Journal articles: 'Flightless birds'

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Maderspacher, Florian. "Flightless birds." Current Biology 32, no. 20 (October 2022): R1155—R1162. http://dx.doi.org/10.1016/j.cub.2022.09.039.

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Wright, Natalie A., David W. Steadman, and Christopher C. Witt. "Predictable evolution toward flightlessness in volant island birds." Proceedings of the National Academy of Sciences 113, no. 17 (April 11, 2016): 4765–70. http://dx.doi.org/10.1073/pnas.1522931113.

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Birds are prolific colonists of islands, where they readily evolve distinct forms. Identifying predictable, directional patterns of evolutionary change in island birds, however, has proved challenging. The “island rule” predicts that island species evolve toward intermediate sizes, but its general applicability to birds is questionable. However, convergent evolution has clearly occurred in the island bird lineages that have undergone transitions to secondary flightlessness, a process involving drastic reduction of the flight muscles and enlargement of the hindlimbs. Here, we investigated whether volant island bird populations tend to change shape in a way that converges subtly on the flightless form. We found that island bird species have evolved smaller flight muscles than their continental relatives. Furthermore, in 366 populations of Caribbean and Pacific birds, smaller flight muscles and longer legs evolved in response to increasing insularity and, strikingly, the scarcity of avian and mammalian predators. On smaller islands with fewer predators, birds exhibited shifts in investment from forelimbs to hindlimbs that were qualitatively similar to anatomical rearrangements observed in flightless birds. These findings suggest that island bird populations tend to evolve on a trajectory toward flightlessness, even if most remain volant. This pattern was consistent across nine families and four orders that vary in lifestyle, foraging behavior, flight style, and body size. These predictable shifts in avian morphology may reduce the physical capacity for escape via flight and diminish the potential for small-island taxa to diversify via dispersal.

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Hume, Julian P., and David Martill. "Repeated evolution of flightlessness in Dryolimnas rails (Aves: Rallidae) after extinction and recolonization on Aldabra." Zoological Journal of the Linnean Society 186, no. 3 (May 8, 2019): 666–72. http://dx.doi.org/10.1093/zoolinnean/zlz018.

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AbstractThe Aldabra rail, Dryolimnas cuvieri subsp. aldabranus, endemic to the Aldabra Atoll, Seychelles, is the last surviving flightless bird in the Indian Ocean. Aldabra has undergone at least one major, total inundation event during an Upper Pleistocene (Tarantian age) sea-level high-stand, resulting in the loss of all terrestrial fauna. A flightless Dryolimnas has been identified from two temporally separated Aldabran fossil localities, deposited before and after the inundation event, providing irrefutable evidence that a member of Rallidae colonized the atoll, most likely from Madagascar, and became flightless independently on each occasion. Fossil evidence presented here is unique for Rallidae and epitomizes the ability of birds from this clade to successfully colonize isolated islands and evolve flightlessness on multiple occasions.

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Johnston, Peter, and Kieren J. Mitchell. "Contrasting Patterns of Sensory Adaptation in Living and Extinct Flightless Birds." Diversity 13, no. 11 (October 26, 2021): 538. http://dx.doi.org/10.3390/d13110538.

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Avian cranial anatomy is constrained by the competing (or complementary) requirements and costs of various facial, muscular, sensory, and central neural structures. However, these constraints may operate differently in flighted versus flightless birds. We investigated cranial sense organ morphology in four lineages of flightless birds: kiwi (Apteryx), the Kakapo (Strigops habroptilus), and the extinct moa (Dinornithiformes) from New Zealand; and the extinct elephant birds from Madagascar (Aepyornithidae). Scleral ring and eye measurements suggest that the Upland Moa (Megalapteryx didinus) was diurnal, while measurements for the Kakapo are consistent with nocturnality. Kiwi are olfactory specialists, though here we postulate that retronasal olfaction is the dominant olfactory route in this lineage. We suggest that the Upland Moa and aepyornithids were also olfactory specialists; the former additionally displaying prominent bill tip sensory organs implicated in mechanoreception. Finally, the relative size of the endosseous cochlear duct revealed that the Upland Moa had a well-developed hearing sensitivity range, while the sensitivity of the kiwi, Kakapo, and aepyornithids was diminished. Together, our results reveal contrasting sensory strategies among extant and extinct flightless birds. More detailed characterisation of sensory capacities and cranial anatomy in extant birds may refine our ability to make accurate inferences about the sensory capacities of fossil taxa.

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Feneck, Eleanor M., Sorrel R. B. Bickley, and Malcolm P. O. Logan. "Embryonic Development of the Avian Sternum and Its Morphological Adaptations for Optimizing Locomotion." Diversity 13, no. 10 (September 29, 2021): 481. http://dx.doi.org/10.3390/d13100481.

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The sternum is part of the forelimb appendicular skeleton found in most terrestrial vertebrates and has become adapted across tetrapods for distinctive modes of locomotion. We review the regulatory mechanisms underlying sternum and forelimb development and discuss the possible gene expression modulation that could be responsible for the sternal adaptations and associated reduction in the forelimb programme found in flightless birds. In three phylogenetically divergent vertebrate lineages that all undertake powered flight, a ventral extension of the sternum, named the keel, has evolved independently, most strikingly in volant birds. In flightless birds, however, the sternal keel is absent, and the sternum is flattened. We review studies in a variety of species that have analysed adaptations in sterna morphology that are related to the animal’s mode of locomotion on land, in the sky and in water.

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Stokoe, William C. "On Cats’ Eyes, Flightless Birds & “Home Signs”." Sign Language Studies 1087, no. 1 (1995): 175–84. http://dx.doi.org/10.1353/sls.1995.0022.

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Kavanau, J. Lee. "Secondarily flightless birds or Cretaceous non-avian theropods?" Medical Hypotheses 74, no. 2 (February 2010): 275–76. http://dx.doi.org/10.1016/j.mehy.2009.09.015.

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Agnolin, Federico L. "Reappraisal on the Phylogenetic Relationships of the Enigmatic Flightless Bird (Brontornis burmeisteri) Moreno and Mercerat, 1891." Diversity 13, no. 2 (February 20, 2021): 90. http://dx.doi.org/10.3390/d13020090.

