About

Our Behavioral Ecophysics lab focuses on the study of organismal mechanisms (e.g., physiology, biomechanics) in light of biotic and abiotic interactions, with the goal of establishing explicit links between physical laws and rules of life, from individual to ecological scales. A central challenge of biological studies is to describe functional links between underlying architecture (e.g., genotype, phenotype) and emergent phenomena (e.g., performance, ecological patterns). To meet this challenge, it is necessary to identify and quantify causal relationships between variation in traits, such as wing and bill shape, and corresponding capabilities, such as cost of flight and feeding, of their possessors. Having this information allows us to unveil the connections between these capabilities and realized patterns (e.g., resource use, competition strategies), and thus their ecological and evolutionary implications. We focus on nectar-feeding animals to establish links between morphology, perf

Selected publications

• Data from: Foraging plasticity and physiological adaptations enable hummingbirds to subsist on dilute nectars

  Open MIND · 2026-01-20

  datasetOpen access

  Hummingbirds frequently feed on small volumes (< 30 µl) of sucrose-rich nectars. Climate change is expected to affect both the abundance and the concentrations of accumulated nectar. Using experimental feeding trials and field-collected measures of daily energy expenditure and floral nectar contents, we test the nectar dilutions at which hummingbirds can no longer meet their daily energy needs. We found across 14 hummingbird species that they are limited in how much they can increase their feeding rate (compensatory feeding) with decreasing nectar concentrations: nectar consumption increased until dilutions of 4-6 % sucrose, where birds fed at a maximum feeding rate (0.70 gNECTAR gBODYMASS -1 hr-1), after which nectar consumption (and corresponding sucrose intake) decreased. Integrating lab-tested maximum feeding rate with daily energy expenditure estimated from free-living hummingbirds, we found most species could meet daily energy needs while feeding on dilute nectars, but there is an average dilution threshold (~7 % sucrose). Hummingbirds may cope with energy deficits caused by variability in resources and competition with other nectarivores by adjusting their time spent foraging. Our energy budget models show that to meet average daily energetic needs, hummingbirds could feed ~2 hours on concentrated nectars, or an unattainable 19 hours feeding on dilute nectars. We show that maximum feeding rates pose a physiological cap on hummingbirds’ ability to use dilute nectars, which has implications for hummingbird survival and ultimately pollination. Thus, nectars provided by trochilophilous plants should be more concentrated than this dilution threshold. This mechanistic understanding may inform future work on the impacts of changes in flower phenology and nectar quality on hummingbirds.

  PublisherDOI

• Pauses in a fast-paced life: Intermittent hovering in hummingbirds

  bioRxiv (Cold Spring Harbor Laboratory) · 2026-04-18

  articleSenior author

  Abstract Hummingbirds are known for sustained hovering powered by rapid and continuous wingbeats. Here, we describe and quantify a novel flight behavior—intermittent hovering—in which hovering hummingbirds momentarily pause their wing motion mid-air but maintain their vertical position in space, keeping their wings fully extended at the end of the upstroke. We present the first systematic account of flap-pauses and wing coloration across hummingbirds, and evaluate potential morphological and ecological correlates, as well as evolutionary patterns in the expression of this behavior. Slow-motion footage from 86 species spanning all nine major hummingbird clades shows that at least 45 species exhibited flap-pauses during sustained hovering. Phylogenetic comparative analyses revealed that hovering pauses are evolutionarily conserved and significantly associated with both greater body mass and longer wings. Furthermore, we found that the 16 species in our study with colored underwings also exhibit significantly longer wings. The convergence of intermittent hovering, wing elongation, and chromatic traits leads us to hypothesize that this flight behavior plays a role in visual and/or auditory communication.

