The Effect of Simulated Flight Feather Moult on Escape Take-Off Performance in Starlings

Flying bird has gradually formed airworthy structures e.g. streamlined shape and hollow shaft of feather to improve flying performance by millions of years natural selection. As typical property of flight feather, herringbone-type riblets can be observed along the shaft of each feather, which caused by perfect alignment of barbs. Why bird feather have such herringbone-type riblets has not been extensively discussed until now. In this paper, microstructures of secondary feathers are investigated through SEM photo of various birds involving adult pigeons, wild goose and magpie. Their structural parameters of herringbone riblets of secondary flight feather are statistically obtained. Based on quantitative analysis of feathers structure, one novel biomimetic herringbone riblets with narrow smooth edge are proposed to reduce surface drag. In comparison with traditional microgroove riblets and other drag reduction structures, the drag reduction rate of the proposed biomimetic herringbone riblets is experimentally clarified up to 15%, much higher than others. Moreover, the drag reduction mechanism of herringbone riblets are also confirmed and exploited by CFD.

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In vivo strains in pigeon flight feather shafts: implications for structural design

Journal of Experimental Biology ◽

10.1242/jeb.201.22.3057 ◽

1998 ◽

Vol 201 (22) ◽

pp. 3057-3065 ◽

Cited By ~ 8

Author(s):

WR Corning ◽

AA Biewener

Keyword(s):

Safety Factor ◽

Tensile Strain ◽

Columba Livia ◽

Failure Stress ◽

Metal Foil ◽

Bending Tests ◽

Flight Feather ◽

Four Point Bending ◽

The Mean

To evaluate the safety factor for flight feather shafts, in vivo strains were recorded during free flight from the dorsal surface of a variety of flight feathers of captive pigeons (Columba livia) using metal foil strain gauges. Strains recorded while the birds flew at a slow speed (approximately 5-6 m s-1) were used to calculate functional stresses on the basis of published values for the elastic modulus of feather keratin. These stresses were then compared with measurements of the failure stress obtained from four-point bending tests of whole sections of the rachis at a similar location. Recorded strains followed an oscillatory pattern, changing from tensile strain during the upstroke to compressive strain during the downstroke. Peak compressive strains were 2.2+/-0. 9 times (mean +/- s.d.) greater than peak tensile strains. Tensile strain peaks were generally not as large in more proximal flight feathers. Maximal compressive strains averaged -0.0033+/-0.0012 and occurred late in the downstroke. Bending tests demonstrated that feather shafts are most likely to fail through local buckling of their compact keratin cortex. A comparison of the mean (8.3 MPa) and maximum (15.7 MPa) peak stresses calculated from the in vivo strain recordings with the mean failure stress measured in four-point bending (137 MPa) yields a safety factor of between 9 and 17. Under more strenuous flight conditions, feather stresses are estimated to be 1.4-fold higher, reducing their safety factor to the range 6-12. These values seem high, considering that the safety factor of the humerus of pigeons has been estimated to be between 1.9 and 3.5. Several hypotheses explaining this difference in safety factor are considered, but the most reasonable explanation appears to be that flexural stiffness is more critical than strength to feather shaft performance.

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Viscoelastic Characterization of Long-Eared Owl Flight Feather Shaft and the Damping Ability Analysis

Shock and Vibration ◽

10.1155/2014/709367 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9

Author(s):

Jia-li Gao ◽

Jin-kui Chu ◽

Le Guan ◽

Hai-xin Shang ◽

Zhen-kun Lei

Keyword(s):