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The fossil record of birds in South America is still very patchy. One of the most remarkable birds found in Miocene deposits from Patagonia is Brontornis burmeisteri Moreno and Mercerat, 1891. This giant flightless bird is known by multiple incomplete specimens that represent a few portions of the skeleton, mainly hindlimb bones. Since the XIX century, Brontornis was considered as belonging to or closely related to phorusrhacoid birds. In contrast to previous work, by the end of 2000 decade it was proposed that Brontornis belongs to Galloanserae. This proposal was recently contested based on a large dataset including both phorusrhacoids and galloanserine birds, that concluded Brontornis was nested among cariamiform birds, and probably belonged to phorusrhacoids. The aim of the present contribution is to re-evaluate the phylogenetic affinities of Brontornis. Based on modified previous datasets, it is concluded that Brontornis does belong to Galloanserae, and that it represents a member of a largely unknown radiation of giant graviportal birds from South America.

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Hambler, C., J. Newing, and K. Hambler. "Population monitoring for the flightless rail Dryolimnas cuvieri aldabranus." Bird Conservation International 3, no. 4 (December 1993): 307–18. http://dx.doi.org/10.1017/s0959270900002586.

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SummaryThe last flightless bird of the western Indian Ocean, Dryolimnas cuvieri aldabranus survives only on Aldabra. Its population numbered some 8,000 in 1973–1976. Surveys suggest numbers remained roughly constant between 1968 and 1988 (with a fluctuation of only 4% in responses to call playback between 1983 and 1988), but distribution continued to contract. Longevity can reach over 8.5 years (but is probably lower on average), and some birds remain within 100 m of the site of ringing for at least five years. Feral predators remain a threat, and captive populations are recommended. The monitoring procedure may have value for other Gruiformes.

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Canoville, Aurore, Anusuya Chinsamy, and Delphine Angst. "New Comparative Data on the Long Bone Microstructure of Large Extant and Extinct Flightless Birds." Diversity 14, no. 4 (April 15, 2022): 298. http://dx.doi.org/10.3390/d14040298.

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Here, we investigate whether bone microanatomy can be used to infer the locomotion mode (cursorial vs. graviportal) of large terrestrial birds. We also reexamine, or describe for the first time, the bone histology of several large extant and extinct flightless birds to (i) document the histovariability between skeletal elements of the hindlimb; (ii) improve our knowledge of the histological diversity of large flightless birds; (iii) and reassess previous hypotheses pertaining to the growth strategies of modern palaeognaths. Our results show that large extinct terrestrial birds, inferred as graviportal based on hindlimb proportions, also have thicker diaphyseal cortices and/or more bony trabeculae in the medullary region than cursorial birds. We also report for the first time the occurrence of growth marks (not associated with an outer circumferential layer-OCL) in the cortices of several extant ratites. These observations support earlier hypotheses that flexible growth patterns can be present in birds when selection pressures for rapid growth within a single year are absent. We also document the occurrence of an OCL in several skeletally mature ratites. Here, the high incidence of pathologies among the modern species is attributed to the fact that these individuals were probably long-lived zoo specimens.

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Torres, Christopher R., and Julia A. Clarke. "Nocturnal giants: evolution of the sensory ecology in elephant birds and other palaeognaths inferred from digital brain reconstructions." Proceedings of the Royal Society B: Biological Sciences 285, no. 1890 (October 31, 2018): 20181540. http://dx.doi.org/10.1098/rspb.2018.1540.

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The recently extinct Malagasy elephant birds (Palaeognathae, Aepyornithiformes) included the largest birds that ever lived. Elephant bird neuroanatomy is understudied but can shed light on the lifestyle of these enigmatic birds. Palaeoneurological studies can provide clues to the ecologies and behaviours of extinct birds because avian brain shape is correlated with neurological function. We digitally reconstruct endocasts of two elephant bird species, Aepyornis maximus and A. hildebrandti , and compare them with representatives of all major extant and recently extinct palaeognath lineages. Among palaeognaths, we find large olfactory bulbs in taxa generally occupying forested environments where visual cues used in foraging are likely to be limited. We detected variation in olfactory bulb size among elephant bird species, possibly indicating interspecific variation in habitat. Elephant birds exhibited extremely reduced optic lobes, a condition also observed in the nocturnal kiwi. Kiwi, the sister taxon of elephant birds, have effectively replaced their visual systems with hyperdeveloped olfactory, somatosensory and auditory systems useful for foraging. We interpret these results as evidence for nocturnality among elephant birds. Vision was likely deemphasized in the ancestor of elephant birds and kiwi. These results show a previously unreported trend towards decreased visual capacity apparently exclusive to flightless, nocturnal taxa endemic to predator-depauperate islands.

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Chan, Nicholas R. "Phylogenetic variation in hind-limb bone scaling of flightless theropods." Paleobiology 43, no. 1 (November 24, 2016): 129–43. http://dx.doi.org/10.1017/pab.2016.32.

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AbstractThe robusticity of the weight-bearing limbs of large terrestrial animals is expected to increase at a more rapid rate than in their smaller relatives. This scaling has been hypothesized to allow large species to maintain stresses in the limb bones that are similar to those seen in smaller ones. Curvilinear scaling has previously been found in mammals and nonavian theropods but has not been demonstrated in birds. In this study, polynomial regressions of leg-bone length and circumference in terrestrial flightless birds were carried out to test for a relationship similar to that seen in nonavian theropods. Flightless birds exhibit curvilinear scaling, with the femora of large taxa becoming thicker relative to length at a greater rate than in smaller taxa. Evidence was found for nonlinear scaling in the leg bones of nonavian theropods. However, unlike in avians, there is also phylogenetic variation between taxonomic groups, with tyrannosaur leg bones in particular scaling differently than other groups. Phylogenetically corrected quadratic regressions and separate analyses of taxonomic groupings found little phylogenetic variation in flightless birds. It is suggested here that the nonlinear scaling seen in avian femora is due to the need to maintain the position of the knee under a more anterior center of mass, thereby restricting femoral length. The femur of nonavian theropods is not so constrained, with greater variability of the linear scaling relationships between clades. Phylogenetic variation in limb-bone scaling may broaden the errors for mass-predictive scaling equations based on limb-bone measurements of nonavian theropods.

