Titre: Echolocation. The cost of being a bat Auteur:Rayner, J M Sujet:Echolocation ; Chiroptera -- Physiology Fait partie de:
Nature, 04 April 1991, Vol.350(6317), pp.383-4
Identifiant:
0028-0836 (ISSN); 2011188 Version (PMID)
Rayner, J M
The Journal of experimental biology, December 1999, Vol.202(Pt 23), pp.3449-61
[Revue évaluée par les pairs]
MEDLINE/PubMed (U.S. National Library of Medicine)
Titre: Estimating power curves of flying vertebrates Auteur:Rayner, J M Sujet:Flight, Animal -- Physiology ; Vertebrates -- Physiology Description:
The power required for flight in any flying animal is a function of flight speed. The power curve that describes this function has become an icon of studies of flight mechanics and physiology because it encapsulates the accessible animal's flight performance. The mechanical or aerodynamic power curve, describing the increase in kinetic energy of the air due to the passage of the bird, is necessarily U-shaped, for aerodynamic reasons, and can be estimated adequately by lifting-line theory. Predictions from this and related models agree well with measured mechanical work in flight and with results from flow visualization experiments. The total or metabolic power curve also includes energy released by the animal as heat, and is more variable in shape. These curves may be J-shaped for smaller birds and bats, but are difficult to predict theoretically owing to uncertainty about internal physiological processes and the efficiency of the flight muscles. The limitations of some existing models...
Fait partie de:
The Journal of experimental biology, December 1999, Vol.202(Pt 23), pp.3449-61
Identifiant:
0022-0949 (ISSN); 10562528 Version (PMID)
Plusieurs versions
The Avian Tail Reduces Body Parasite Drag by Controlling Flow Separation and Vortex Shedding
Maybury, W. J., Rayner, J. M. V.
Proceedings: Biological Sciences, 07 July 2001, Vol.268(1474), pp.1405-1410
[Revue évaluée par les pairs]
Nudds, R. L., Rayner, J. M. V.
Proceedings: Biological Sciences, 07 August 2004, Vol.271, pp.S324-S327
[Revue évaluée par les pairs]
Archival Journals (JSTOR)
Titre: Forelimb Proportions and the Evolutionary Radiation of Neornithes Auteur:Nudds, R. L.; Rayner, J. M. V. Description:
Analysis of a comprehensive dataset demonstrates that the brachial index (BI = humerus length/ulna length) of modern birds (Neornithes) varies significantly between clades at all taxonomic levels, yet is strongly correlated with recent phylogenetic hypotheses. Variance in BI at the infraclass level is low, but increases rapidly during the proposed major radiation of neornithines in the Palaeocene and Eocene. Although a BI of greater than 1 is primitive for Neornithes, more basal groups of Mesozoic birds (Confuciusornithidae and some members of the diverse Enantiornithidae) had BIs comparable with those of 'higher' modern clades. It is possible that occupation of ecological niches by these Mesozoic clades precluded the divergence of some groups of neornithines until after the Cretaceous-Tertiary boundary. We suggest that with further analysis and data collection the relationships between flight behaviour, ecology and BI can be determined. Hence, BI may provide a useful tool for characterizing the ecology of fossil birds.
Fait partie de:
Proceedings: Biological Sciences, 07 August 2004, Vol.271, pp.S324-S327
Identifiant:
09628452 (ISSN)
Maybury, W J, Rayner, J M, Couldrick, L B
Proceedings. Biological sciences, 22 July 2001, Vol.268(1475), pp.1443-8
[Revue évaluée par les pairs]
MEDLINE/PubMed (U.S. National Library of Medicine)
Titre: Lift generation by the avian tail Auteur:Maybury, W J; Rayner, J M; Couldrick, L B Sujet:Flight, Animal -- Physiology ; Songbirds -- Physiology ; Tail -- Physiology Description:
Variation with tail spread of the lift generated by a bird tail was measured on mounted, frozen European starlings (Sturnus vulgaris) in a wind tunnel at a typical air speed and body and tail angle of attack in order to test predictions of existing aerodynamic theories modelling tail lift. Measured lift at all but the lowest tail spread angles was significantly lower than the predictions of slender wing, leading edge vortex and lifting line models of lift production. Instead, the tail lift coefficient based on tail area was independent of tail spread, tail aspect ratio and maximum tail span. Theoretical models do not predict bird tail lift reliably and, when applied to tail morphology, may underestimate the aerodynamic optimum tail feather length. Flow visualization experiments reveal that an isolated tail generates leading edge vortices as expected for a low-aspect ratio delta wing, but that in the intact bird body-tail interactions are critical in determining tail aerodynamics: lifting vortices shed from the body interact with the tail and degrade tail lift compared with that of an isolated tail.
