Great Britain MECHANICAL PROPERTIES OF CONTOUR FEATHERS

Young's moduli (E) in bending and extension were measured for selected contour feather shafts from the chicken (Gallus domesticus), turkey (Meleagris gallopavo), ring-necked pheasant (Phasianus colchicus) and herring gull (Larus argentatus). These were treated mechanically as tapering beams. In extension, E ranged from 45 to 181 MN m~8 and from 210 to 682 MN m~2 for the proximal and distal regions, respectively. Values obtained for the same regions in bending were from 5 to 24 MN m~2 and 457 to 1850 MN m~i. These results suggested that the cortex of the proximal region generally has a lower Young's modulus than the medulla, while for the distal region this is reversed. This was confirmed by further measurements on treated shafts. The observed systematic differences in the mechanical properties of the proximal and distal parts of contour feather shafts are consistent with their probable mechanical functions