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Buffetaut, Eric, and Delphine Angst. "An Introduction to Evolution and Palaeobiology of Flightless Birds." Diversity 14, no. 4 (April 15, 2022): 296. http://dx.doi.org/10.3390/d14040296.

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Brown, Richard E., and David K. Saunders. "Regulated changes in body mass and muscle mass in molting Blue-winged Teal for an early return to flight." Canadian Journal of Zoology 76, no. 1 (January 1, 1998): 26–32. http://dx.doi.org/10.1139/z97-164.

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During the breeding season, Blue-winged Teal (Anas discors) undergo cyclic changes in body mass (Mb) and pectoral- and leg-muscle mass coincident with the simultaneous molt of all flight feathers. These conformational changes cannot be attributed to nutritional or metabolic demands, nor can they be a use-disuse phenomenon. A reduction of >>18% in body mass from premolt values produces wing loadings (Mb/wing area) nearly equal to those seen premolt, allowing these birds to regain flight capability, although the flight feathers are <<75% of premolt length and area. A reduction of >>30% in flight-muscle mass represents about half of the total reduction in Mb; however, the lowest power necessary for flight, calculated for five different periods during the breeding season, is found at 75% of feather regrowth. Reduction in Mb coupled with a >>40% increase in leg-muscle mass during the flightless period should permit these birds to achieve higher swimming speeds. The temporal and mechanical relationships of these conformation adjustments suggest that they are programmed or regulated to (i) permit the earliest possible return to flight after the molt-related flightless period and (ii) provide for faster predator-avoidance speeds across or under the water during the flightless period.

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Hume, Julian Pender, and Anthony S. Cheke. "The white dodo of Réunion Island: unravelling a scientific and historical myth." Archives of Natural History 31, no. 1 (April 2004): 57–79. http://dx.doi.org/10.3366/anh.2004.31.1.57.

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ABSTRACT: The supposed white dodo of Réunion Island (Indian Ocean) arose from a merging of travellers' tales of large whitish birds with some enigmatic paintings of white dodos painted in mid- to late- seventeenth-century Holland. Sub-fossil bone discoveries in the 1970s onwards revealed that the bird which travellers called a solitaire was a large, quasi-flightless ibis, while the Dutch paintings turn out to have been based on a much earlier picture by Roelant Savery of a whitish specimen of a Mauritius dodo (Raphus cucullatus), painted in Prague around 1611. Savery's dodo images impact on this story at various points and are discussed in detail. There are geological reasons for believing dodos, evolving in Mauritius, would have been already flightless before Réunion emerged and hence could not have colonised that more recent volcanic island. No contemporary images are known of the Réunion solitaire (the ibis, Threskiornis solitarius) and no specimens were brought to Europe alive or dead.

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Longrich, Nicholas R., and Storrs L. Olson. "The bizarre wing of the Jamaican flightless ibis Xenicibis xympithecus : a unique vertebrate adaptation." Proceedings of the Royal Society B: Biological Sciences 278, no. 1716 (January 5, 2011): 2333–37. http://dx.doi.org/10.1098/rspb.2010.2117.

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Birds have frequently evolved to exploit insular environments by becoming adapted to a terrestrial lifestyle and losing the ability to fly, usually via reducing the wings and pectoral girdle. The enigmatic flightless ibis Xenicibis xympithecus (Threskiornithidae) from the Quaternary of Jamaica provides a rare example of flight loss in ibises. We report on previously undescribed fossils of Xenicibis , and show that the wing differed radically from that of all other birds, flightless or volant. The metacarpus is elongate, grotesquely inflated and has extremely thick walls; phalanges are short and block-like; the radius is distally expanded; and the humerus is elongate. The furcula, coracoid and sternum are all well developed. We propose that the elongate forelimb and massive hand functioned in combat as a jointed club or flail. This hypothesis is supported by the morphology of the carpometacarpus, by features permitting rapid extension of the wing and by the presence of fractures in wing bones. Although other birds use the wings as weapons, none resemble Xenicibis , which represents a unique and extraordinary morphological solution to this functional problem. Xenicibis strikingly illustrates how similar selective pressures, acting on a similar starting point, can result in novel outcomes.

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Olson, Storrs L. "Magnificent Mihirungs. The Colossal Flightless Birds of the Australian Dreamtime." Auk 122, no. 1 (2005): 367. http://dx.doi.org/10.1642/0004-8038(2005)122[0367:mmtcfb]2.0.co;2.

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CLOUT, M. N., and J. L. CRAIG. "The conservation of critically endangered flightless birds in New Zealand." Ibis 137 (June 28, 2008): S181—S190. http://dx.doi.org/10.1111/j.1474-919x.1995.tb08440.x.

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Olson, Storrs L. "Magnificent Mihirungs. The Colossal Flightless Birds of the Australian Dreamtime." Auk 122, no. 1 (January 1, 2005): 367–71. http://dx.doi.org/10.1093/auk/122.1.367.

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Caspermeyer, J. "Scientists Reveal New Picture in the Evolution of Flightless Birds." Molecular Biology and Evolution 31, no. 7 (May 24, 2014): 1939. http://dx.doi.org/10.1093/molbev/msu165.

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Milius, Susan. "Life & evolution: Flightless birds' history upset by ancient DNA." Science News 185, no. 13 (June 17, 2014): 15. http://dx.doi.org/10.1002/scin.5591851315.

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Maina, John N., and Christopher Nathaniel. "A qualitative and quantitative study of the lung of an ostrich,Struthio camelus." Journal of Experimental Biology 204, no. 13 (July 1, 2001): 2313–30. http://dx.doi.org/10.1242/jeb.204.13.2313.