Fait partie de:
Proceedings. Biological sciences, 22 July 2001, Vol.268(1475), pp.1443-8
Identifiant:
0962-8452 (ISSN); 11454286 Version (PMID)
Nudds, R L, Dyke, G J, Rayner, J M V
Proceedings. Biological sciences, 07 August 2004, Vol.271 Suppl 5, pp.S324-7
[Revue évaluée par les pairs]
MEDLINE/PubMed (U.S. National Library of Medicine)
Titre: Forelimb proportions and the evolutionary radiation of Neornithes Auteur:Nudds, R L; Dyke, G J; Rayner, J M V Sujet:Fossils ; Phylogeny ; Birds -- Anatomy & Histology ; Wings, Animal -- Anatomy & Histology Description:
Analysis of a comprehensive dataset demonstrates that the brachial index (BI = humerus length/ulna length) of modern birds (Neornithes) varies significantly between clades at all taxonomic levels, yet is strongly correlated with recent phylogenetic hypotheses. Variance in BI at the infraclass level is low, but increases rapidly during the proposed major radiation of neornithines in the Palaeocene and Eocene. Although a BI of greater than 1 is primitive for Neornithes, more basal groups of Mesozoic birds (Confuciusornithidae and some members of the diverse Enantiornithidae) had BIs comparable with those of 'higher' modern clades. It is possible that occupation of ecological niches by these Mesozoic clades precluded the divergence of some groups of neornithines until after the Cretaceous-Tertiary boundary. We suggest that with further analysis and data collection the relationships between flight behaviour, ecology and BI can be determined. Hence, BI may provide a useful tool for characterizing...
Fait partie de:
Proceedings. Biological sciences, 07 August 2004, Vol.271 Suppl 5, pp.S324-7
Identifiant:
0962-8452 (ISSN); 15504007 Version (PMID)
Maybury, W. J., Rayner, J. M. V., Couldrick, L. B.
Proceedings: Biological Sciences, 22 July 2001, Vol.268(1475), pp.1443-1448
[Revue évaluée par les pairs]
Archival Journals (JSTOR)
Titre: Lift Generation by the Avian Tail Auteur:Maybury, W. J.; Rayner, J. M. V.; Couldrick, L. B. Description:
Variation with tail spread of the lift generated by a bird tail was measured on mounted, frozen European starlings (Sturnus vulgaris) in a wind tunnel at a typical air speed and body and tail angle of attack in order to test predictions of existing aerodynamic theories modelling tail lift. Measured lift at all but the lowest tail spread angles was significantly lower than the predictions of slender wing, leading edge vortex and lifting line models of lift production. Instead, the tail lift coefficient based on tail area was independent of tail spread, tail aspect ratio and maximum tail span. Theoretical models do not predict bird tail lift reliably and, when applied to tail morphology, may underestimate the aerodynamic optimum tail feather length. Flow visualization experiments reveal that an isolated tail generates leading edge vortices as expected for a low-aspect ratio delta wing, but that in the intact bird body-tail interactions are critical in determining tail aerodynamics: lifting vortices shed from the body interact with the tail and degrade tail lift compared with that of an isolated tail.
Fait partie de:
Proceedings: Biological Sciences, 22 July 2001, Vol.268(1475), pp.1443-1448
Identifiant:
09628452 (ISSN)