Tensile Tests ◽

Uniaxial Tensile ◽

Golden Eagle ◽

Flight Feather ◽

Column Material ◽

Significant Difference ◽

Single Column ◽

Linear Viscoelastic ◽

Standard Linear Solid ◽

Standard Linear

Flight feather shaft of long-eared owl is characterized by a three-parameter model for linear viscoelastic solids to reveal its damping ability. Uniaxial tensile tests of the long-eared owl, pigeon, and golden eagle flight feather shaft specimens were carried out based on Instron 3345 single column material testing system, respectively, and viscoelastic response of their stress and strain was described by the standard linear solid model. Parameter fitting result obtained from the tensile tests shows that there is no significant difference in instantaneous elastic modulus for the three birds’ feather shafts, but the owl shaft has the highest viscosity, implying more obvious viscoelastic performance. Dynamic mechanical property was characterized based on the tensile testing results. Loss factor (tanδ) of the owl flight feather shaft was calculated to be 1.609 ± 0.238, far greater than those of the pigeon (0.896 ± 0.082) and golden eagle (1.087 ± 0.074). It is concluded that the long-eared owl flight feather has more outstanding damping ability compared to the pigeon and golden eagle flight feather shaft. Consequently, the long-eared owl flight feathers can dissipate the vibration energy more effectively during the flying process based on the principle of damping mechanism, for the purpose of vibration attenuation and structure radiated noise reduction.

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Life History Implications of Complete and Incomplete Primary Molts in Pelagic Cormorants

The Condor ◽

10.1093/condor/103.3.555 ◽

2001 ◽

Vol 103 (3) ◽

pp. 555-569 ◽

Cited By ~ 1

Author(s):

Christopher E. Filardi ◽

Sievert Rohwer

Keyword(s):

Life History ◽

North America ◽

North American ◽

Northeastern Asia ◽

Flight Feather ◽

Historia De Vida

Abstract We describe the rules of primary flight-feather replacement for Pelagic Cormorants (Phalacrocorax pelagicus), and contrast the completeness of primary replacement in individuals from Asia and North America. In adult Pelagic Cormorants primary replacement is stepwise, with multiple waves of molt, each initiated at the innermost primary (P1), proceeding simultaneously toward the tip of the wing. Shugart and Rohwer's (1996) ontogenetic model for generating and maintaining stepwise primary replacement depended upon incomplete molts. In each new episode of molt, waves of primary replacement were thought to be initiated at P1 and at each arrested wave that had failed to replace all old feathers in the preceding molt. Because most adult Pelagic Cormorants from North America completely replace their primaries but maintain stepwise primary molts, the latter assumption must be relaxed. In contrast to the present-day situation in North America, Pelagic Cormorants from northeastern Asia have incomplete molts of their primaries, and may be forced to skip breeding in some years to clear their wings of overworn primaries. Young birds from Asia start the replacement of their juvenile primaries later than North American birds and replace more feathers simultaneously. Implicancias de la Muda Primaria Completa e Incompleta en la Historia de Vida de Phalacrocorax pelagicus Resumen. Describimos las reglas de reemplazo de plumas primarias para Phalacrocorax pelagicus y contrastamos la totalización del reemplazo de primarias entre individuos de Asia y América del Norte. En individuos adultos, el reemplazo de primarias ocurre en varias etapas, con múltiples secuencias de muda cada una iniciada en la primaria más interna (P1), procediendo simultáneamente hacia la punta del ala. El modelo ontogenético de Shugart y Rohwer (1996) para la generación y mantenimiento del reemplazo en etapas de las plumas primarias depende de mudas incompletas. Se pensaba que en cada nuevo episodio de muda las secuencias de reemplazo de primarias eran iniciadas en P1 y en cada punto de interrupción de la muda precedente que hubiera impedido el reemplazo de todas las plumas viejas. Debido a que la mayoría de los individuos adultos de P. pelagicus de Norteamérica reeemplazan completamente sus primarias pero aún lo hacen en etapas, la última suposición debe ser re-evaluada. En contraste con la situación actual en Norteamérica, individuos del noreste de Asia tienen mudas incompletas de sus primarias y pueden verse forzados a no reproducirse en algunos años para despojarse de la presencia de primarias desgastadas. Las aves juveniles de Asia comienzan el reemplazo de sus primarias más tarde y reemplazan más plumas simultáneamente que las aves de Norteamérica.

