Correlation of the mechanical and structural properties of cortical rachis keratin of rectrices of the Toco Toucan (Ramphastos toco). 2011

S G Bodde, and M A Meyers, and J McKittrick
Materials Science and Engineering Program, Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093-0418, United States.

Mechanical characterization of the cortex of rectrices (tail feathers) of the Toco Toucan (Ramphastos toco) has been carried out by tensile testing of the rachis cortex in order to systematically determine Young's modulus and maximum tensile strength gradients on the surfaces and along the length of the feather. Of over seventy-five samples tested, the average Young's modulus was found to be 2.56±0.09 GPa, and maximum tensile strength was found to be 78±6 MPa. The Weibull modulus for all sets is greater than one and less than four, indicating that measured strength is highly variable. The highest Weibull moduli were reported for dorsal samplings. Dorsal and ventral surfaces of the cortex are both significantly stiffer and stronger than lateral rachis cortex. On the dorsal surface, cortex sampled from the distal end of the feather was found to be least stiff and weakest compared to that sampled from proximal and middle regions along the length of the feather. Distinctive fracture patterns correspond to failure in the superficial cuticle layer and the bulk of the rachis cortex. In the cuticle, where supramolecular keratinous fibers are oriented tangentially, evidence of ductile tearing was observed. In the bulk cortex, where the fibers are bundled and oriented longitudinally, patterns suggestive of near-periodic aggregation and brittle failure were observed.

UI MeSH Term Description Entries
D007633 Keratins A class of fibrous proteins or scleroproteins that represents the principal constituent of EPIDERMIS; HAIR; NAILS; horny tissues, and the organic matrix of tooth ENAMEL. Two major conformational groups have been characterized, alpha-keratin, whose peptide backbone forms a coiled-coil alpha helical structure consisting of TYPE I KERATIN and a TYPE II KERATIN, and beta-keratin, whose backbone forms a zigzag or pleated sheet structure. alpha-Keratins have been classified into at least 20 subtypes. In addition multiple isoforms of subtypes have been found which may be due to GENE DUPLICATION. Cytokeratin,Keratin Associated Protein,Keratin,Keratin-Associated Proteins,alpha-Keratin,Associated Protein, Keratin,Keratin Associated Proteins,Protein, Keratin Associated,alpha Keratin
D008124 Locomotion Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms. Locomotor Activity,Activities, Locomotor,Activity, Locomotor,Locomotor Activities
D008297 Male Males
D005241 Feathers Flat keratinous structures found on the skin surface of birds. Feathers are made partly of a hollow shaft fringed with barbs. They constitute the plumage. Feather
D005260 Female Females
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001717 Birds Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves. Aves,Bird
D013314 Stress, Mechanical A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area. Mechanical Stress,Mechanical Stresses,Stresses, Mechanical
D013623 Tail An extension of the posterior of an animal body beyond the TORSO. Tails
D013718 Tensile Strength The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001) Strength, Tensile,Strengths, Tensile,Tensile Strengths

Related Publications

S G Bodde, and M A Meyers, and J McKittrick
December 2016, Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians,
S G Bodde, and M A Meyers, and J McKittrick
September 2020, Brazilian journal of biology = Revista brasleira de biologia,
S G Bodde, and M A Meyers, and J McKittrick
September 2016, Journal of avian medicine and surgery,
S G Bodde, and M A Meyers, and J McKittrick
February 2006, Brazilian journal of biology = Revista brasleira de biologia,
S G Bodde, and M A Meyers, and J McKittrick
November 2021, Anatomia, histologia, embryologia,
S G Bodde, and M A Meyers, and J McKittrick
March 2003, Revista de biologia tropical,
S G Bodde, and M A Meyers, and J McKittrick
July 2020, Anatomia, histologia, embryologia,
S G Bodde, and M A Meyers, and J McKittrick
October 1954, Revista brasileira de malariologia e doencas tropicais. Publicacoes avulsas,
S G Bodde, and M A Meyers, and J McKittrick
March 2020, Journal of veterinary science,
Copied contents to your clipboard!