution of hummingbirds, a comprehensive phylogeny and morphological traits. The implementation of several process-based species pool definitions in null models ...


2015

La Ecología Funcional como aproximación al estudio, manejo y conservación de la biodiversidad: protocolos y aplicaciones

Introduccion: La idea de que la diversidad funcional está más relacionada con procesos ecosistémicos que la diversidad de especies tiene serias consecuencias sobre la toma de datos y decisiones en relación a la conservación de la biodiversidad (Díaz y Cabido 2001, Flynn et al. 2009, Devoto et al. 2012). Es prioritario identificar los rasgos que determinan cómo las especies responden a cambios en el ambiente –rasgos de respuesta sensu Luck et al. (2012) y cómo las especies contribuyen o tienen efectos sobre procesos a nivel ecosistémico –rasgos de efecto sensu Luck et al. (2012). Los rasgos funcionales son caracteres morfológicos, fisiológicos y de historia de vida que afectan el desempeño biológico de los individuos, son escalables a otros niveles de organización biológica como poblaciones y comunidades, y pueden estar involucrados en procesos a nivel ecosistémico como la regeneración de sistemas perturbados a través de la dispersión de semillas, el control de plagas y la polinización, entre otros ...

2014

Node-based analysis of species distributions

Abstract: 1. The integration of species distributions and evolutionary relationships is one of the most rapidly moving research fields today and has led to considerable advances in our understanding of the processes underlying biogeographical patterns. Here, we develop a set of metrics, the specific overrepresentation score (SOS) and the geographic node divergence (GND) score, which together combine ecological and evolutionary patterns into a single framework and avoids many of the problems that characterize community phylogenetic methods in current use.

2. This approach goes through each node in the phylogeny and compares the distributions of descendant clades to a null model. The method employs a balanced null model, is independent of phylogeny size, and allows an intuitive visualization of the results.

3. We demonstrate how this novel implementation can be used to generate hypotheses for biogeographical pat- terns with case studies on two groups with well-described biogeographical histories: a local-scale community data set of hummingbirds in the North Andes, and a large-scale data set of the distribution of all species of New World flycatchers. The node-based analysis of these two groups generates a set of intuitively interpretable patterns that are consistent with current biogeographical knowledge.

4. Importantly, the results are statistically tractable, opening many possibilities for their use in analyses of evolu- tionary, historical and spatial patterns of species diversity. The method is implemented as an upcoming R pack- age nodiv, which makes it accessible and easy to use.

Avifauna de los hábitats de la desembocadura del Río Atrato (Turbo, Antioquia)

Abstract: Caracterizamos la distribución espacial de la avifauna en la desembocadura Coquitos del río Atrato para evaluar si la riqueza, dominancia, y distribución de abundancias de aves estaban asociadas a tres hábitats: el manglar, la ribera de río y el plano lodoso. Para cuantificar si cambios en la composición de aves estaban relacionados con cambios de hábitat se estimaron índices de betadiversidad entre y dentro de hábitats y en relación a lo esperado bajo un modelo nulo. De manera cualitativa realizamos un Análisis de Componentes Principales (ACP) para visualizar las relaciones entre sitios con base en su composición de especies. Finalmente se evaluò si era posible asignar un listado de especies avistadas durante un punto de conteo a un hábitat particular mediante un análisis discriminante linear con validación cruzada (ALD). Encontramos que los tres hábitats evaluados poseen una composición y diversidad de aves diferentes. El manglar fue el hábitat con menor riqueza observada y estimada, menor diversidad y mayor dominancia, mientras que la ribera de río presentó mayor riqueza, diversidad y equitatividad y el plano lodoso la mayor riqueza observada y estimada. La betadiversidad fue significativamente mayor entre hábitats que dentro de hábitats....

