Contributions of feather microstructure to eider down insulation properties

2017 ◽  
Vol 48 (8) ◽  
pp. 1150-1157 ◽  
Author(s):  
Liliana D'alba ◽  
Thomas Holm Carlsen ◽  
Árni Ásgeirsson ◽  
Matthew D. Shawkey ◽  
Jón Einar Jónsson
The Auk ◽  
2018 ◽  
Vol 135 (3) ◽  
pp. 777-787 ◽  
Author(s):  
Felicia B. Kulp ◽  
Liliana D'Alba ◽  
Matthew D. Shawkey ◽  
Julia A. Clarke

2019 ◽  
Vol 128 (3) ◽  
pp. 550-568 ◽  
Author(s):  
Marie Fan ◽  
Liliana D’alba ◽  
Matthew D Shawkey ◽  
Anne Peters ◽  
Kaspar Delhey

AbstractClosely related species often differ in coloration. Understanding the mechanistic bases of such differences can reveal whether evolutionary changes in colour are driven by single key mechanisms or changes in multiple pathways. Non-iridescent structural plumage colours in birds are a good model in which to test these questions. These colours result from light absorption by pigments, light scattering by the medullary spongy layer (a nanostructure found within barbs) and contributions from other structural elements. Fairy-wrens (Malurus spp.) are a small clade of closely related birds that display a large diversity of ornamental structural colours. Using spectrometry, electron microscopy and Fourier analysis, we show that 30 structural colours, varying from ultraviolet to blue and purple, share a similar barb morphology. Despite this similarity, we find that at the microscopic scale, variation across multiple structural elements, including the size and density of the keratin cortex, spongy layer and melanin, explains colour diversity. These independent axes of morphological variation together account for sizeable amounts of structural colour variability (R2 = 0.21–0.65). The coexistence of many independent, evolutionarily labile mechanisms that generate colour variation suggests that the diversity of structural colours in this clade could be mediated by many independent genetic and environmental factors.


2021 ◽  
Vol 9 (1) ◽  
pp. 51-64
Author(s):  
Swapna Devi Ray ◽  
◽  
Prateek Dey ◽  
Nozrul Islam ◽  
Sanjeev Kumar Sharma ◽  
...  

Though a few in numbers, investigations on feather microstructures from the early 20th century till date, have contributed immensely to various fields such as phylogeny, palaeontology, archaeology, wildlife forensic, biomechanics and so on. However, existing studies on feather micro-structures of birds endemic to the India/Indian sub-continent are few in number and limited in their scope. Also, no study has ever been conducted to compare feather microstructures of different individuals of a species from India. To address this issue, a comparative feather microstructure study of three individuals of Turdoides affinis, a passerine endemic to the Indian sub-continent was done. Select microstructure parameters for five different types of feathers were studied in detail. The molecular sexing method was used to elucidate the sex of T. affinis individuals for gender based differences if any. Results of the study identified that two of T. affinis individuals were female whereas one of them was male. Morphometrically, tail contour was the longest (9.63±0.76 cm) and bristle were the shortest (1.00±0.07 cm) feather. Semiplume had the longest barb length (1.73±0.04 cm) and shortest barbs (0.16±0.01 cm) were present in bristles. Subpennaceous barbs and knob-shaped villi, characteristic of members of the Passeriformes family, was also observed in all three individuals. This study records no significant difference in feather characteristics amongst the three T. affinis individuals irrespective of the differences in their sex and size. Systematically documented feather micro-characteristics of T. affinis in this study could be used as a species identification tool and would provide baseline data for the feather catalogue of Indian bird species being compiled at SACON.


2002 ◽  
Vol 143 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fu-Min Lei ◽  
Yan-Hua Qu ◽  
Ya-Ling Gan ◽  
Axel Gebauer ◽  
Martin Kaiser

MRS Bulletin ◽  
2014 ◽  
Vol 39 (7) ◽  
pp. 572-572
Author(s):  
Mary Nora Dickson

2011 ◽  
Vol 38 (4) ◽  
pp. 369-378 ◽  
Author(s):  
E. O. Fadeeva ◽  
O. F. Chernova

2002 ◽  
Vol 143 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fu-Min Lei ◽  
Yan-Hua Qu ◽  
Ya-Ling Gan ◽  
Axel Gebauer ◽  
Martin Kaiser

2014 ◽  
Vol 496 ◽  
pp. 257-263 ◽  
Author(s):  
Lora A. Morandin ◽  
Patrick D. O'Hara

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