Hummingbird-pollinated Plants Research Articles

Intraspecific variation in pollination ecology due to altitudinal environmental heterogeneity.

Plant-pollinator interactions are constrained by floral traits and available pollinators, both of which can vary across environmental gradients, with consequences for the stability of the interaction. Here, we quantified how the pollination ecology of a high-mountain hummingbird-pollinated plant changes across a progressively more stressful environmental gradient of the Venezuelan Andes. We compared pollination ecology between two populations of this plant: Piedras Blancas (PB) and Gavidia (GV), 4450 and 3600 m asl, respectively. We hypothesised that self-compatibility might be higher at the higher altitude site, however we found that flowers showed similar capacities for self-compatibility in both localities. Seed production by flowers exposed to natural pollinators was significantly higher in the lower locality, where we also found higher nectar quality, larger flowers and increased frequencies of pollinator visitations. Interestingly, the population energy offered in the nectar was the same for both localities due to the higher density and floral aggregation found in the higher altitude population. Our study demonstrates how two plant populations in different environmental conditions have different pollination ecology strategies. Pollinator visitations or their absence result in trait associations in one population that are independent in the other. These population differences are not explained by differences in pollinator assembly, but by environmental heterogeneity.

Effect of plant traits and network metrics on pollen limitation in hummingbird-pollinated plants from the Brazilian Campos Rupestres

Pollen limitation (PL) can be an important estimate of the contribution of pollinators to the reproductive success of plants. PL often varies between species within the same community, and interspecific variation in PL may be related to plant traits and interaction patterns. However, few studies have investigated its drivers at the community level. In this study we assessed PL and its relationship with the dependence of plants on pollinators, floral morphology, nectar production and descriptors of the role of plant species in the interaction network in which they are embedded (linkage level, interaction strength, specialization and c or z coefficients) for 28 plant species pollinated by hummingbirds in the Brazilian Campos Rupestres. In the studied plant community, the prevalence of PL was high, but intensity was low, with 8 species (29 %) presenting some degree of PL. Nectar volume and nectar concentration were negatively related to PL, while plant species with higher dependence on pollinators for reproduction presented higher PL. We did not detect a relationship between network metrics and pollen limitation, this could reflect the low variation in species roles in the community, with most plant species being peripherals (linked to few and generalized pollinators). We demonstrated that plant traits were more important than network metrics in predicting interspecific variation in pollen limitation in the studied plant-hummingbird network. We suggest that evaluating pollen limitation within plant communities is key to uncover the drivers of pollination deficits.

The effect of species role and trait-matching on plant fitness in a plant-hummingbird interaction network

In animal-pollinated plants, fitness is affected by pollinator attraction and plant-pollinator trait matching. Plant-pollinator interactions are often characterized using metrics derived from mutualistic networks, such as centrality and interaction selectivity. This approach often focuses on the species level, thus neglecting significant among-individual variation in attracting foraging pollinators and associated fitness consequences for plants. Here, we tested if centrality and interaction selectivity were related to fitness at the species and the individual level for 14 hummingbird-pollinated plant species in the Atlantic Forest. In addition, we tested if plant-pollinator trait-matching influenced plant fitness. At the species-level, we did not find a relationship between plant fitness and centrality nor interaction selectivity; we found instead that plant fitness increased with higher trait-matching between bill and corolla lengths. At the individual-level we found that individuals with higher centrality values produced less seeds, likely due to lower quality in pollen deposition. Moreover, individuals with a lower interaction selectivity also produced more seeds, probably because of higher conspecific pollen flow. Our results show that individual position and interaction selectivity within pollination networks may have important implications for pollination effectiveness and hence plant fitness.

Plant-hummingbird pollination networks exhibit limited rewiring after experimental removal of a locally abundant plant species.

