Results 1 to 10 of about 44,474 (174)

Flight feather development: its early specialization during embryogenesis. [PDF]

Zoological Lett, 2018
Flight feathers, a type of feather that is unique to extant/extinct birds and some non-avian dinosaurs, are the most evolutionally advanced type of feather. In general, feather types are formed in the second or later generation of feathers at the first and following molting, and the first molting begins at around two weeks post hatching in chicken ...
Kondo M, Sekine T, Miyakoshi T, Kitajima K, Egawa S, Seki R, Abe G, Tamura K.   +7 more
europepmc   +6 more sources

The Making of a Flight Feather: Bio-architectural Principles and Adaptation. [PDF]

Cell, 2019
The evolution of flight in feathered dinosaurs and early birds over millions of years required flight feathers whose architecture features hierarchical branches. While barb-based feather forms were investigated, feather shafts and vanes are understudied.
Chang WL, Wu H, Chiu YK, Wang S, Jiang TX, Luo ZL, Lin YC, Li A, Hsu JT, Huang HL, Gu HJ, Lin TY, Yang SM, Lee TT, Lai YC, Lei M, Shie MY, Yao CT, Chen YW, Tsai JC, Shieh SJ, Hwu YK, Cheng HC, Tang PC, Hung SC, Chen CF, Habib M, Widelitz RB, Wu P, Juan WT, Chuong CM.   +30 more
europepmc   +6 more sources

The flight feather moult pattern of the bearded vulture (Gypaetus barbatus) [PDF]

Journal of Ornithology, 2015
Moult is an extremely time-consuming and energy-demanding task for large birds. In addition, there is a trade-off between the time devoted to moulting and that invested in other activities such as breeding and/or territory exploration. Moreover, it takes
Íñigo Zuberogoitia, Juan Antonio Gil, José E. Martínez, Birgit Erni, Bakartxo Aniz, Pascual López‐López   +5 more
core   +5 more sources

Untangling causes of variation in mercury concentration between flight feathers [PDF]

Environmental Pollution, 2020
Bird feathers are one of the most widely used animal tissue in mercury biomonitoring, owing to the ease of collection and storage. They are also the principal excretory pathway of mercury in birds. However, limitations in our understanding of the physiology of mercury deposition in feathers has placed doubt on the interpretation of feather mercury ...
Marie Claire Gatt, Ricardo Furtado, José P. Granadeiro, Daniel Lopes, Eduarda Pereira, Paulo Catry   +5 more
openalex   +5 more sources

Sonic hedgehog specifies flight feather positional information in avian wings. [PDF]

Development, 2020
ABSTRACT Classical tissue recombination experiments performed in the chick embryo provide evidence that signals operating during early limb development specify the position and identity of feathers. Here, we show that Sonic hedgehog (Shh) signalling in the embryonic chick wing bud specifies positional information required for the ...
Busby L, Aceituno C, McQueen C, Rich CA, Ros MA, Towers M.   +5 more
europepmc   +7 more sources

Relative mass of flight feathers in waders – an update

Wader Study, 2018
Studies of moult of flight feathers have traditionally used the moult score, in which primaries were scored between 0 (old) and 5 (fully grown new primary) and added up. The moult score eventually became increasingly replaced by the percentage of grown feather mass because each flight feather has a different mass which should be corrected for. Although
Włodzimierz Meissner, Grzegorz Zaniewicz, Patrycja Gogg, Lucyna Pilacka, Marcel Klaassen, Clive Minton   +5 more
openalex   +3 more sources

Flight feather moult drives minimum daily heart rate in wild geese. [PDF]

Biol Lett, 2018
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
Portugal SJ, White CR, Green JA, Butler PJ.   +3 more
europepmc   +4 more sources

Mechanics Of Flight Feathers: Effects Of Captivity? [PDF]

, 2020
ABSTRACTFeathers act as aerodynamic cantilevers, and to withstand the prolonged cyclical loading that occurs during flight, feathers must be stiff, lightweight and strong. We experimentally tested the differences in feather structure, primarily stiffness and size, between (a) wild and captive Barnacle GeeseBranta leucopsis,and (b) primary feathers ...
Steven J. Portugal, Robert L. Nudds, Jonathan A. Green, Rhea Alexander, P. J. Butler, R. F. Ker   +5 more
openalex   +2 more sources

Allometry of the duration of flight feather molt in birds. [PDF]

PLoS Biol, 2009
We used allometric scaling to explain why the regular replacement of the primary flight feathers requires disproportionately more time for large birds. Primary growth rate scales to mass (M) as M(0.171), whereas the summed length of the primaries scales almost twice as fast (M(0.316)).
Rohwer S, Ricklefs RE, Rohwer VG, Copple MM.   +3 more
europepmc   +5 more sources

Distributed feather-inspired flow control mitigates stall and expands flight envelope

Proceedings of the National Academy of Sciences
Multiple rows of feathers, known as the covert feathers, contour the upper and lower surfaces of bird wings. These feathers have been observed to deploy passively during high angle of attack maneuvers and are suggested to play an aerodynamic role. However, there have been limited attempts to capture their underlying flow physics or assess the function ...
Girguis Sedky, Nathaniel Simon, Ahmed K. Othman, H. Wiswell, Aimy Wissa   +4 more
openalex   +3 more sources