Patagona Research Articles

Extreme elevational migration spurred cryptic speciation in giant hummingbirds

The ecoevolutionary drivers of species niche expansion or contraction are critical for biodiversity but challenging to infer. Niche expansion may be promoted by local adaptation or constrained by physiological performance trade-offs. For birds, evolutionary shifts in migratory behavior permit the broadening of the climatic niche by expansion into varied, seasonal environments. Broader niches can be short-lived if diversifying selection and geography promote speciation and niche subdivision across climatic gradients. To illuminate niche breadth dynamics, we can ask how "outlier" species defy constraints. Of the 363 hummingbird species, the giant hummingbird (Patagona gigas) has the broadest climatic niche by a large margin. To test the roles of migratory behavior, performance trade-offs, and genetic structure in maintaining its exceptional niche breadth, we studied its movements, respiratory traits, and population genomics. Satellite and light-level geolocator tracks revealed an >8,300-km loop migration over the Central Andean Plateau. This migration included a 3-wk, ~4,100-m ascent punctuated by upward bursts and pauses, resembling the acclimatization routines of human mountain climbers, and accompanied by surging blood-hemoglobin concentrations. Extreme migration was accompanied by deep genomic divergence from high-elevation resident populations, with decisive postzygotic barriers to gene flow. The two forms occur side-by-side but differ almost imperceptibly in size, plumage, and respiratory traits. The high-elevation resident taxon is the world's largest hummingbird, a previously undiscovered species that we describe and name here. The giant hummingbirds demonstrate evolutionary limits on niche breadth: when the ancestral niche expanded due to evolution (or loss) of an extreme migratory behavior, speciation followed.

Nectar robbing effects on pollinators of a key nectar source plant (Tecoma fulva, Bignoniaceae) in a dry tropical Andean valley

AbstractZoophilous flowering plants have features to attract their pollinators, which may also be used by exploiters like nectar robbers. Nectar robbers access nectar by probing flower corollas (primary robbing) or use existing holes (secondary robbing). Nectar robbing can negatively impact a plant's fitness directly by damaging the reproductive structures of the flower or indirectly by modifying the visitation patterns of pollinators. We tested the hypothesis that the robbed flowers are less visited by legitimate pollinators by comparing floral visitors and visitation frequency in primary‐, secondary‐, and un‐robbed flowers of Tecoma fulva spp. Altoandina, a native shrub species that is an important nectar source for nectarivores in the dry valleys of the Bolivian Andes (Bignoniaceae). The Giant Hummingbird, Patagona gigas (Trochilidae), was the main visitor of T. fulva and visited more frequently un‐robbed flowers, followed by secondary robbed and primary robbed flowers. The variation in visitation frequency may result in less pollen transport to robbed flowers, which may have negative consequences for the biological fitness, probably manifested in decreased seed production.Abstract in Spanish is available with online material.

A lightweight backpack harness for tracking hummingbirds

Hummingbirds and other lightweight bird species are challenging to track because they have limited capacity to carry devices for data‐logging. We present a simple and customizable three‐loop ‘backpack' harness for studying hummingbird migration and movement, with step‐by‐step instructions for harness construction and attachment. The harness has negligible weight and cost (< $0.50 USD/each), is easy for a single person to make and apply in the field, and it requires no complicated setup or equipment. We have field‐tested this harness on 74 giant hummingbirds Patagona gigas with three different types of tracking devices (geolocators, GPS tags and satellite transmitters) in Chile and Peru from 2017 to 2020. Based on recaptures to date, we report that harnesses last for at least two years, even under high UV‐light conditions. We found no evidence of adverse effects of the harnesses on birds after one to two years and apparent survival of geolocator‐tracked giant hummingbirds was in line with published estimates for other hummingbird species. This harness method is a practical and effective option for mounting ultra‐light devices on hummingbirds, and it can be readily modified for other species with short legs, prominent sternal keels and long wings.

Shrub canopy matrix decreases reproductive output of a sheltered plant via pollinator exclusion

Shrubs establish microenvironments under their canopies that can favor the growth of other plants. However, the shrub canopy could impede pollination by reducing the number of pollinator visits to sheltered plants, resulting in pollen limitation and decreased reproductive output. We assessed whether the presence of a nurse shrub species (Flourensia thurifera) alters the reproductive output of a sheltered cactus (Eriosyce coimasensis) via the restriction of access by the giant hummingbird (Patagona gigas) to E. coimasensis flowers. During two consecutive years (2018 – 2019), we excluded hummingbirds from individual cacti (using cages) and studied fruit set and seed production in two microhabitats: underneath shrubs and in open sites. In addition, we compared the reproductive mode of E. coimasensis in the two microhabitats. We observed that shrubs limit the reproduction of E. coimasensis, which strongly depends on P. gigas for seed production. Plants in open sites produced 80% more fruit and 76% more seeds than those growing underneath shrubs. The reproduction of caged individuals was low and similar to those growing beneath shrubs. In addition, plants underneath shrubs, but not in open sites, may suffer pollen limitation. Our results offer novel insights into plant-plant interactions and suggest potential trade-offs for sheltered cacti between the mild microclimatic conditions under the canopy, that could lead to larger plants and pollinator preclusion, which decreases the reproductive performance of sheltered plants.