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SUMMARYThe ostrich lung, with its lack of interparabronchial septa, the presence of very shallow atria and exceptional morphometric refinement, structurally resembles those of small, energetic flying birds, whereas it also displays features characteristic of the flightless ratites in which the neopulmo is relatively poorly developed and a segmentum accelerans may be generally lacking. The large size of the bronchial system of the ostrich may help explain the unique shifts in the airflow pathways that must occur from resting to panting breathing, explaining its insensitivity to acid–base imbalance of the blood during sustained panting under thermal stress. The mass-specific volume of the lung is 39.1 cm3kg−1 and the volume density of the exchange tissue is remarkably high (78.31%). The blood–gas (tissue) barrier is relatively thick (0.56μm) but the plasma layer is very thin (0.14μm). In this flightless ratite bird, the mass-specific surface area of the tissue barrier (30.1 cm2g−1), the mass-specific anatomical diffusing capacity of the tissue barrier for oxygen (0.0022mlO2s−1Pa−1kg−1), the mass-specific volume of pulmonary capillary blood (6.25 cm3kg−1) and the mass-specific total anatomical diffusing capacity for oxygen (0.00073mlO2s−1Pa−1kg−1) are equivalent to or exceed those of much smaller highly aerobic volant birds. The distinctive morphological and morphometric features that seem to occur in the ostrich lung may explain how it achieves and maintains high aerobic capacities and endures long thermal panting without experiencing respiratory alkalosis.

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F. Recher, H. "Guide to the Birds of Fiji and Western Polynesia." Pacific Conservation Biology 9, no. 3 (2003): 234. http://dx.doi.org/10.1071/pc030234.

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FEW taxa have suffered at the expansion of humanity to the extent of the birds of Pacific Islands. Of the 130 or so birds to become extinct as a consequence of European exploration and colonization of the Pacific, most were island birds and most were flightless rails. Not so well understood is the scale of extinctions that accompanied pre-European colonization of the Pacific islands. Only now is the paleontological record revealing the richness of the lost Pacific avifauna much of which can be put on a par with the loss of moas from New Zealand and the Dodo Raphus cucullatus from Mauritius in the Indian Ocean.

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Sayol, F., M. J. Steinbauer, T. M. Blackburn, A. Antonelli, and S. Faurby. "Anthropogenic extinctions conceal widespread evolution of flightlessness in birds." Science Advances 6, no. 49 (December 2020): eabb6095. http://dx.doi.org/10.1126/sciadv.abb6095.

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Human-driven extinctions can affect our understanding of evolution, through the nonrandom loss of certain types of species. Here, we explore how knowledge of a major evolutionary transition—the evolution of flightlessness in birds—is biased by anthropogenic extinctions. Adding data on 581 known anthropogenic extinctions to the extant global avifauna increases the number of species by 5%, but quadruples the number of flightless species. The evolution of flightlessness in birds is a widespread phenomenon, occurring in more than half of bird orders and evolving independently at least 150 times. Thus, we estimate that this evolutionary transition occurred at a rate four times higher than it would appear based solely on extant species. Our analysis of preanthropogenic avian diversity shows how anthropogenic effects can conceal the frequency of major evolutionary transitions in life forms and highlights the fact that macroevolutionary studies with only small amounts of missing data can still be highly biased.

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LAWRENCE, NATALIE. "Assembling the dodo in early modern natural history." British Journal for the History of Science 48, no. 3 (February 23, 2015): 387–408. http://dx.doi.org/10.1017/s0007087415000011.

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AbstractThis paper explores the assimilation of the flightless dodo into early modern natural history. The dodo was first described by Dutch sailors landing on Mauritius in 1598, and became extinct in the 1680s or 1690s. Despite this brief period of encounter, the bird was a popular subject in natural-history works and a range of other genres. The dodo will be used here as a counterexample to the historical narratives of taxonomic crisis and abrupt shifts in natural history caused by exotic creatures coming to Europe. Though this bird had a bizarre form, early modern naturalists integrated the dodo and other flightless birds through several levels of conceptual categorization, including the geographical, morphological and symbolic. Naturalists such as Charles L'Ecluse produced a set of typical descriptive tropes that helped make up the European dodo. These long-lived images were used for a variety of symbolic purposes, demonstrated by the depiction of the Dutch East India enterprise in Willem Piso's 1658 publication. The case of the dodo shows that, far from there being a dramatic shift away from emblematics in the seventeenth century, the implicit symbolic roles attributed to exotic beasts by naturalists constructing them from scant information and specimens remained integral to natural history.

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Sivak, J. G., and H. C. Howland. "Refractive state of the eye of the brown kiwi (Apteryx australis)." Canadian Journal of Zoology 65, no. 11 (November 1, 1987): 2833–35. http://dx.doi.org/10.1139/z87-431.

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Kiwis are flightless, nocturnal birds with relatively small rudimentary eyes. Numerous reports indicate that these birds are myopic. Refractive measurements, carried out by retinoscopy and photorefraction, on two brown kiwis (Apteryx australis) show that they are hyperopic by amounts varying between 2.3 and 7.0 diopters. This variation is presumably an indication of accommodative ability. Since the kiwi eye is relatively small and since the refractive measurements may be based on reflection from the vitreous surface of the retina, all or part of the hyperopia measured may be artifactual.

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Hecht, Jeff. "Losing their dino tail put limit on size of flightless birds." New Scientist 220, no. 2944 (November 2013): 17. http://dx.doi.org/10.1016/s0262-4079(13)62724-4.

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Cubo, Jorge, and Wallace Arthur. "Patterns of correlated character evolution in flightless birds: a phylogenetic approach." Evolutionary Ecology 14, no. 8 (November 2000): 693–702. http://dx.doi.org/10.1023/a:1011695406277.

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Mayr, Gerald. "Of elephant-, thunder-, and terror birds: The allure of flightless giants." Acta Zoologica 100, no. 2 (February 16, 2018): 218–19. http://dx.doi.org/10.1111/azo.12250.

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Cheke, Anthony S., and Jolyon C. Parish. "The Dodo and the Red Hen, A Saga of Extinction, Misunderstanding, and Name Transfer: A Review." Quaternary 3, no. 1 (February 18, 2020): 4. http://dx.doi.org/10.3390/quat3010004.