Birds of Antioquia: Georeferenced database of specimens from the Colección de Ciencias Naturales del Museo Universitario de la Universidad de Antioquia (MUA)

Abstract: The department of Antioquia, Colombia, lies in the northwestern corner of South America and provides a biogeographical link among divergent faunas, including Caribbean, Andean, Pacific and Amazonian. Information about the distribution of biodiversity in this area is of relevance for academic, practical and social purposes. This data paper describes the data set containing all bird specimens deposited in the Colección de Ciencias Naturales del Museo Universitario de la Universidad de Antioquia (MUA). We curated all the in- formation associated with the bird specimens, including the georeferences and taxonomy, and published the database through the Global Biodiversity Information Facility network. During this process we checked the species identification and existing georeferences and completed the information when possible. The collection holds 663 bird specimens collected between 1940 and 2011. Even though most specimens are from Antioquia (70%), the collection includes material from several other departments and one specimen from the United States. The collection holds specimens from three endemic and endangered species (Coeligena orina, Diglossa gloriossisima, and Hypopirrhus pyrohipogaster), and includes localities poorly represented in other collections. The information contained in the collection has been used for biodiversity modeling, conservation planning and management, and we expect to further facilitate these activities by making it publicly available.

The origin and maintenance of montane diversity: integrating evolutionary and ecological processes

Abstract: Determining how ecological and evolutionary processes produce spatial variation in local species richness remains an unresolved challenge. Using mountains as a model system, we outline an integrative research approach to evaluate the influence of ecological and evolutionary mechanisms on the generation and maintenance of patterns of species richness along and among elevational gradients. Biodiversity scientists interested in patterns of species richness typically start by documenting patterns of species richness at regional and local scales, and based on their knowledge of the taxon, and the environmental and historical characteristics of a mountain region, they then ask whether diversity–environment relationships, if they exist, are explained mostly by ecological or evolutionary hypotheses. The final step, and perhaps most challenging one, is to tease apart the relative influence of ecological and evolutionary mechanisms. We propose that elucidating the relative influence of ecological and evolutionary mechanisms can be achieved by taking advantage of the replicated settings afforded by mountains, combined with targeted experiments along elevational gradients. This approach will not only identify potential mechanisms that drive patterns of species richness, but also allow scientists to generate more robust hypotheses about which factors generate and maintain local diversity...

Taxonomic, Phylogenetic, and Trait Beta Diversity in South American Hummingbirds

Abstract: 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 adaptation 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....

2013

Tracking climate change in a dispersal-limited species: reduced spatial and genetic connectivity in a montane salamander

Abstract: Tropical montane taxa are often locally adapted to very specific climatic conditions, contributing to their lower dispersal potential across complex landscapes. Climate and landscape features in montane regions affect population genetic structure in predictable ways, yet few empirical studies quantify the effects of both factors in shaping genetic structure of montane-adapted taxa. Here, we considered temporal and spatial variability in climate to explain contemporary genetic differentiation between popula- tions of the montane salamander, Pseudoeurycea leprosa. Specifically, we used ecologi- cal niche modelling (ENM) and measured spatial connectivity and gene flow (using both mtDNA and microsatellite markers) across extant populations of P. leprosa in the Trans-Mexican Volcanic Belt (TVB). Our results indicate significant spatial and genetic isolation among populations, but we cannot distinguish between isolation by distance over time or current landscape barriers as mechanisms shaping population genetic divergences. ...

Extending ecological niche models to the past 120 000 years corroborates the lack of strong phylogeographic structure in the Crested Drongo (Dicrurus forficatus forficatus) on Madagascar

Abstract: We conduct a phylogeographic study of the Crested Drongo (Dicrurus forficatus forficatus), a broadly distributed bird species on Madagascar. We first determined the demographic and spatial pattern inferred from mitochondrial and nuclear data, and then compared these results with predictions from a present to 0.120-Myr-old reconstruction of the spatial dynamics of the range of D. f. forficatus on Madagascar, enabling putative areas of stability (lineage persistence) to be detected. Weak genetic structure along an east–west pattern and comparatively low genetic diversity were recovered, with strong evidence of population expansion found at all ten loci sampled. The palaeoclimatic distribution models over the past 0.120 Myr suggest the presence of extensive areas of suitable climate in the east and west for the species since its colonization of Madagascar, a result in strong concordance with the spatial and genetic signal derived from our multilocus data set.