Mutualistic relationships, such as those between plants and pollinators, may be vulnerable to the local extinctions predicted under global environmental change. However, network theory predicts that plant-pollinator networks can withstand species loss if pollinators switch to alternative floral resources (rewiring). Whether rewiring occurs following species loss in natural communities is poorly known because replicated species exclusions are difficult to implement at appropriate spatial scales. We experimentally removed a hummingbird-pollinated plant, Heliconia tortuosa, from within tropical forest fragments to investigate how hummingbirds respond to temporary loss of an abundant resource. Under the rewiring hypothesis, we expected that behavioural flexibility would allow hummingbirds to use alternative resources, leading to decreased ecological specialization and reorganization of the network structure (i.e. pairwise interactions). Alternatively, morphological or behavioural constraints-such as trait-matching or interspecific competition-might limit the extent to which hummingbirds alter their foraging behaviour. We employed a replicated Before-After-Control-Impact experimental design and quantified plant-hummingbird interactions using two parallel sampling methods: pollen collected from individual hummingbirds ('pollen networks', created from >300 pollen samples) and observations of hummingbirds visiting focal plants ('camera networks', created from >19,000 observation hours). To assess the extent of rewiring, we quantified ecological specialization at the individual, species and network levels and examined interaction turnover (i.e. gain/loss of pairwise interactions). H. tortuosa removal caused some reorganization of pairwise interactions but did not prompt large changes in specialization, despite the large magnitude of our manipulation (on average, >100 inflorescences removed in exclusion areas of >1 ha). Although some individual hummingbirds sampled through time showed modest increases in niche breadth following Heliconia removal (relative to birds that did not experience resource loss), these changes were not reflected in species- and network-level specialization metrics. Our results suggest that, at least over short time-scales, animals may not necessarily shift to alternative resources after losing an abundant food resource-even in species thought to be highly opportunistic foragers, such as hummingbirds. Given that rewiring contributes to theoretical predictions of network stability, future studies should investigate why pollinators might not expand their diets after a local resource extinction.

Why are some hummingbird-pollinated plant clades so species-rich?

Hummingbird pollination evolved numerous times independently and has been reported from 404 plant genera distributed over 68 angiosperm families (Abrahamczyk and Kessler 2015). This article is protected by copyright. All rights reserved.

Bumblebee floral neighbors promote nectar robbing in a hummingbird-pollinated plant species in Patagonia

Bumblebee floral neighbors promote nectar robbing in a hummingbird-pollinated plant species in Patagonia

Influence of plant reproductive systems on the evolution of hummingbird pollination.

Many hummingbird‐pollinated plant species evolved from bee‐pollinated ancestors independently in many different habitats in North and South America. The mechanisms leading to these transitions are not completely understood. We conducted pollination and germination experiments and analyzed additional reproductive traits in three sister species pairs of which one species is bee‐ and the other hummingbird‐pollinated. All hummingbird‐pollinated species showed higher seed set and germination rates in cross‐pollinated than in self‐pollinated flowers. In the self‐compatible, bee‐pollinated sister species this difference did not exist. As expected, seed set and germination rate were higher after cross‐pollination in the largely self‐incompatible genus Penstemon independently of the pollination syndrome. However, the bird‐pollinated species produce only half of the amount of ovules and pollen grains per flower compared to the bee‐pollinated sister species. This indicates that hummingbird pollination is much more efficient in self‐incompatible populations because hummingbirds waste less pollen and provide higher outcrossing rates. Therefore, hummingbird pollination is less resource costly. Overall, we suggest that hummingbirds may increase the reproductive success compared to bees, influencing the evolution of hummingbird pollination in ecosystems with diverse bee assemblages.

The Level of Pollination Specialization Affects the Relationship between the Shape of Flowers and the Bills of Their Hummingbird Pollinators in Antillean Gesneriaceae

Premise of research. Pollinators are known to impose strong selection on floral shape. Particularly well studied is the relationship between the flowers of hummingbird-pollinated plant species and the bills of their pollinators. However, no studies to date have evaluated whether these relationships vary according to the level of pollination specialization. Here, we quantify the relationship between the corolla shape of Antillean Gesneriaceae and the bills of their hummingbird pollinators for species with a specialist (one functional group of pollinators: hummingbirds) and a generalist (more than one functional group of pollinators: hummingbirds, bats, and insects) pollination strategy.Methodology. We used phylogenetic generalized least squares analyses on linear measurements and phylogenetic two blocks partial least squares on multivariate geometric morphometrics data to test whether and how the variation in the corolla shape of the Antillean Gesneriaceae is correlated to the shape of the bills of their hummingbird pollinators.Pivotal results. We found that corolla shape is correlated with the bill shape of the hummingbird pollinators but that the nature of this relationship differed between pollination specialists and generalists. For example, corolla curvature was positively correlated with bill curvature for specialists but not for generalists.Conclusions. Our study suggests that pollinators affect the evolution of flower shape but that the nature and strength of the selective pressures are affected by the pollinator guild of the pollinators in the Antillean Gesneriaceae.