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The chronology of observations of two extinct flightless birds in 17th century Mauritius, the dodo (Raphus cucullatus) and the red hen (Aphanapteryx bonasia), and what names or descriptions were used for them, is re-examined. It was concluded that the balance of probabilities is strongly against birds called dodaarsen without descriptions in the 1680s being dodos rather than red hens. The dodo had disappeared earlier due to predation by pigs, but a hiatus in settlement broke observational continuity, yet folklore preserved the name and transferred it to the red hen. The dodo’s extinction thus happened unobserved.

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Worthy, Trevor H., Federico J. Degrange, Warren D. Handley, and Michael S. Y. Lee. "The evolution of giant flightless birds and novel phylogenetic relationships for extinct fowl (Aves, Galloanseres)." Royal Society Open Science 4, no. 10 (October 2017): 170975. http://dx.doi.org/10.1098/rsos.170975.

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The extinct dromornithids, gastornithids and phorusrhacids are among the most spectacular birds to have ever lived, with some giants exceeding 500 kg. The affinities and evolution of these and other related extinct birds remain contentious, with previous phylogenetic analyses being affected by widespread convergence and limited taxon sampling. We address these problems using both parsimony and tip-dated Bayesian approaches on an expansive taxon set that includes all key extinct flightless and flighted (e.g. Vegavis and lithornithids) forms, an extensive array of extant fowl (Galloanseres), representative Neoaves and palaeognaths. The Paleogene volant Lithornithidae are recovered as stem palaeognaths in the Bayesian analyses. The Galloanseres comprise four clades inferred to have diverged in the Late Cretaceous on Gondwana. In addition to Anseriformes and Galliformes, we recognize a robust new clade (Gastornithiformes) for the giant flightless Dromornithidae (Australia) and Gastornithidae (Eurasia, North America). This clade exhibits parallels to ratite palaeognaths in that flight presumably was lost and giant size attained multiple times. A fourth clade is represented by the Cretaceous Vegavis (Antarctica), which was strongly excluded from Anseriformes; thus, a crucial molecular calibration point needs to be reconsidered. The presbyornithids Wilaru (Australia) and Presbyornis (Northern Hemisphere) are robustly found to be the sister group to Anatoidea (Anseranatidae + Anatidae), a relatively more basal position than hitherto recognized. South America's largest bird, Brontornis , is not a galloansere, but a member of Neoaves related to Cariamiformes; therefore, giant Galloanseres remain unknown from this continent. Trait analyses showed that while gigantism and flightlessness evolved repeatedly in groups, diet is constrained by phylogeny: all giant Galloanseres and palaeognaths are herbivores or mainly herbivorous, and giant neoavians are zoophagous or omnivorous.

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Fromm, Amir, Shai Meiri, and Jenny McGuire. "Big, flightless, insular and dead: Characterising the extinct birds of the Quaternary." Journal of Biogeography 48, no. 9 (July 3, 2021): 2350–59. http://dx.doi.org/10.1111/jbi.14206.

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Bramley, Gary N., and Clare J. Veltman. "Failure of translocated, captive-bred North Island Weka Gallirallus australis greyi to establish a new population." Bird Conservation International 8, no. 2 (June 1998): 195–204. http://dx.doi.org/10.1017/s0959270900003269.

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SummarySince i960 107 translocations of wild-caught Weka (genus Gallirallus) have occurred in New Zealand. Only four of these Weka liberations resulted in a population that persisted for more than 10 years and only one was successful on the North Island (the resultant population is now believed extinct). The reason for these failures was not known. In 1991 members of the Royal Forest and Bird Protection Society commenced breeding North Island Weka Gallirallus australis greyi in captivity for another liberation. Between 1992 and 1996 101 weka were released. We used radio telemetry to follow the fates of the first 17 Weka released in the Karangahake Gorge, near Paeroa, North Island, New Zealand to determine possible outcomes of the liberation. Only one of the 17 birds released survived until 242 days post release. Most newly released Weka were killed by predators, mainly dogs. Future Weka and flightless rail introductions should occur only in areas where predators are being removed to allow survival of released birds and production of young to exceed mortality.

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van de Wetering, Debbie, and Fred Cooke. "Body Weight and Feather Growth of Male Barrow's Goldeneye During Wing Molt." Condor 102, no. 1 (February 1, 2000): 228–31. http://dx.doi.org/10.1093/condor/102.1.228.

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Abstract We studied the timing, duration, and rate of wing molt of male Barrow's Goldeneye (Bucephala islandica). The mean daily change in primary feather length was 2.6%, which is consistent with rates reported for other waterfowl species. The mean length of the flightless period was 31 days (range: 27–34 days), excluding the pre-shedding interval. Wing molt extended from early July to mid-September. Peak wing molt occurred between 20 July and 23 August. The mean body weight of adult males decreased significantly during wing molt. Heavier birds had greater remigial growth rates and experienced more substantial declines in body weight than lighter birds, suggesting that body reserves may be used to increase the rate of remigial growth.

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Mayr, Gerald. "Osteology and phylogenetic affinities of the middle Eocene North AmericanBathornis grallator—one of the best represented, albeit least known Paleogene cariamiform birds (seriemas and allies)." Journal of Paleontology 90, no. 2 (March 2016): 357–74. http://dx.doi.org/10.1017/jpa.2016.45.

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AbstractBathornis(“Neocathartes”)grallator(Wetmore, 1944) from the middle Eocene of Wyoming is based on a partial skeleton, which is the most substantial record of the North American Bathornithidae and one of the most complete fossils of a Paleogene stem group representative of the Cariamiformes. So far, however, an assessment of the evolutionary significance of this important fossil has been hampered by the limited published osteological data. Moreover, cariamiform affinities ofB.grallatorand its true “genus”-level identity were recognized after the last comprehensive revision of the Bathornithidae, and some of its features were incorrectly portrayed in the original description. Here, theB.grallatorholotype is restudied and the taxonomic composition and phylogenetic affinities of bathornithids are revised. It is suggested to restrict Bathornithidae to the taxonBathornis, from which the putative bathornithidParacraxdiffers in numerous features, with even cariamiform affinities of this latter taxon not having been established beyond doubt.B.grallatorwas a flightless bird and has recently been hypothesized to be the sister taxon of the likewise flightless South American Phorusrhacidae. The present analysis, however, supports a position outside a clade including Phorusrhacidae and Cariamidae (the cariamiform crown clade). Owing to their terrestrial way of living, Cariamiformes appear to have been prone to a loss of flight capabilities.B.grallatorshows close similarities to a flightless cariamiform bird from the Paleogene of Europe, but the phylogenetic significance of this resemblance is difficult to assess owing to the limited material known of the latter species.