  PublisherDOI

• Variable evidence of radio-tag backpacks affecting hummingbird time budgets in captivity

  Animal Biotelemetry · 2026-02-26

  articleOpen accessSenior author

  With wildlife-tracking devices miniaturizing rapidly to enable ever-more research on ever-smaller taxa, there is a newfound urgency for affordable, field-accessible biologging ethics studies. We designed a 3-hour time-budget experiment to investigate how radio-transmitter backpacks affect hummingbirds’ behavior in Colombia. Using a large flight arena, we individually filmed 25 Black-throated Mangoes (Anthracothorax nigricollis) under two randomized treatments, tagged and untagged, to characterize and quantitatively compare behavior. We created time-budget breakdowns of our behaviors of interest—flying, hover-feeding, preening, and perching—then fit a series of linear mixed-effects models to determine the effects of tagging and additional experimental and environmental variables on behavior. We also designed an aviary-style “Entanglement Experiment” (n = 30) to determine if any individuals would snag on vegetation while equipped with the backpack harness, and tested 6 additional birds in this enclosure overnight for any longer-term negative effects. When tagged, individuals on average spent overall less time flying (with fewer and shorter bouts); and more total time feeding, preening (with more and longer bouts in both cases), and perching (with fewer but longer bouts)—however, this difference in total duration was only statistically significant in the case of preening. Our best-supported models also highlighted the importance of the following additional effects: whether or not the bird was undergoing its first or second 1.5-hour treatment (birds flew significantly more in their second treatment), bird mass (lighter birds fed significantly longer overall), and the time of day (birds preened significantly more in the afternoon than the morning, and more in the evening than the afternoon). No individuals in this captive study became entangled in vegetation or exhibited any adverse overnight effects from harness wear. In our captive study, radio-transmitter backpacks significantly affected the amount of time that hummingbirds spent preening, and additional environmental variables helped explain behavioral differences in each bird’s treatments. While being in a confined space doubtlessly affected the behavior of individuals, our experimental model is relatively straightforward to fine-tune to other small avian taxa and is suitable for remote conditions, providing a useful basis for examining species-specific effects of biologging prior to starting field studies.

  PublisherDOI

• Convergent and lineage-specific genomic changes shape adaptations in sugar-consuming birds

  Science · 2026-02-26 · 2 citations

  article

  High-sugar diets cause human metabolic diseases, yet several bird lineages convergently adapted to feeding on sugar-rich nectar or fruits. We investigated the underlying molecular mechanisms in hummingbirds, parrots, honeyeaters, and sunbirds by generating nine new genomes and 90 tissue-specific transcriptomes. Comparative screens revealed an excess of repeated selection in both protein-coding and regulatory sequences in sugar-feeding birds, suggesting reuse of genetic elements. Sequence or expression changes in sugar-feeders affect genes involved in blood pressure regulation and lipid, amino acid, and carbohydrate metabolism, with experiments showing functional changes in honeyeater hexokinase 3. MLXIPL , a key regulator of sugar and lipid homeostasis, showed convergent sequence and regulatory changes across all sugar-feeding clades; experiments revealed enhanced sugar-induced transcriptional activity of hummingbird MLXIPL , highlighting its adaptive role in high-sugar diets.

