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We describe a partial skull of a very large crane from the early late Miocene (Tortonian) hominid locality Hammerschmiede in southern Germany, which is the oldest fossil record of the Gruinae (true cranes). The fossil exhibits an unusual preservation in that only the dorsal portions of the neurocranium and beak are preserved. Even though it is, therefore, very fragmentary, two morphological characteristics are striking and of paleobiological significance: its large size and the very long beak. The fossil is from a species the size of the largest extant cranes and represents the earliest record of a large-sized crane in Europe. Overall, the specimen resembles the skull of the extant, very long-beaked Siberian Crane, Leucogeranus leucogeranus, but its affinities within Gruinae cannot be determined owing to the incomplete preservation. Judging from its size, the fossil may possibly belong to the very large âGrusâ pentelici, which stems from temporally and geographically proximate sites. The long beak of the Hammerschmiede crane conforms to an open freshwater paleohabitat, which prevailed at the locality.
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Significance
Flapping flight is extremely costly for large birds, yet little is known about the conditions that force them to flap. We attached custom-made âflight recordersâ to Andean condors, the worldâs heaviest soaring birds, documenting every single wingbeat and when and how individuals gained altitude. Remarkably, condors flapped for only 1% of their flight time, specifically during takeoff and when close to the ground. This is particularly striking as the birds were immature. Thus, our results demonstrate that even inexperienced birds can cover vast distances over land without flapping. Overall, this can help explain how extinct birds with twice the wingspan of condors could have flown.
Abstract
Flight costs are predicted to vary with environmental conditions, and this should ultimately determine the movement capacity and distributions of large soaring birds. Despite this, little is known about how flight effort varies with environmental parameters. We deployed bio-logging devices on the worldâs heaviest soaring bird, the Andean condor (Vultur gryphus), to assess the extent to which these birds can operate without resorting to powered flight. Our records of individual wingbeats in >216 h of flight show that condors can sustain soaring across a wide range of wind and thermal conditions, flapping for only 1% of their flight time. This is among the very lowest estimated movement costs in vertebrates. One bird even flew for >5 h without flapping, covering ~172 km. Overall, > 75% of flapping flight was associated with takeoffs. Movement between weak thermal updrafts at the start of the day also imposed a metabolic cost, with birds flapping toward the end of glides to reach ephemeral thermal updrafts. Nonetheless, the investment required was still remarkably low, and even in winter conditions with weak thermals, condors are only predicted to flap for ~2 s per kilometer. Therefore, the overall flight effort in the largest soaring birds appears to be constrained by the requirements for takeoff.
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Study examines flight performance in the heaviest soaring birds
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http://www.ornis.hu/articles/OrnisHungarica_vol28(1)_p121-168.pdfCorvids are the largest songbirds in Europe. They are known in the avian fauna of Europe from the Miocene, the beginning of the Neogene, and are currently represented by 11 species. Due to their size, they occur more frequently among fossilized material than other types of songbirds, and thus have been examined to the largest extent. In the current article, we present their known evolution and their fossilized taxa in Europe and examine the osteology of extant species.
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We report here an avian bone from this important Lower Eocene site which we believe to be attributable to an early halcyornithid.
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Bram W. Langeveld (2020)
New Finds, Sites and Radiocarbon Dates of Skeletal Remains of the Great Auk Pinguinus impennis from the Netherlands.
Ardea 108(1):5-19
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https://doi.org/10.5253/arde.v108i1.a10https://bioone.org/journals/ardea/volume-108/issue-1/arde.v108i1.a10/New-Finds-Sites-and-Radiocarbon-Dates-of-Skeletal-Remains-of/10.5253/arde.v108i1.a10.fullThe Great Auk Pinguinus impennis was a large, flightless alcid, endemic to the North Atlantic Ocean. It became extinct around 1844. Skeletal remains are used to document its (pre-)historic range. While these remains were considered rare from the southern North Sea, over the past five years 91 (sub-)fossil specimens have been recovered by citizen scientist fossil collectors from Dutch beaches that were nourished with sediments dredged from the bottom of the North Sea. Some of this material is now stored in museum collections. This paper lists the new remains and documents them through measurements and photographs. The material was recovered from fourteen new localities and one previously known locality in The Netherlands and has yielded four radiocarbon dates (1425â1300 BC till beyond 48,000 cal BP) which significantly increase the Great Auk's temporal range in this area. The sheer volume of remains alters our image of the Great Auk in the southern part of the North Sea from a rare bird to most likely a common or regular wintering bird over the past millennia.