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Sackton, Timothy B., Phil Grayson, Alison Cloutier, Zhirui Hu, Jun S. Liu, Nicole E. Wheeler, Paul P. Gardner, et al. "Convergent regulatory evolution and loss of flight in paleognathous birds." Science 364, no. 6435 (April 4, 2019): 74–78. http://dx.doi.org/10.1126/science.aat7244.

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A core question in evolutionary biology is whether convergent phenotypic evolution is driven by convergent molecular changes in proteins or regulatory regions. We combined phylogenomic, developmental, and epigenomic analysis of 11 new genomes of paleognathous birds, including an extinct moa, to show that convergent evolution of regulatory regions, more so than protein-coding genes, is prevalent among developmental pathways associated with independent losses of flight. A Bayesian analysis of 284,001 conserved noncoding elements, 60,665 of which are corroborated as enhancers by open chromatin states during development, identified 2355 independent accelerations along lineages of flightless paleognaths, with functional consequences for driving gene expression in the developing forelimb. Our results suggest that the genomic landscape associated with morphological convergence in ratites has a substantial shared regulatory component.

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Patak, A., and J. Baldwin. "STRUCTURAL AND METABOLIC CHARACTERIZATION OF THE MUSCLES USED TO POWER RUNNING IN THE EMU (DROMAIUS NOVAEHOLLANDIAE), A GIANT FLIGHTLESS BIRD." Journal of Experimental Biology 175, no. 1 (February 1, 1993): 233–49. http://dx.doi.org/10.1242/jeb.175.1.233.

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The emu is a giant flightless bird, capable of sustained high-speed running. Anatomical, histochemical and biochemical properties of the lower leg muscles used to power running were investigated. The gastrocnemius is the largest muscle in the emu leg. It has a short inelastic tendon and contains only fast fibres. It is the major power-producing muscle of the lower leg, with a greater capacity than the digital flexor muscles for bursts of high work output. In marked contrast, the digital flexors have long elastic tendons and contain both fast and slow muscle fibres. It is proposed that these muscles, rather than the gastrocnemius, are responsible for maintaining posture and that they facilitate elastic energy storage and retrieval in their tendons during running. In comparison with equivalent muscles of flying and diving birds, emu lower leg muscles display features consistent with greater power output during both short burst and endurance running. The emu muscles are more massive relative to body size, and the gastrocnemii of other birds invariably contain slow fibres This study illustrates some of the similarities as well as differences between muscles used during flying and running. Capacities for sustained high-energy work appear to be similar in flying birds and running emus as judged from (1) the muscle masses used during locomotion when expressed as a proportion of total body mass and (2) muscle fibre type compositions and their potential for fuel catabolism. The lower creatine kinase activity in emu leg muscles could be attributed to higher energy demands during the initial stages of lift-off for flight.

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Kapusta, Aurélie, Alexander Suh, and Cédric Feschotte. "Dynamics of genome size evolution in birds and mammals." Proceedings of the National Academy of Sciences 114, no. 8 (February 8, 2017): E1460—E1469. http://dx.doi.org/10.1073/pnas.1616702114.

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Genome size in mammals and birds shows remarkably little interspecific variation compared with other taxa. However, genome sequencing has revealed that many mammal and bird lineages have experienced differential rates of transposable element (TE) accumulation, which would be predicted to cause substantial variation in genome size between species. Thus, we hypothesize that there has been covariation between the amount of DNA gained by transposition and lost by deletion during mammal and avian evolution, resulting in genome size equilibrium. To test this model, we develop computational methods to quantify the amount of DNA gained by TE expansion and lost by deletion over the last 100 My in the lineages of 10 species of eutherian mammals and 24 species of birds. The results reveal extensive variation in the amount of DNA gained via lineage-specific transposition, but that DNA loss counteracted this expansion to various extents across lineages. Our analysis of the rate and size spectrum of deletion events implies that DNA removal in both mammals and birds has proceeded mostly through large segmental deletions (>10 kb). These findings support a unified “accordion” model of genome size evolution in eukaryotes whereby DNA loss counteracting TE expansion is a major determinant of genome size. Furthermore, we propose that extensive DNA loss, and not necessarily a dearth of TE activity, has been the primary force maintaining the greater genomic compaction of flying birds and bats relative to their flightless relatives.

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Sedghi, Majid, Ahmad Saboonchi, and Mohammad Ghane. "AN EXPERIMENTAL STUDY ON THE PERMEABILITY OF FLYING AND FLIGHTLESS BIRDS’ CONTOUR FEATHERS." Journal of Porous Media 21, no. 13 (2018): 1347–57. http://dx.doi.org/10.1615/jpormedia.2019028889.

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Bell, Alyssa, and Luis M. Chiappe. "The Hesperornithiformes: A Review of the Diversity, Distribution, and Ecology of the Earliest Diving Birds." Diversity 14, no. 4 (April 1, 2022): 267. http://dx.doi.org/10.3390/d14040267.

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The Hesperornithiformes (sometimes referred to as Hesperornithes) are the first known birds to have adapted to a fully aquatic lifestyle, appearing in the fossil record as flightless, foot-propelled divers in the early Late Cretaceous. Their known fossil record—broadly distributed across the Northern Hemisphere—shows a relatively rapid diversification into a wide range of body sizes and degrees of adaptation to the water, from the small Enaliornis and Pasquiaornis with lesser degrees of diving specialization to the large Hesperornis with extreme morphological specializations. Paleontologists have been studying these birds for over 150 years, dating back to the “Bone Wars” between Marsh and Cope, and as such have a long history of naming, and renaming, taxa. More recent work has focused to varying degrees on the evolutionary relationships, functional morphology, and histology of the group, but there are many opportunities remaining for better understanding these birds. Broad-scale taxonomic evaluations of the more than 20 known species, additional histological work, and the incorporation of digital visualization tools such as computed tomography scans can all add significantly to our understanding of these birds.