  PublisherDOI

• Draft assemblies for 177 bird species enhance genus-level coverage

  GigaScience · 2026-05-08

  articleOpen access

  BACKGROUND: With over 10,000 recognized species, birds constitute one of the most diverse and widely distributed vertebrate groups. Although avian genomics has advanced rapidly over the past decade, substantial gaps remain across the global avifauna. Filling these gaps is essential for understanding macroevolutionary patterns, population structure, and the molecular basis of ecological and behavioral diversity. Worldwide museum collections represent invaluable resources for filling these gaps, yet the typically degraded DNA and limited quantities from historical specimens have posed significant challenges for generating high-quality genome assemblies. RESULTS: Here, the Bird Genome 10 K (B10K) Project adopted low-input sequencing strategies that reduce costs while improving assembly quality compared with earlier order- and family-level genomes. Using mainly stLFR, complemented by 10X Genomics and standard next-generation sequencing, we assembled 177 avian genomes from museum specimens and tissue collections representing 161 genera, including 102 newly sequenced at the genomic level. The assemblies average ∼1.2 Gb in size, with scaffold N50 = 8.03 Mb, contig N50 = 120 kb, 93% BUSCO completeness, and Merqury QV score of 56. CONCLUSIONS: These genomes greatly expand avian taxonomic coverage and demonstrate the efficiency of low-input sequencing for generating high-quality assemblies from limited and often degraded material sourced from museum specimens. This resource provides a foundation for comparative genomics, conservation genetics, and evolutionary studies across the avian tree of life.

  PublisherDOI

• suwo: Access Nature Media Repositories

  2026-04-20

  datasetOpen accessSenior author

  Streamline searching, downloading and formatting of nature media files (e.g. audios, photos) from online repositories. The package offers functions for obtaining media metadata from online repositories, downloading associated media files and updating data sets with new records.

  PublisherOA PDFDOI

• Plant-pollinator trait matching affects pollen transfer but not feeding efficiency of Australian honeyeaters (Aves, Meliphagidae)

  Communications Biology · 2025-03-01 · 1 citations

  articleOpen accessSenior author

  Animal pollination is common among flowering plants. Increased morphological matching between floral and pollinator traits is thought to increase pollen transfer and feeding efficiency, but we lack studies that empirically demonstrate this. Working with Australian honeyeaters, we find that there is positive correlation between bill-corolla matching and pollen deposition at flowers, but no correlation with how efficiently birds can extract floral nectar. The species with the lowest bill-corolla matching deposited the fewest pollen grains but had the highest feeding efficiency, showing that bill-corolla matching expectations were met on the plant side of this interaction but not on the pollinator side. Finally, we find different interspecific patterns of pollen deposition at the scales of a single flower visit versus the landscape, due to differences in patterns of plant visitation. This work illustrates the need for more studies that directly correlate trait matching to fitness proxies of plants and avian pollinators.

  PublisherOA PDFDOI

• Sharper, straighter, stiffer, stronger: sexually dimorphic bill shape enhances male stabbing performance in the green hermit hummingbird ( <i>Phaethornis guy</i> )

  Journal of Experimental Biology · 2025-10-29 · 4 citations

  articleOpen accessSenior author

  Bill sexual dimorphism has been primarily linked to differential use of food resources between sexes. However, intrasexual selection has been suggested to also influence hummingbird bill morphology. Males of Phaethornis longirostris (long-billed hermit) possess sharp, elongated, dagger-like bill-tips that enhance puncturing ability and territory defense during male-male lekking combat. Yet, the prevalence of weaponized bills in hermits and the impact of bill shape on fighting performance remain unexplored. We employed 3D modelling and finite element analysis to explore bill dimorphism and stabbing performance in another lekking hummingbird: Phaethornis guy (green hermit). Our results reveal that P. guy exhibits a male-specific bill-tip dagger, and that males' straighter bills show greater biomechanical performance during stabbing tests, transmitting forces more efficiently (strain energy) and reducing the risk of breakage (von Mises stress). These findings provide further evidence of bill-tip weaponry and support a role of agonistic interactions in the evolution of bill dimorphism.