Bees may drive the reproduction of four sympatric cacti in a vanishing coastal mediterranean-type ecosystem.

BackgroundSympatric congeneric plants might share pollinators, or each species might avoid competition by evolving specialized traits that generate partitions in pollinator assemblages. In both cases, pollen limitation (a decrease in the quality and quantity of compatible reproductive pollen) can occur, driving the plant mating system to autogamy as a mechanism of reproductive assurance. We assessed the relationships between pollinator assemblages and mating systems in a group of sympatric congeneric plants. We attempted to answer the following questions: (i) How similar are pollinator assemblages among sympatric cactus species? (ii) Which mating systems do sympatric cactus species use?MethodsWe studied sympatric Eriosyce taxa that inhabit a threatened coastal strip in a mediterranean-type ecosystem in central Chile. We performed field observations on four taxa and characterized pollinators during the years 2016 and 2017. We estimated differences in the pollinator assemblages using the Bray–Curtis index. To elucidate the mating systems, we conducted hand-pollination experiments using three treatments: manual cross-pollination, automatic self-pollination, and control (unmanipulated individuals). We tested differences in seed production for statistical significance using Kruskal–Wallis analysis.ResultsEriosyce subgibbosa showed a distinctive pollinator assemblage among the sympatric species that we studied (similarity ranged from 0% to 8%); it was visited by small bees and was the only species that was visited by the giant hummingbird Patagona gigas. Pollinator assemblages were similar between E. chilensis (year 2016 = 4 species; 2017 = 8) and E. chilensis var. albidiflora (2016 = 7; 2017 = 4); however, those of E. curvispina var. mutabilis (2016 = 7; 2017 = 6) were less similar to those of the aforementioned species. E. curvispina var. mutabilis showed the highest interannual variation in its pollinator assemblage (18% similarity). Reproduction in E. subgibbosa largely depends on pollinators, although it showed some degree of autogamy. Autonomous pollination was unfeasible in E. chilensis, which depended on flower visitors for its reproductive success. Both E. chilensis var. albidiflora and E. curvispina var. mutabilis showed some degree of autogamy.DiscussionWe observed differences in pollinator assemblages between E. subgibbosa and the remaining Eriosyce taxa, which depend on hymenopterans for pollen transfer. Pollinator assemblages showed considerable interannual variation, especially those of E. subgibbosa (ornithophilous syndrome) and E. curvispina var. mutabilis (melitophilous syndrome). Autogamous reproduction in these taxa may act as a reproductive assurance mechanism when pollinator availability is unpredictable. Our study contributes to improving our understanding of the reproductive systems of ecological interactions between threatened species in a Chilean mediterranean-type ecosystem.

Reproductive biology of Oreocereus fossulatus (Cactaceae), a long‐lived columnar cactus endemic to the tropical Andes

AbstractThe geographic dichotomy hypothesis suggests that columnar cacti inhabiting the tropics depend on flower visitors (birds and bats) for their pollination, showing highly specialized animal‐pollinated systems. This pattern has been demonstrated for the northern hemisphere; however, our knowledge of the species of columnar cacti growing in the southern tropics is still scarce. In this study, we studied the reproductive biology of Oreocereus fossulatus (Cactaceae, Tribe Trichocereae), an endemic, columnar cactus of the tropical Andes, to determine if its pollination system tends to be more generalized (mixed systems of autogamy and xenogamy) than specialized (xenogamy) as a consequence of the geographic position of where it lives. Observations of the frequency of visits showed that Patagona gigas (Trochillidae) is its main pollinator. It visits the flowers when they are open, coinciding with the periods of greater floral reward (dusk and dawn of the first day of anthesis). The treatments of autogamy, xenogamy and geitonogamy produced fruits, showing that O. fossulatus exhibits a generalized pollination system, in the same way as its congeneric species O. celsianus, which is distributed farther south in the Prepuna biogeographical region. Our results suggest that species partially specializing in pollination by hummingbirds and, besides, capable of autopollination, could be common in the tropical and subtropical Andes, probably as a response to the unpredictable environments present in their ecosystems.