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Climate variability is one of the most important forces affecting the distributional range dynamics of species and consequentially plays a significant role in shaping biogeographic patterns. This study aims to infer the role of climate in the recent evolutionary history of the Common Grackle Quiscalus quiscula. Studies of other migratory North American birds have shown that their populations were isolated in two or three refugia in southern North America during the Last Glacial Maximum (LGM). In contrast, preliminary genetic work suggests that Common Grackles may have occupied a single refugium during that time. They subsequently became widespread and northern populations evolved highly migratory behaviour. We used an ecological niche modelling approach that involved the use of three general climate models for the past (the LGM, approximately 22,000 years before present) and for present environmental conditions to identify climatically stable areas. Extrapolations to the past showed contraction to a large continuous refugium located in the southern part of North America, and projection to the present showed expansion that covers much of eastern and middle North America. The most important bioclimatic variable for model predictions was annual mean temperature, which explained 74% of the variation in the model. Results suggest that the Common Grackle has expanded its distributional range by more than 300% after the LGM.
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The Oxford Dodo (Raphus cucullatus) has been in the collections of the University of Oxford since 1683, first in the Ashmolean Museum and latterly in Oxford University Museum of Natural History. Prior to this the specimen was part of the collections of the Tradescants, father and son, and likely acquired between 1634 and 1656, in the MusÃum Tradescantianum in what is now Vauxhall, south London. It has been thought probable that this specimen was once the live bird recorded in London by Sir Hamon LâEstrange in around 1638, but X-ray CT scanning of the skull for anatomical investigation has cast doubt on the provenance of the Oxford Dodo. The 3D visualisation revealed 115 metal particles embedded within the bone of the skull, concentrated in the left side of the skull. All but five of the particles are less than 1 mm in diameter and their location leads to the conclusion that they represent lead shot consistent with the bird being shot from the rear right of the head, perhaps with a ventral component. This forensic discovery leaves the provenance of the Oxford specimen uncertain but illustrates the value of non-invasive visualisation techniques in determining the potentially complex histories of unique museum objects.
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The region from New Guinea through Oceania sustains the worldâs most diverse set of columbids. We describe osteological characters of the hindlimb (femur, tibiotarsus, tarsometatarsus) that divide the Papuan-Oceanic pigeons and doves into three groups based on functional morphology: "arboreal" (Hemiphaga, Ducula, Ptilinopus, Drepanoptila, Gymnophaps), âintermediateâ (Columba, Macropygia, Reinwardtoena), and "terrestrial" (Gallicolumba [includes Alopecoenas], Trugon, Microgoura, Goura, Chalcophaps, Geopelia, Henicophaps, Caloenas, Didunculus, Otidiphaps). The arboreal and terrestrial groups are each distinctive osteologically, especially in the tibiotarsus and tarsometatarsus, which are short relative to the femur in the arboreal group, and long relative to the femur in the terrestrial group. The intermediate pigeons are more similar to arboreal than to terrestrial pigeons, but nonetheless fit in neither group. To estimate the phylogenetic relationships among or within these three groups is somewhat tentative using hindlimb osteology alone, although all five genera of arboreal pigeons have independent molecular evidence of relatedness, as do most of the genera of terrestrial pigeons.
Using the hindlimb and other osteological data as a framework, we describe a new extinct genus and species of pigeon, Tongoenas burleyi, from Holocene archaeological and Pleistocene paleontological sites on six islands (Foa, Lifuka, `Uiha, Ha`afeva, Tongatapu, and `Eua) in the Kingdom of Tonga. Tongoenas was a large-sized member of the "arboreal" pigeon group, with osteological characters that relate it to Ducula, Gymnophaps, and Hemiphaga (generally canopy frugivores) rather than with the âterrestrialâ pigeons (more ground-dwelling and granivorous) such as Gallicolumba, Trugon, Microgoura, Goura, etc. (others listed above). Among volant columbids, living or extinct, only the species of Goura (from New Guinea) are larger than Tongoenas. From most of the same prehistoric sites, we also report new material of the nearly as large, extinct pigeon Ducula shutleri Worthy & Burley, recently described from islands in the Vava`u Group of Tonga. Thus, D. shutleri also was widespread in Tonga before human impact. The prehistoric anthropogenic loss in Tonga of Tongoenas burleyi, Ducula shutleri, and other columbids undoubtedly had a negative impact on the dispersal regimes of Tongan forest trees. At first human contact about 2850 years ago, at least nine species of columbids in six genera inhabited the Tongan islands, where only four species in three genera exist today.
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R.N. Holdaway & R.J. Rowe (2020)
Palaeoecological reconstructions depend on accurate species identification: examples from South Island, New Zealand, Pachyornis (Aves: Dinornithiformes).
Notornis 67(2): 494-502
https://www.notornis.osnz.org.nz/node/4499
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