Macroecological patterns of resource use in resident and migratory hummingbirds

Hummingbirds (Family Trochilidae) are key pollinators in several biodiversity hotspots, including the California Floristic Province in North America. Relatively little is known about how hummingbird diets change throughout the year, especially with regard to how migratory hummingbirds affect resident hummingbirds at stopover sites. In this study, we examine how hummingbird species, migratory status, sex, geographic region and local plant diversity influence floral resource use before, during, and after an influx of migratory hummingbirds (primarily Rufous hummingbirds, Selasphorus rufus) across California. We expected distinct floral resource use based upon species’ migratory status (resident vs. migrant), sex, sampling period, and geographic region. We employed DNA metabarcoding to detect plant DNA in hummingbird fecal samples to analyze diet diversity, composition, overlap, and interaction networks. We found significant effects of sex, sampling period, and migratory status on the alpha and beta diversity of plant taxa present in fecal samples. Analyses of Anna's hummingbirds (Calypte anna) alone revealed that female fecal samples contained higher plant species richness. In addition to hummingbird-pollinated plants, fecal samples also contained non-ornithophilous plants and species of agricultural importance. Diet overlap and plant-pollinator network analyses revealed high overlap in plant taxa used between hummingbird species, and networks were more connected, less nested, and less specialized than null models. DNA metabarcoding is minimally invasive and provides a detailed view of hummingbird diet, permitting large-scale studies. Insights into hummingbird diets are especially valuable given the logistical difficulties of directly observing floral visitation and foraging across broad temporal and spatial scales.

Birds Perceive More Intraspecific Color Variation in Bird-Pollinated Than Bee-Pollinated Flowers.

Pollinator-mediated selection is expected to constrain floral color variation within plant populations. Here, we test for patterns of constraint on floral color variation in 38 bee- and/or hummingbird-pollinated plant species from Colorado, United States. We collected reflectance spectra for at least 15 individuals in each of 1–3 populations of each species (total 78 populations) and modeled perceived color variation in both bee and bird visual spaces. We hypothesized that bees would perceive less intraspecific color variation in bee-pollinated species (vs. bird-pollinated species), and reciprocally, birds would perceive less color variation in bird-pollinated species (vs. bee-pollinated species). In keeping with the higher dimensionality of the bird visual system, birds typically perceived much more color variation than bees, regardless of plant pollination system. Contrary to our hypothesis, bees perceived equal color variation within plant species from the two pollination systems, and birds perceived more color variation in species that they pollinate than in bee-pollinated species. We propose hypotheses to account for the results, including reduced long-wavelength sensitivity in bees (vs. birds), and the ideas that potential categorical color vision in birds and larger cognitive capacities of birds (vs. bees) reduces their potential discrimination against floral color variants in species that they pollinate, resulting in less stabilizing selection on color within bird-pollinated vs. bee-pollinated species.

Spatio-temporal effects of climate change on the geographical distribution and flowering phenology of hummingbird-pollinated plants.

Tropical plant species are already suffering the effects of climate change and projections warn of even greater changes in the following decades. Of particular concern are alterations in flowering phenology, given that it is considered a fitness trait, part of plant species ecological niche, with potential cascade effects in plant-pollinator interactions. The aim of the study was to assess the potential impacts of climate change on the geographical distribution and flowering phenology of hummingbird-pollinated plants. We implemented ecological niche modelling (ENM) to investigate the potential impacts of different climate change scenarios on the geographical distribution and flowering phenology of 62 hummingbird-pollinated plant species in the Brazilian Atlantic Forest. Distribution models indicate future changes in the climatic suitability of their current habitats, suggesting a tendency towards discontinuity, reduction and spatial displacement. Flowering models indicate that climate can influence species phenology in different ways: some species may experience increased flowering suitability whereas others may suffer decreased suitability. Our results suggest that hummingbird-pollinated species are prone to changes in their geographical distribution and flowering under different climate scenarios. Such variation may impact the community structure of ecological networks and reproductive success of tropical plants in the near future.