Slush Mountain by B. R. Lie

Lie, Bjørn R. Slush Mountain. Vancouver: Simply Read Books, 2016. Print. It’s a clear, crisp morning on Slush Mountain. There’s not a cloud in the sky and the fresh snow shines in the sunlight.This basic yet delightfully illustrated book tells the simple pleasures of a day in the village and the slopes of Slush Mountain, located somewhere in the Norwegian mountains. Previously published in Norwegian under the title Slapsefjell, author-illustrator and graphic artist Bjørn Rune Lie gives us a day in the life of a busy resort town from the perspective of locals and visitors alike.Beginning in the morning, we start out on the Nordic tracks with cross-country skiers. But there are also white knuckle slopes and moguls for those interested in a little more speed. Throughout the day we visit Frostbite Fish Pond, watch loggers in the Sluggerdale Forest, travel up along the Gutsy Pines Gondola and the Chilly Winds Chairlift and take part in the exhilarating Slush Mountain Rally, replete with vintage snowmobiles. There are loads of eccentric characters with names like Bruce “the Spruce” Crampon, “Snow Blind” Jefferson and Michael Mittens, who much to my kids’ delight, spots a rare three-headed giant hummingbird while seated in the outdoor privy. The day is finished off in a cozy cabin while a family plays a board game while drinking hot chocolate.While there is no real plot, the nostalgic, retro-inspired illustrations are fun to look at and have lots of detail to engage even the youngest readers. Humans and animals alike are enjoying themselves on the slopes, the rally, and the hotel dance. My children noted that the skiers were not wearing helmets but understood that the bygone era in the artwork represented a different time in terms of alpine safety. This is a fun, sweet book that would be a nice gift for snow-loving kids and perfect for an elementary school library.Recommended: 3 stars out of 4 Reviewer: Debbie FeisstDebbie is a Public Services Librarian at the H.T. Coutts Education Library at the University of Alberta. When not renovating, she enjoys travel, fitness and young adult fiction.

Modal Analysis of Hummingbird Inspired MAV Flapping Wings

Natural flyers are the best source of inspiration for making successful MAVs. Hummingbirds are known for their excellent flight characteristics such as long duration hovering, backward flying, high agility, etc. Giant hummingbird is chosen as the bio-inspiration for designing the wing. Wings are required to be light, strong, and fatigue resistant to be used for MAV applications. Carbon nanotubes (CNTs)/Polypropylene (PP) composite is chosen as the wing membrane material whereas carbon fiber (CF)/epoxy (E) composite is chosen for wing frame. Two types of wings are fabricated, one is CNTs/PP wing and another is CF/E frame with CNTs/PP membrane wing. Kinematics, structural dynamics, and aerodynamics are the main component of flapping flight studies. Modal analysis of fabricated wings is done using 3D visual image correlation (VIC-3D) and laser displacement sensor setup. In the end, the results of both type wings are compared with experimental results and a good correlation has been seen. The validation of results is done using Ansys.

Pollination biology of Oreocereus celsianus (Cactaceae), a columnar cactus inhabiting the high subtropical Andes

The geographical dichotomy hypothesis suggests that columnar cacti in the tropics depend primarily on bats for pollination. This dependence may to be less in the outer tropics where many columnar cactus species (or their populations) show a relatively generalized pollination system with both nocturnal (moths and bats) and diurnal pollinators (bees and hummingbirds) (geographical dichotomy hypothesis). This hypothesis has been mostly tested in the northern tropics; nonetheless, our knowledge of columnar cactus species inhabiting the southern tropics is still scarce. The aim of this project was to evaluate the pollination biology of Oreocereus celsianus, a columnar cactus with restricted distribution in the subtropical Andes, to determine if the pollination system of this cactus tends to be more generalized than specialized because of the geographical position where it occurs. Observations of frequency of visit showed that Patagona gigas (Giant Hummingbird) is the main pollinator of the flowers, visiting them when they are opening (afternoon of the first day). Bees, wasps and moths were occasional visitors of the flowers. None of them seem to act as pollinator. Autogamy, geitonogamy and xenogamy treatments produced high fruit set, showing that O. celsianus has an unusual mixed mating system. The results suggest that this Andean columnar cactus is partially specialized on hummingbirds, with most pollination service performed by a single species, and it has the capacity of selfing (‘fail-safe’ pollination system). This mixed mating system (both outcrossing and selfing) may be a response to the unpredictable environment of the Prepuna in the subtropical Andes.