  PublisherOA PDFDOI

• Quantifying degradation in animal acoustic signals with the R package baRulho

  Methods in Ecology and Evolution · 2025-01-24 · 6 citations

  articleOpen accessSenior author

  Abstract Animal acoustic signals are shaped by selection to convey information based on their tempo, intensity, and frequency. However, sound signals degrade as they transmit over space and across physical obstacles (e.g., vegetation or infrastructure), which affects communication potential. Therefore, propagation experiments are designed to quantify changes in signal structure in a given habitat by broadcasting and re‐recording animal sounds at increasing distances. We introduce ‘baRulho’, an R package designed to simplify the implementation of sound propagation experiments. We highlight the package features with a case study testing the effects of habitat and acoustic structure on signal propagation, two common factors evaluated in such experiments. Synthesized sounds that varied in frequency, duration, and frequency and amplitude modulation were broadcast and re‐recorded at five increasing distances in open and closed understory at the Bosque de Tlalpan, Mexico City. With this data, we showcase baRulho's functions to prepare master sound files, annotate re‐recorded test sounds, as well as to calculate and visualize measures that quantify the degradation of acoustic signals in the time and frequency domain. Degradation measures in baRulho adequately quantified acoustic degradation, following predicted patterns of sound propagation in natural environments. Re‐recorded signals degraded less in open understory compared to closed understory, with higher‐frequency sounds exhibiting more degradation. Furthermore, frequency modulated sounds degraded to a greater extent than pure tones. The increased attenuation and reverberation observed in higher frequency sounds and closed habitats suggest that factors such as absorption and scattering by vegetation play significant roles in propagation patterns. The R package ‘baRulho’ provides an open‐source, user‐friendly suite of tools designed to facilitate the analysis of animal sound degradation. Notably, baRulho offers similar results to other sound analysis software but with significantly reduced processing time. Moreover, the package minimizes the potential for user error through automated test file annotation and verification procedures. We hope that baRulho can help enhance accessibility to propagation experiments within the research community, ultimately contributing to a deeper understanding of the ecological drivers of animal communication systems.

  PublisherOA PDFDOI

• Temporal patterns of dominance in a hummingbird assemblage

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-12-09

  articleOpen accessSenior author

  Abstract A substantial gap in dominance hierarchies research is understanding how such relationships change over time. Previous studies have generally used a single interaction matrix, assuming that dominance is temporally consistent. Yet food sources can be scarce and temporary, leading to changes in species frequency and assemblage composition. Hummingbird assemblages fluctuate as these tiny birds track seasonal floral resources, with individual movements affecting species composition. Artificial feeders, which may foster a greater number of aggressive interactions, provide a stable environment for studying dominance, unlike ephemeral and shifting wild resources. To assess the temporal stability of dominance relationships, we documented aggressive interactions in a hummingbird assemblage over three months on the western slope of the eastern Cordillera of Colombian Andes. We tracked local changes in species composition and visit frequency, recording interactions among 11 hummingbird species using high-speed cameras at three time scales: hour, day, and month. Dominance relationships and their certainty were analyzed through Perc analyses and interaction networks. Over three months of recording, and perusing over 27 hours of non continuous highspeed videos, we registered 3,907 aggressive interactions and 12,629 visits. Our results revealed substantial temporal variation in dominance relationships, species composition, and visit frequency, even within the constant food source that feeders provide. Dominance hierarchies were generally intransitive, with large species dominating, but also with smaller species occasionally winning interactions. We found high uncertainty in dominance relationships within shorter intervals with fewer interactions ( e.g ., hourly); and that rank changes between dominant species across months and days were linked to shifts in feeder visits. We recommend that future studies incorporate temporal variation, certainty analyses, and interaction networks to determine whether dominance relationships are stable enough to form reliable hierarchies and to explore the ecological significance of reversals in dominance and associated determinants. Highlights Dominance fluctuates across temporal scales, with monthly, daily, and hourly variations. Hierarchies become less stable at finer temporal scales. Body size and feeder visitation frequency shape dominance interactions. Smaller species initiate more aggressive interactions but lose more frequently. Relationships among dominant species are less predictable than among subordinates.

  PublisherDOI

Labs

• Rico-Guevara LabPI

Awards & honors

• Pitelka Award for Excellence in Research, International Soci…
• Carl Gans Young Investigator Award, Society for Integrative…
• NSF CAREER Award (2024)
• Distinguished Alumnus Award in Science, Universidad Nacional…