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Worthy, Trevor H., and David V. Burley. "Prehistoric avifaunas from the Kingdom of Tonga." Zoological Journal of the Linnean Society 189, no. 3 (November 18, 2019): 998–1045. http://dx.doi.org/10.1093/zoolinnean/zlz110.

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Abstract Avifaunas derived from Lapita archaeological sites excavated between 2004 and 2014 from four sites in the Vava'u Group and two on Tongatapu, Kingdom of Tonga are described, revealing birds encountered by the first human arrivals. A total of 741 identifiable bones revealed 24 avian taxa, among which terrestrial birds, especially rails, pigeons and parrots, were the most abundant. At a minimum, eight taxa, or 50% of the original non-passerine land bird diversity in the sample, are globally extinct. These include two megapodes (Megapodius alimentum and a larger unnamed megapode), three pigeons (a large Caloenas sp. indet., Didunculus placopedetes and Ducula shutleri sp. nov.), two rails (Hypotaenidia vavauensis sp. nov. and an unnamed one) and the parrot Eclectus infectus. The rail H. vavauensis was restricted to Vava'u and was flightless, with reduced wings, and larger than Hypotaenidia woodfordi of the Solomons, the largest congener hitherto found in the Pacific. The pigeon Du. shutleri was volant, but was the largest species in its genus and was widespread in the Kingdom. The evolution of Tongan avifaunas is related to varying ages (Pliocene to Pleistocene) of the island groups, where geological youth apparently precluded true giantism in the fauna.

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Portugal, Steven J., Craig R. White, Jonathan A. Green, and Patrick J. Butler. "Flight feather moult drives minimum daily heart rate in wild geese." Biology Letters 14, no. 11 (November 2018): 20180650. http://dx.doi.org/10.1098/rsbl.2018.0650.

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Waterfowl undergo an annual simultaneous flight-feather moult that renders them flightless for the duration of the regrowth of the flight feathers. In the wild, this period of flightlessness could restrict the capacity of moulting birds to forage and escape predation. Selection might therefore favour a short moult, but feather growth is constrained and presumably energetically demanding. We therefore tested the hypothesis that for birds that undergo a simultaneous flight-feather moult, this would be the period in the annual cycle with the highest minimum daily heart rates, reflecting these increased energetic demands. Implantable heart rate data loggers were used to record year-round heart rate in six wild barnacle geese ( Branta leucopsis ), a species that undergoes a simultaneous flight-feather moult. The mean minimum daily heart rate was calculated for each individual bird over an 11-month period, and the annual cycle was divided into seasons based on the life-history of the birds. Mean minimum daily heart rate varied significantly between seasons and was significantly elevated during wing moult, to 200 ± 32 beats min −1 , compared to all other seasons of the annual cycle, including both the spring and autumn migrations. The increase in minimum daily heart rate during moult is likely due to feather synthesis, thermoregulation and the reallocation of minerals and protein.

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FEDUCCIA, ALAN. "The scapulocoracoid of flightless birds: a primitive avian character similar to that of theropods." Ibis 128, no. 1 (April 3, 2008): 128–32. http://dx.doi.org/10.1111/j.1474-919x.1986.tb02099.x.

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KIRCHMAN, JEREMY J. "Genetic tests of rapid parallel speciation of flightless birds from an extant volant ancestor." Biological Journal of the Linnean Society 96, no. 3 (February 24, 2009): 601–16. http://dx.doi.org/10.1111/j.1095-8312.2008.01160.x.

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Serrano, Francisco J., Mireia Costa-Pérez, Guillermo Navalón, and Alberto Martín-Serra. "Morphological Disparity of the Humerus in Modern Birds." Diversity 12, no. 5 (April 28, 2020): 173. http://dx.doi.org/10.3390/d12050173.

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From a functional standpoint, the humerus is a key element in the skeleton of vertebrates as it is the forelimb’s bone that connects with the pectoral girdle. In most birds, the humerus receives both the forces exerted by the main flight muscles and the aerodynamical stresses exerted upon the wing during locomotion. Despite this functional preeminence, broad scale studies of the morphological disparity of the humerus in the crown group of birds (Neornithes) are lacking. Here, we explore the variation in shape of the humeral outline in modern birds and its evolutionary relationship with size and the evolution of different functional regimes, including several flight strategies, wing propelled diving and complete loss of wing locomotory function. Our findings suggest that most neornithines evolved repeatedly towards a general humeral morphology linked with functional advantages related with more efficient flapping. Lineages evolving high-stress locomotion such as hyperaeriality (e.g., swifts), hovering (e.g., hummingbirds) and wing-propelled diving (e.g., penguins) greatly deviate from this general trend, each exploring different morphologies. Secondarily flightless birds deviate to a lesser degree from their parent clades in humeral morphology likely as a result of the release from constraints related with wing-based locomotion. Furthermore, these taxa show a different allometric trend that flighted birds. Our results reveal that the constraints of aerial and aquatic locomotion are main factors shaping the macroevolution of humeral morphology in modern birds.

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Chen, Cheng, Sheng-bo Yu, Yan-yan Chi, Guang-yuan Tan, Bao-cheng Yan, Nan Zheng, and Hong-Jin Sui. "Existence and features of the myodural bridge in Gentoo penguins: A morphological study." PLOS ONE 16, no. 4 (April 8, 2021): e0244774. http://dx.doi.org/10.1371/journal.pone.0244774.