Comparative Energetics of the Giant Hummingbird (Patagona gigas)

Hummingbirds (family Trochilidae) represent an extreme outcome in vertebrate physiological design and are the only birds capable of sustained hovering. The giant hummingbird (Patagona gigas) is the largest trochilid, with a mass of ~20 g, and is found over an altitudinal range from 0 to 4,500 m above sea level. We report here measurements of daily, basal, and hovering rates of oxygen consumption in the giant hummingbird; compare these values with data from smaller hummingbirds; and assess overall metabolic and allometric limits to trochilid body size. The sustained metabolic scope (i.e., the ratio of daily energy expenditure to basal metabolic rate) in the giant hummingbird is higher than that in smaller hummingbirds but lies below a proposed theoretical maximum value for endotherms. Scaling exponents in the allometric relationships for different modes of energetic expenditure were comparable, suggesting that the giant hummingbird, although a clear outlier in terms of body size, does not obviously deviate from metabolic relationships derived from other trochilid taxa.

Multi-ethnic bird guide of the sub-Antarctic forests of South America

The subantarctic forests of South America are the world’s southernmost forested ecosystems. The birds have sung in these austral forests for millions of years; the Yahgan and Mapuche peoples have handed down their bird stories from generation to generation for hundreds of years. In Multi-ethnic Bird Guide of the Subantarctic Forests of South America, Ricardo Rozzi and his collaborators present a unique combination of bird guide and cultural ethnography. The book includes entries on fifty bird species of southern Chile and Argentina, among them the Magellanic Woodpecker, Rufous-Legged Owl, Ringed Kingfisher, Buff-Necked Ibis, Giant Hummingbird, and Andean Condor. Each bird is named in Yahgan, Mapudungun, Spanish, English, and scientific nomenclature, followed by a description, full color photographs, the bird’s distribution map, habitat and lifestyle, and its history in the region. Each entry is augmented further with indigenous accounts of the bird in history and folklore. “Highly original in its approach of combining information on natural history and biodiversity with information on the region’s human cultural and linguistic diversity.”—Chris Elphick, coauthor of The Sibley Guide to Bird Life and Behavior

The Giant Hummingbird (Patagona gigas) in the Mountains of Central Argentina and a Climatic Envelope Model for its Distribution

I present the first published observations of the Giant Hummingbird (Patagona gigas) in the mountains of central Argentina. This species was recorded in early and late summer 2006 and 2007. This new range resembles other summer habitats of the species, which are in the Andes >500 km distant. A climatic envelope model configured with known locations obtained from the literature predicts a high probability of occurrence in its “new” range.

Giant Hummingbirds (Patagona gigas) Ingest Calcium-rich Minerals

We report Giant Hummingbirds (Patagona gigas), regularly and deliberately, ingesting wood ashes and slaked lime in central Chile. These two minerals have high concentrations of calcium, which may be a scarce element in the nectar-based diet of the species. Both observations occurred during the post-breeding period suggesting the birds were females ingesting calcium-rich compounds to replace minerals lost during eggshell production.

Altitudinal variation in flight mechanics and energetics of the giant Andean hummingbird

Altitudinal variation in flight mechanics and energetics of the giant Andean hummingbird

Hummingbird pollination in Salvia haenkei (Lamiaceae) lacking the typical lever mechanism

While in most Salvia species pollen is transferred by the `staminal lever mechanism', in some species the `levers' are inactive. This is also found in the bird pollinated S. haenkei from Bolivia. To understand pollen transfer in a species lacking the lever mechanism we carried out field investigations and confirmed our observations by means of morphometric measurements of both the flowers and museum skins of the observed hummingbird species. The tubular corolla forces the birds (Sappho sparganura, Colibri coruscans, Patagona gigas, Oreotrochilus adela) into a specific position thereby causing pollen transfer from the exserted pollen-sacs to the bird's feathers and bills. The staminal levers are well developed but cannot be moved because the sterile arms are closely attached to the upper face of the corolla leaving no space for any movement. We assume that the reduction of the lever mechanism reflects an adaptation to bird pollination.