2012

Untangling the influence of ecological and evolutionary factors on trait variation across hummingbird assemblages

Abstract: Phylogenetic community ecology combines phylogenetic hypotheses with local species composition and functional-trait information to evaluate historical and contemporary mechanisms influencing local assemblage structure. Most studies assume that, if functional traits are conserved, then patterns of trait variation should match patterns of phylogenetic structure within local assemblages. Here we evaluated if we could predict trait structure by assuming that environmental filtering or biotic interactions work primarily on phylogenetically conserved functional traits. We investigated patterns of phylogenetic assemblage structure and functional-trait variation in bill length, wing length, and body mass in 236 hummingbird assemblages (126 species) across two major gradients in northern South America: elevation and precipitation...

The role of competition in structuring tropical bird communities

Abstract: Despite several decades of intense scrutiny, the role of competition as a force structuring ecolog- ical communities remains controversial. Here we summarize a symposium focused on examining the effect of interspecific competition on the distribution and abundance of bird species in tropical ecosystems, where biotic interactions are likely to be most intense because of high diversity in stable environments. We outline a series of independent studies, each tackling long-standing questions by utilizing or combining modern tech- niques and resources that were largely unavailable in previous decades. These include long-term datasets tracking changes in abundance and behavior, experimental tests of behaviorally-mediated segregation, ap- plication of intensive territory mapping, stable isotopes, and remotely sensed data to measure habitat niches, and community phylogenetic methods for assessing patterns of coexistence within larger clades. Collectively, these approaches offer rich potential for evaluating the strength of competition between interacting species and clarifying its effect on the structure of communities at local and regional scales.

Sensitivity of Metrics of Phylogenetic Structure to Scale, Source of Data and Species Pool of Hummingbird Assemblages along Elevational Gradients

Abstract: Patterns of phylogenetic structure of assemblages are increasingly used to gain insight into the ecological and evolutionary processes involved in the assembly of co-occurring species. Metrics of phylogenetic structure can be sensitive to scaling issues and data availability. Here we empirically assess the sensitivity of four metrics of phylogenetic structure of assemblages to changes in (i) the source of data, (ii) the spatial grain at which assemblages are defined, and (iii) the definition of species pools using hummingbird (Trochilidae) assemblages along an elevational gradient in Colombia. We also discuss some of the implications in terms of the potential mechanisms driving these patterns. To explore...

2011

Latitude, elevational climatic zonation and speciation in New World vertebrates

Abstract: Many biodiversity hotspots are located in montane regions, especially in the tropics. A possible explanation for this pattern is that the narrow thermal tolerances of tropical species and greater climatic stratification of tropical mountains create more opportunities for climate-associated parapatric or allopatric speciation in the tropics relative to the temperate zone. However, it is unclear whether...

Contrasting patterns of phylogenetic assemblage structure along the elevational gradient for major hummingbird clades

Abstract: We evaluated the hypothesis that, given niche conservatism, relatedness of co-occurring hummingbird species of a given clade will increase at greater distances from the elevation where it originated. We also used prior knowledge of flight biomechanics and feeding specialization of hummingbird species (family Trochilidae) to evaluate which environmental...

The role of climate, habitat, and species co-occurrence as drivers of change in small mammal distributions over the past century

Abstract: Species distribution models are commonly used to predict species responses to climate change. However, their usefulness in conservation planning and policy is controversial because they are difficult to validate across time and space. Here we capitalize on small mammal surveys repeated over a century in Yosemite National Park, USA, to assess accuracy of...