Floral isolation and pollination in two hummingbird-pollinated plants: the roles of exploitation barriers and pollinator competition

Differences in feeding performance and aggressive abilities between species and sexes of hummingbirds are often associated with the partitioning of their food sources, but whether such partitioning results in floral isolation (reproductive isolation at the stage of pollination) has received little attention. We examined components of floral isolation and pollinator effectiveness of Heliconia caribaea and H. bihai on the island of Dominica, West Indies. The short flowers of H. caribaea match the short bills of male Anthracothorax jugularis, its primary pollinator, whereas the long flowers of H. bihai match the long bills of female A. jugularis, its primary pollinator. In pollination experiments, both sexes of A. jugularis were equally effective at pollinating the short flowers of H. caribaea, which they preferred to H. bihai, whereas females were more effective at pollinating the long flowers of H. bihai. Moreover, an average difference in length of 12 mm between H. caribaea and H. bihai flowers did not prevent heterospecific pollen transfer, and both sexes transported pollen between the two plant species. In field studies using powdered dyes as pollen analogs, however, heterospecific pollen transfer was minimal, with only 2 of 168 flowers receiving dye from the other species. The length of H. bihai flowers acted as an exploitation barrier to male A. jugularis, which were unable to completely remove nectar from 88% of the flowers they visited. In contrast, interference competition combined with high floral fidelity through traplining prevented female A. jugularis from transferring pollen between the two Heliconia species. A combination of exploitation barriers, interference and exploitative competition, and pollinator preferences maintains floral isolation between these heliconias, and may have contributed to the evolution of this hummingbird-plant system.

Bracts and long-tube flowers of hummingbird-pollinated plants are conspicuous to hummingbirds but not to bees

The ‘bee avoidance’ hypothesis posits that the colour of hummingbird-pollinated flowers will exclude bees, especially in long-tubed flowers, which are more subject to bee nectar robbers. However, many hummingbird-pollinated plants possess bracts, and the role of bract colour in bee avoidance has not previously been tested. We assessed the signal value of bract colours by comparing them with the petals of species with and without bracts. We expected the bracts would contrast and enhance the petal signal more to hummingbirds than to bees, especially in long-tubed flowers. We compared bract signals in the hummingbird and bee visual systems, petal signals between the bract and leaf background, and the relationship between flower length and bract colour. For species with bracts, the bracts contrasted more than petals in the hummingbird visual system, but less in the bee visual system. Petals contrasted more with the bract background than with the leaf background to hummingbirds, but not to bees. Bract colours of long-tubed flowers contrasted less than those of short-tubed flowers to bees. Our results show that bracts are attractive to hummingbirds, and have the potential to exclude antagonists in hummingbird-pollinated plants. These patterns support the bee avoidance hypothesis, especially in long-tubed flowers.

Resource partitioning by color in a tropical hummingbird

Many nectar-feeding animals use cues (floral signals) to locate, identify, and discriminate between floral resources. Whether competing pollinators can use cues to partition resources, however, has received little attention despite examples of pollinators differing in resource use. We examined whether sexes of the purple-throated carib hummingbird, Anthracothorax jugularis, partition artificial nectar sources (feeders) by color (red or yellow) or position (left or right), and whether such partitioning changes in response to changes in nectar reward. At equal nectar concentrations, sexes partitioned resources by color, but when one of the colors was reduced in quality, dominant males visited the more rewarding color, although they did not completely displace subordinate females. The position of the feeder had no effect on resource partitioning, and in the absence of color cues, male and female hummingbirds did not partition feeders. Our results differ from earlier studies where hummingbirds responded more to position than to color. We suggest that this difference may result from defense of patches as opposed to choice of individual food items as well as from differences between temperate and tropical hummingbird-plant communities in floral colors. Hummingbird-pollinated plants in many temperate communities converge on red flowers, which may eliminate color as a cue for resource partitioning, whereas the availability of plant species differing in floral color and pattern may provide tropical nectarivores with cues for resource subdivision. Our results have major implications for the evolution of species diversity. Because plants and pollinators may reciprocally affect each other’s evolution, partitioning of floral resources by color may not only affect traits of pollinators but also may maintain and drive the diversification of floral colors and other floral traits.

The potential indirect effects among plants via shared hummingbird pollinators are structured by phenotypic similarity.