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Selection of tawny owl (Strix aluco) flight feather shaft for biomonitoring As, Cd and Pb pollution

Environmental Science and Pollution Research ◽

10.1007/s11356-018-1477-5 ◽

2018 ◽

Vol 25 (14) ◽

pp. 14271-14276 ◽

Cited By ~ 2

Author(s):

Rita García Seoane ◽

Zulema Varela Río ◽

Alejo Carballeira Ocaña ◽

José Ángel Fernández Escribano ◽

Jesús Ramón Aboal Viñas

Keyword(s):

Tawny Owl ◽

Flight Feather ◽

Strix Aluco ◽

Pb Pollution ◽

Selection Of

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Measuring the flexibility matrix of an eagle’s flight feather and a method to estimate the stiffness distribution

Chinese Physics B ◽

10.1088/1674-1056/28/7/074703 ◽

2019 ◽

Vol 28 (7) ◽

pp. 074703

Author(s):

Di Tang ◽

Hai Zhu ◽

Wei Yuan ◽

Zhongyong Fan ◽

Mingxia Lei

Keyword(s):

Flight Feather ◽

Flexibility Matrix ◽

Stiffness Distribution

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POLYMORPHIC FLIGHT-FEATHER MOLT SEQUENCE IN TUFTED PUFFINS (FRATERCULA CIRRHATA): A RARE PHENOMENON IN BIRDS

The Auk ◽

10.1642/0004-8038(2004)121[0035:pfmsit]2.0.co;2 ◽

2004 ◽

Vol 121 (1) ◽

pp. 35 ◽

Cited By ~ 7

Author(s):

Christopher W. Thompson ◽

Alexander S. Kitaysky

Keyword(s):

Flight Feather ◽

Rare Phenomenon ◽

Feather Molt

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High-intensity flight feather molt and comparative molt ecology of warblers of eastern North America

The Auk ◽

10.1093/ornithology/ukaa072 ◽

2021 ◽

Vol 138 (1) ◽

Author(s):

Ronald L Mumme ◽

Robert S Mulvihill ◽

David Norman

Keyword(s):

North America ◽

Parental Care ◽

High Intensity ◽

Bird Species ◽

Late Summer ◽

Positive Association ◽

Eastern North America ◽

Surprising Result ◽

Flight Feather ◽

Feather Molt

Abstract Rapid high-intensity molt of flight feathers occurs in many bird species and can have several detrimental consequences, including reductions in flight capabilities, foraging performance, parental care, and plumage quality. Many migratory New World warblers (family Parulidae) are known to have intense remigial molt, and recent work has suggested that simultaneous replacement of the rectrices may be widespread in the family as well. However, the phylogenetic distribution of simultaneous rectrix molt, and high-intensity flight feather molt more generally, has not been systematically investigated in warblers. We addressed this issue by examining flight feather molt in 13 species, representing 7 different warbler genera, at Powdermill Avian Research Center in southwestern Pennsylvania, USA. All 13 species replaced their 12 rectrices simultaneously, with the onset of rectrix molt occurring in the early-middle stages of high-intensity primary molt. As expected, single-brooded early migrants molted earlier than double-brooded species whose nesting activities extend into late summer. However, our finding that late-molting species replaced their primaries more slowly and less intensively than early molting species was unexpected, as late-molting species are widely hypothesized to be under stronger migration-related time constraints. This surprising result appears to be at least partially explained by a positive association between the pace of molt and daylength; shorter late-summer days may mandate reduced daily food intake, lower molt intensity, and a slower pace of molt. In comparison to other passerines, flight feather molt in warblers of eastern North America is extraordinarily intense; at its peak, individuals are simultaneously replacing 50–67% of their 48 flight feathers (all 12 rectrices and 6–10 remiges on each wing) for 2–3 weeks or more. Because molt of this intensity is likely to present numerous challenges for flight, avoiding predators, foraging, and parental care, the period of flight feather molt for warblers constitutes a highly demanding phase of their annual cycle.

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