2010

Incorporating Clade Identity in Analyses of Phylogenetic Community Structure: An Example with Hummingbirds

Abstract: An important challenge in community ecology is to determine how processes occurring at multiple spatial, temporal, and phylogenetic scales influence the structure of local communities. While indexes of phylogenetic structure, which measure how related species are in a community, provide insight into the processes that shape species coexistence, they fail to pinpoint the...

Patterns of persistence and isolation indicate resilience to climate change in montane rainforest lizards

Abstract: Globally, montane tropical diversity is characterized by extraordinary local endemism that is not readily explained by current environmental variables, indicating a strong imprint of history. Montane species often exist as isolated populations under current climatic conditions and may have remained isolated throughout recent climatic cycles, leading to substantial genetic and...

Distribution and conservation of Grallaria and Grallaricula antpittas (Grallariidae) in Ecuador

Abstract: The current ranges of many tropical species of conservation concern are poorly known, yet this information is critical for assessing their conservation status against the IUCN Red List criteria and implementing species-level management. Antpittas in the genera Grallaria and Grallaricula are elusive, ground-foraging insectivores, highly susceptible to a range of threats. For these genera, we combine environmental niche modelling with expert knowledge in order to predict species’...

Color evolution in the hummingbird genus Coeligena

Abstract: The remarkable diversity of coloration and species present in hummingbirds has been considered the result of sexual selection. I evaluate if color differences among species in the genus Coeligena are consistent with expectations from sexual selection theory. If sexual selection on color is important for speciation, closely related species should be markedly different in the colors of feather patches associated with aggression and breeding. I evaluate this prediction through a statistical assessment of the phylogenetic signal of colors from five feather patches: crown, gorget, belly, upper back, and rump. The first two are associated with aggressive and courtship displays and are expected to be under sexual selection, whereas the others are not.

2009

Phylogenetic structure in tropical hummingbird communities

Abstract: How biotic interactions, current and historical environment, and biogeographic barriers determine community structure is a fundamental question in ecology and evolution, especially in diverse tropical regions. To evaluate patterns of local and regional diversity, we quantified the phylogenetic composition of 189 hummingbird communities in Ecuador. We assessed how species and phylogenetic composition changed along environmental gradients and across biogeographic barriers. We show that...

Molecular phylogenetics of the hummingbird genus Coeligena

Abstract: Advances in the understanding of biological radiations along tropical mountains depend on the knowledge of phylogenetic relationships among species. Here we present a species-level molecular phylogeny based on a multilocus dataset for the Andean hummingbird genus Coeligena. We compare this phylogeny to previous hypotheses of evolutionary relationships and use it as a framework to understand patterns in the evolution of sexual dichromatism and in the biogeography of speciation within the Andes. Previous phylogenetic hypotheses based mostly on similarities in coloration conflicted with our molecular phylogeny, emphasizing the unreliability of color characters for phylogenetic inference...

2008

Impact of a century of climate change on small-mammal communities in Yosemite National Park, USA

Abstract: We provide a century-scale view of small-mammal responses to global warming, without confounding effects of land-use change, by repeating Grinnell’s early–20th century survey across a 3000-meter-elevation gradient that spans Yosemite National Park, California, USA. Using occupancy modeling to control for variation in detectability, we show substantial (~500 meters on average) upward changes in elevational limits for half of 28 species monitored, consistent with the observed ~3°C...

Variability in 20th century climate change reconstructions and its consequences for predicting geographic responses of California mammals

Abstract: Empirical species distribution models are widely used to predict the effects of climate change on biodiversity distribution but rely on multiple assumptions about the certainty of the locality and climate data. Here, we assess the effect of historical climate data variability when forecasting geographic responses of California mammals to 20th...

2006

Seguir colectando aves en Colombia: Un llamado a fortalecer las colecciones ornitológicas

Abstract: El origen de la ornitología y su desarrollo reciente están cimentados en las colecciones científi cas de aves (Parkes 1963, Remsen 1995, Peterson et al. 1998, Winker 2004,2005). El estudio de especímenes de aves ha permitido la consolidación de conceptos biológicos fundamentales en áreas tan variadas como biodiversidad, evolución, ecología, genética y conservación ...