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Recent studies have evidenced that the anatomical structure now known as the myodural bridge (MDB) connects the suboccipital musculature to the cervical spinal dura mater (SDM). In humans, the MDB passes through both the posterior atlanto-occipital and the posterior atlanto-axial interspaces. The existence of the MDB in various mammals, including flying birds (Rock pigeons and Gallus domesticus) has been previously validated. Gentoo penguins are marine birds, able to make 450 dives per day, reaching depths of up to 660 feet. While foraging, this penguin is able to reach speeds of up to 22 miles per hour. Gentoo penguins are also the world’s fastest diving birds. The present study was therefore carried out to investigate the existence and characteristics of the MDB in Gentoo penguin (Pygoscelis papua), a non-flying, marine bird that can dive. For this study, six Gentoo penguin specimens were dissected to observe the existence and composition of their MDB. Histological staining was also performed to analyze the anatomic relationships and characteristic of the MDB in the Gentoo penguin. In this study, it was found that the suboccipital musculature in the Gentoo penguin consists of the rectus capitis dorsalis minor (RCDmi) muscle and rectus capitis dorsalis major (RCDma) muscle. Dense connective tissue fibers were observed connecting these two suboccipital muscles to the spinal dura mater (SDM). This dense connective tissue bridge consists of primarily type I collagen fibers. Thus, this penguin’s MDB appears to be analogous to the MDB previously observed in humans. The present study evidences that the MDB not only exists in penguins but it also has unique features that distinguishes it from that of flying birds. Thus, this study advances the understanding of the morphological characteristics of the MDB in flightless, marine birds.

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Collar, N. J. "The conservation status in 1982 of the Aldabra White-throated Rail Dryolimnas cuvieri aldabranus." Bird Conservation International 3, no. 4 (December 1993): 299–305. http://dx.doi.org/10.1017/s0959270900002574.

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SummaryThe Aldabra White-throated Rail Dryolimnas cuvieri aldabranus is confined to Middle Island (c. 7,700 birds), lie Polymnie (c. 270) and De aux Cèdres (c. 80) on Aldabra Atoll (now a World Heritage Site) in the Seychelles. It uses all available terrestrial habitats, but chiefly occurs in scrub cover and particularly in the densest types, where leaf-litter (and hence litter fauna) is richest. Its extinction on Assumption, Astove and Cosmoledo is attributable to widespread habitat loss and disturbance, and to human utilization as food; the extent to which rats and cats affect the form, which is flightless, is debatable.

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Marks, Jeffrey S., and Roland L. Redmond. "Conservation problems and research needs for Bristle-thighed Curlews Numenius tahitiensis on their wintering grounds." Bird Conservation International 4, no. 4 (December 1994): 329–41. http://dx.doi.org/10.1017/s0959270900002872.

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SummaryThe Bristle-thighed Curlew Numenius tahitiensis is a rare shorebird that breeds in western Alaska and winters on oceanic islands in the tropical and subtropical Pacific Ocean. Before human colonization, the islands on which curlews winter were devoid of terrestrial predators, allowing curlews to evolve a rapid moult during which about 50% of adults become flightless. Especially when flightless, these birds are vulnerable to harvest by humans and to predation by introduced mammals such as dogs and cats. On atolls where they are harvested by humans, curlews tend to occur only on uninhabited islets. Consequently, human encroachment in Oceania has probably reduced Bristle-thighed Curlew numbers and altered winter distribution of the species. Future studies should (1) identify concentrations of wintering curlews, focusing in the Tuamotu Archipelago; (2) determine whether migratory stopover sites exist in the central Pacific between Hawaii and the southern end of the wintering grounds; and (3) establish a monitoring programme to assess population trends in several parts of the winter range. A comprehensive plan is needed to provide for the existence of predator-free islands throughout key portions of the winter range.

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Buffetaut, Eric, and Delphine Angst. "Macrornis tanaupus Seeley, 1866: an enigmatic giant bird from the upper Eocene of England." Geological Magazine 158, no. 6 (February 5, 2021): 1129–34. http://dx.doi.org/10.1017/s0016756820001466.

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AbstractA large bone from the upper Eocene Totland Bay Formation of Hordle Cliff (Hampshire), originally described by Seeley (1866) as Macrornis tanaupus and interpreted by him as belonging to a ‘large Struthious bird’, is redescribed and illustrated for the first time. It is not a reptile bone, as previously suggested, but the proximal part of a left avian tibiotarsus. A mass estimate of 43 kg, comparable to that of an emu, suggests that it was flightless. A precise identification is difficult because of the incompleteness of the specimen, and Macrornis tanaupus should probably be considered as a nomen dubium. We exclude Seeley’s interpretation as a ratite, as well as previous attributions to gastornithids. We tentatively suggest that the specimen may belong to a phorusrhacid, which would extend the stratigraphic record of this group in Europe by a few million years. The presence of a large terrestrial bird in the upper Eocene of Europe may have a bearing on the interpretation of enigmatic footprints of very large birds from the upper Eocene Paris gypsum.

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Sayão, Juliana M., Antonio A. F. Saraiva, and Angelica M. K. Uejima. "New evidence of feathers in the Crato Formation supporting a reappraisal on the presence of Aves." Anais da Academia Brasileira de Ciências 83, no. 1 (March 2011): 197–210. http://dx.doi.org/10.1590/s0001-37652011000100010.

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The preservation of delicate structures such as feathers is very rare in the paleontological record, due to the fragility of their components. Fossil feathers have been reported from approximately 50 deposits around the world, from the Late Jurassic to the Pleistocene. In Brazil initial findings consisted of a primary feather of a large bird found in the Tremembé Formation. Other occurrences are preserved in the Crato Formation, where several symmetrical and one single asymmetrical feather was found. Based on three new specimens and reassessing further feather occurrences we cannot confirm the presence of volant Aves in this deposit. The presence of an asymmetrical feather without barbules and hooks hints at the previous existence of a flightless animal within this deposit, possibly a flightlessness bird or a non-avian theropod. Conversely, the presence of a feather from morphotype II present in Tyrannosauroidea, Compsognathidae, Therizinosauroidea and Dromeosauridae, points to a non-theropod origin. Since there are no confirmed records of birds and other feathered archosaurs in the region to date, more evidence is required to identify the animal from which these structures originated.

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Journal articles on the topic 'Flightless birds'

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