Rhc. Bonser, COMPARATIVE MECHANICS OF BILL, CLAW, AND FEATHER KERATIN IN THE COMMON-STARLING STURNUS-VULGARIS, Journal of avian biology, 27(2), 1996, pp. 175-177
The Vickers microhardness of non-melanic keratin was measured from the
bills, claws and outer primaries of Common Starlings Sturnus vulgaris
. Highly significant differences in hardness were found between all th
ree keratin types. Bill keratin was the hardest and feather keratin th
e least hard; the relative molecular weight of the different keratin t
ypes may explain these differences. Indentation hardness can be used a
s a measure of the competence of a material to resist abrasive wear so
it is likely that the three keratin types differ in their competence
at resisting abrasive wear.