2005

Very high resolution interpolated climate surfaces for global land areas

Abstract: We developed interpolated climate surfaces for global land areas (excluding Antarctica) at a spatial resolution of 30 arc s (often referred to as 1-km spatial resolution). The climate elements considered were monthly precipitation and mean, minimum, and maximum temperature. Input data were gathered from a variety of sources and, where possible, were restricted to records from the 1950 – 2000 period. We used the thin-plate smoothing spline algorithm implemented in the ANUSPLIN package for interpolation, using latitude, ...

2004

Evaluating alternative data sets for ecological niche models of birds in the Andes

Abstract: Ecological niche modeling (ENM) is an effective tool for providing innovative insights to questions in evolution, ecology and conservation. As environmental datasets accumulate, modelers need to evaluate the relative merit of different types of data for ENM. We used three alternative environmental data sets: climatic data, remote- sensing data...

2001

Temporal variation in the diet of black curassows (Crax alector)

Abstract: We document the daily consumption of different food types by three Black Curassows (Crax alector) and its variation within and among seasons (rainy, transition, and dry) in Tinigua National Park, Northwestern Colombian Amazon. We also present a list of diffferent species consumed by curassows and the proximate nutritional composition of some foods frequently eaten by these birds. About half of the items eaten by curassows were fruits (111 species), but the birds also ate considerable amounts of seeds (42 species), leaves (six species), invertebrates (at least 21 Orders), and seedlings (11 species); and smaller amounts of soil, flowers (nine species), roots, galls, small vertebrates (frogs, lizards, and mice) and parts of carcasses of larger vertebrates (monkeys and armadillos). Daily consumption of ...

Use of space by a pair of Salvin’s curassows (Mitu salvini) in Northwestern Colombian Amazon

Abstract: We studied home-range size, habitat-use, habitat preferences, and their relationships with fruit availability by a family of Salvin’s Curassows (Mitu salvini) between January and July 1999 at Tinigua National Park in the northwestern Colombian Amazon. We followed the group closely throughout the day, registering its activities, the time spent in each habitat, and the trajectory traveled. Habitat-use was evalu- ated in terms of area used and time spent in each habitat. Fruit availability was estimated in each habitat by fruit traps...

2000

Nesting records of five Antbird species from the Colombian Amazon

Abstract: Few nests of Amazonian antbirds (Thamnophilidae and Formicariidae) have been described. Here we present nesting records for five species of antbirds found in Tinigua National Park, Colombia. A pouch- shaped pensile nest of the Warbling Antbird (Hypocnemis cantator) in a treefall gap within seasonally flooded forest contained two eggs colored like those found in French Guiana but different from those in Amazonian Brazil and Peru. The Black-spotted Bare-eye (Phlegopsis nigromaculata) also nested in seasonally flooded forest; it constructed a cup-shaped nest inside a hollow rotten stump and laid two eggs. Two naked nestlings with bright yellow bills disappeared soon after hatching. Two cup-shaped nests of the Scale-backed Antbird (Hylophylax poecilinota) ...

The birds of CIEM, Tinigua National Park, Colombia: an overview of thirteen years of ornithological research

Abstract: Presentamos un panorama general de la investigación ornitológica desarrollada durante trece años en el Centro de Investigaciones Ecológicas Macarena (CIEM), una estación biológica de la Universidad de los Andes (Bogotá, Colombia) y Miyagi University of Education (Japón). El CIEM está ubicado en un bosque húmedo tropical de tierras bajas al norte de la Amazonia colombiana (02°40'N 74°10'W), un lugar de gran importancia biogeográfica por la confluencia de elementos andinos, amazónicos, de los llanos y del escudo guyanés. H asta la fecha, hemos registrado un total de 441 especies de aves incluyendo 18 migratorias Neárticas y cinco migratorias australes...