Plant species within communities may overlap in pollinators' use and influence visitation patterns of shared pollinators, potentially engaging in indirect interactions (e.g., facilitation or competition). While several studies have explored the mechanisms regulating insect-pollination networks, there is a lack of studies on bird-pollination systems, particularly in species-rich tropical areas. Here, we evaluated if phenotypic similarity, resource availability (floral abundance), evolutionary relatedness and flowering phenology affect the potential for indirect effects via shared pollinators in hummingbird-pollinated plant species within four communities in the Brazilian Atlantic forest. Among the evaluated factors, phenotypic similarity (corolla length and anther height) was the most important variable, while resource availability (floral abundance) had a secondary importance. On the other hand, evolutionary relatedness and flowering phenology were less important, which altogether highlights the relevance of convergent evolution and that the contribution of a plant to the diet of the pollinators of another plant is independent of the level of temporal overlap in flowering in this tropical system. Interestingly, our findings contrast with results from multiple insect-pollinated plant communities, mostly from temperate regions, in which floral abundance was the most important driver, followed by evolutionary relatedness and phenotypic similarity. We propose that these contrasting results are due to high level of specialization inherent to tropical hummingbird-pollination systems. Moreover, our results demonstrated that factors defining linkage rules of plant-hummingbird networks also determinate plant-plant potential indirect effects. Future studies are needed to test if these findings can be generalized to other highly specialized systems. Overall, our results have important implications for the understanding of ecological processes due resource sharing in mutualistic systems.

Bird Predation By Praying Mantises: A Global Perspective

ABSTRACT We review 147 incidents of the capture of small birds by mantids (order Mantodea, family Mantidae). This has been documented in 13 different countries, on all continents except Antarctica. We found records of predation on birds by 12 mantid species (in the genera Coptopteryx, Hierodula, Mantis, Miomantis, Polyspilota, Sphodromantis, Stagmatoptera, Stagmomantis, and Tenodera). Small birds in the orders Apodiformes and Passeriformes, representing 24 identified species from 14 families (Acanthizidae, Acrocephalidae, Certhiidae, Estrildidae, Maluridae, Meliphagidae, Muscicapidae, Nectariniidae, Parulidae, Phylloscopidae, Scotocercidae, Trochilidae, Tyrannidae, and Vireonidae), were found as prey. Most reports (>70% of observed incidents) are from the USA, where mantids have often been seen capturing hummingbirds attracted to food sources in gardens, i.e., hummingbird feeders or hummingbird-pollinated plants. The Ruby-throated Hummingbird (Archilochus colubris) was the species most frequently reported...

"Hummingbird" floral traits interact synergistically to discourage visitation by bumble bee foragers.

Pollination syndromes are suites of floral traits presumed to reflect adaptations to attract and utilize a "primary" type of animal pollinator. However, syndrome traits may also function to deter "secondary" flower visitors that reduce plant fitness through their foraging activities. Here we use the hummingbird-pollinated plant species Mimulus cardinalis as a model to investigate the potential deterrent effects of classic bird syndrome traits on bumble bee foragers. To establish that M.cardinalis flowers elicit an avoidance response in bees, we assessed the choice behavior of individual foragers on a mixed experimental array of M.cardinalis and its bee-pollinated sister species M.lewisii. As expected, bees showed a strong preference against M.cardinalis flowers (only 22% of total bee visits were to M.cardinalis), but surprisingly also showed a high degree of individual specialization (95.2% of total plant transitions were between conspecifics). To determine M.cardinalis floral traits that discourage bee visitation, we then assessed foraging responses of individuals to M.cardinalis-like and M.lewisii-like floral models differing in color, orientation, reward, and combinations thereof. Across experiments, M.cardinalis-like trait combinations consistently produced a higher degree of flower avoidance behavior and individual specialization than expected based on bee responses to each trait in isolation. We then conducted a series of flower discrimination experiments to assess the ability of bees to utilize traits and trait combinations associated with each species. Relative to M.lewisii-like alternatives, M.cardinalis-like traits alone had a minimal effect on bee foraging proficiency but together increased the time bees spent searching for rewarding flowers from 1.49 to 2.65s per visit. Collectively, our results show that M.cardinalis flowers impose foraging costs on bumble bees sufficient to discourage visitation and remarkably, generate such costs through synergistic color-orientation and color-reward trait interactions. Floral syndromes therefore represent complex adaptations to multiple pollinator groups, rather than simply the primary pollinator.