DIVERSITY OF FLORAL VISITORS TO ECHINOPSIS ATACAMENSIS SUBSP. PASACANA (CACTACEAE)

Columnar cacti can be pollinated by various insect and vertebrate species, often showing either close adaptations to a single pollinator group, or a mixed pollination syndrome, depending on a variety of different animals for pollination. As pollination data for columnar cacti in South America are scarce, we investigated the spectrum, frequency, and behavior of floral visitors in Echinopsis atacamensis subsp. pasacana. We compared two habitats with differences in mean annual precipitation and human impact, finding considerably higher activity and diversity of flower visitors in the population with higher humidity. Bees, wasps, and the giant hummingbird (Patagona gigas) were shown to visit cactus flowers during the day to gather nectar or pollen. We found marked differences in the spectrum of floral visitors between both populations. In one study site, the introduced honeybee Apis mellifera removed large quantities of pollen, but seemed to be a comparatively inefficient pollinator. Additionally, first evidence for visits by nocturnal hawkmoths is provided. These results demonstrate an unspecialized floral syndrome for Echinopsis atacamensis subsp. pasacana, with both diurnal and nocturnal pollinators. Such a mixed floral syndrome is fairly widespread among columnar cacti in the northern hemisphere but was hitherto only shown for one South American species, Weberbauerocereus weberbaueri.

Direct and Indirect Effects of Nectar Robbing on the Pollinating Behavior of Patagona gigas (Trochilidae)1

ABSTRACTIn central Chile, nectar robbing of Puya coerulea (Bromeliaceae) flowers by the austral blackbird, Curaeus curaeus, had a direct impact on the plant via removal of floral resources and, in some cases, damage or even destruction of flowers. These robbing visits also likely had an indirect impact on plant fitness due to the decreased rate of legitimate visits by the hummingbird Patagona gigas to inflorescences with many robbed flowers. The proportion of flowers within an inflorescence visited by P. gigas was inversely proportional to the ratio of robbed flowers.

Fernando I. Ortiz‐Crespo (1942–2001)

Fernando I. Ortiz‐Crespo (1942–2001)

Bat and hummingbird pollination of an AUTOTETRAPLOID COLUMNAR CACTUS, Weberbauerocereus weberbaueri (Cactaceae)

I present data on flower morphology, pollination, breeding system, and genetic diversity of the columnar cactus Weber‐bauerocereus weberbaueri at 2500 m elevation in southwestern Peru. Weberbauerocereus weberbaueri is a self‐compatible columnar cactus that is visited and pollinated by one species of rare endemic bat, Platalina genovensium, and two species of hummingbirds, Patagona gigas and Rhodopis vesper. W. weberbaueri exhibits pronounced interplant variation in floral color and size, and flowers exhibit traits corresponding to both bat and hummingbird pollination syndromes. Starch‐gel electrophoresis of flower bud tissue indicated that W. weberbaueri is an autotetraploid and that genetic diversity (Hep = 0.257) of the study population was high relative to diploid plants but similar to other tetraploid species. Initial fruit set from pollinator exclusion experiments conducted in 1991 and 1993, at the onset of and after a drought associated with the El Niño event of 1991–1992, revealed that bats were the most important pollinators in 1991, but that hummingbirds and diurnal insects were most important in 1993. In both years, however, autogamy and lepidopteran larval infestation of fruits reduced differences in mature fruit production among pollinator exclusion treatments so that differences in mature fruit set were not statistically significant. Reduced bat pollination in 1993 is attributed to the reduced abundance of bats at the study site during a drought caused by El Niño. I hypothesize that interaction among several factors, including tetraploidy, autogamy, larval infestation of developing fruits, and variation in pollinator abundance, may not result in strong selection for a bat vs. hummingbird floral morph, thus allowing the persistence of floral variation in this cactus.

Floral Nectary Structure and Nectar Composition in Eccremocarpus scaber (Bignoniaceae), a Hummingbird-Pollinated Plant of Central Chile

Surface features, anatomy, and ultrastructure of the floral nectary of Eccremocarpus scaber (Bignoniaceae), pollinated predominantly by the largest-known hummingbird (Patagona gigas gigas), were studied together with nectar sugar content and secretion rate. The annular disk nectary comprises epidermis, secretory and ground parenchyma with intercellular spaces, and branched vascular bundles terminating in the secretory parenchyma where only phloem is found. Amyloplasts and vacuoles increase in size throughout development, the latter becoming sites of organelle degradation. Transferlike cells in nectary phloem and P-proteinlike fibrillar material in phloem parenchyma were observed. Flowers produced around 32 μl of nectar (mostly after anthesis) with 11 mg of sugar composed of fructose, glucose, sucrose, and maltose in a ratio of 0.34:0.32:0.17:0.17. Morphological studies as well as the presence of maltose and glucose in nectar suggest storage of the originally phloem-derived sugars as starch with its subsequent hydrolysis. The low sucrose/hexose ratio (0.25) and high nectary secretion force (nectar per flower biomass) observed places E. scaber close to large-bodied bat-pollinated plants. A hypothesis based on nectar origin and nectar secretion is advanced to explain pollinator-correlated variation in sucrose/hexose ratio.