The phylogeny of Heliconia (Heliconiaceae) and the evolution of floral presentation

Heliconia (Heliconiaceae, order Zingiberales) is among the showiest plants of the Neotropical rainforest and represent a spectacular co-evolutionary radiation with hummingbirds. Despite the attractiveness and ecological importance of many Heliconia, the genus has been the subject of limited molecular phylogenetic studies. We sample seven markers from the plastid and nuclear genomes for 202 samples of Heliconia. This represents ca. 75% of accepted species and includes coverage of all taxonomic subgenera and sections. We date this phylogeny using fossils associated with other families in the Zingiberales; in particular we review and evaluate the Eocene fossil Ensete oregonense. We use this dated phylogenetic framework to evaluate the evolution of two components of flower orientation that are hypothesized to be important for modulating pollinator discrimination and pollen placement: resupination and erect versus pendant inflorescence habit. Our phylogenetic results suggest that the monophyletic Melanesian subgenus Heliconiopsis and a small clade of Ecuadorian species are together the sister group to the rest of Heliconia. Extant diversity of Heliconia originated in the Late Eocene (39Ma) with rapid diversification through the Early Miocene, making it the oldest known clade of hummingbird-pollinated plants. Most described subgenera and sections are not monophyletic, though closely related groups of species, often defined by shared geography, mirror earlier morphological cladistic analyses. Evaluation of changes in resupination and inflorescence habit suggests that these characters are more homoplasious than expected, and this largely explains the non-monophyly of previously circumscribed subgenera, which were based on these characters. We also find strong evidence for the correlated evolution of resupination and inflorescence habit. The correlated model suggests that the most recent common ancestor of all extant Heliconia had resupinate flowers and erect inflorescences. Finally, we note our nearly complete species sampling and dated phylogeny allow for an assessment of taxonomic history in terms of phylogenetic diversity. We find approximately half of the currently recognized species, corresponding to half of the phylogenetic diversity, have been described since 1975, highlighting the continued importance of basic taxonomic research and conservation initiatives to preserve both described and undiscovered species of Heliconia.

Geographic distribution and trait-mediated causes of nectar robbing by the European bumblebee Bombus terrestris on the Patagonian shrub Fuchsia magellanica

Invasive floral visitors may obtain nectar rewards from native plants exerting nectar robbing. Nevertheless, the probability of a plant to be robbed will ultimately depend upon the accessibility constraints imposed by the phenotypes of flowers and animals, and putatively upon the abundance of animals. The alien bumblebee B. terrestris is widely distributed in the temperate forests of Chile, where it is exerting nectar robbing on flowers of F. magellanica. Its geographic distribution and the causes of nectar robbing, however, are currently unknown. The aim of this study is to evaluate the distribution of nectar robbing in a wide range of distribution of plants and animals, and the causes of nectar robbing in terms of floral and animal phenotypes, and in terms of animal abundances. The primary nectar robbing did not correlate with the latitude, longitude or altitude of populations, thus indicating an absence of cline variation in the causes of nectar robbing. The variability of primary nectar robbing seemingly showed a bimodal distribution, since the most represented categories were the low and high incidence of primary nectar robbing. Petal length, rather than other flora traits, coupled to the glossa length of animals, played a pivotal role in the probability of flowers to experience nectar robbing. The putative negative consequences upon the population persistence and the evolution and maintenance of floral phenotypes of hummingbird-pollinated plants strongly encourage new assessments.

Spatial effects of artificial feeders on hummingbird abundance, floral visitation and pollen deposition

Providing hummingbirds with artificial feeders containing sugar solution is common practice throughout the Americas. Although feeders can affect hummingbird foraging behavior and abundance, it is poorly understood how far this effect may extend. Moreover, it remains debated whether nectar-feeders have a negative impact on hummingbird-pollinated plants by reducing flower visitation rates and pollen transfer close to the feeders. Here, we investigated the effects of distance to nectar-feeders on a local hummingbird assemblage and the pollination of Psychotria nuda (Rubiaceae), a hummingbird-pollinated plant endemic to the Brazilian Atlantic Rainforest. At increasing distance (0–1000 m) from a feeding-station, where hummingbirds have been fed continuously for the past 13 years, we quantified hummingbird abundance, and rates of flower visitation and pollen deposition on P. nuda. We found that hummingbird abundance was unrelated to distance from the feeders beyond ca. 75 m, but increased steeply closer to the feeders; the only exception was the small hummingbird Phaethornis ruber, which remained absent from the feeders. Plants of P. nuda within ca.125 m from the feeders received increasingly more visits, coinciding with the higher hummingbird abundance, whereas visitation rate beyond 125 m showed no distance-related trend. Despite this, pollen deposition was not associated with distance from the feeders. Our findings illustrate that artificial nectar-feeders may locally increase hummingbird abundance, and possibly affect species composition and pollination redundancy, without necessarily having a disruptive effect on pollination services and plants’ reproductive fitness. This may apply not only to hummingbirds, but also to other animal pollinators.