IS THERE ANY IMPORTANCE TO THE ANGLE THE BARB MAKES WITH THE SHAFT? dOES THIS ANGLE VARY AMONG DIFFERENT BIRDS AND DIFFERENT PARTS OF THE SAME BIRD…..WING FEATHER, TAIL FEATHER OR BODY FEATHER? i HAVE DONE SOME MEASUREMENTS ON FEATHERS FROM OUR AMAZON AND DID NOT FIND ANY FEATHER WITH AN ANGLE OF 45 DEGREES.
The importance of the angle the barb makes with the shaft is just how it effects the stability of the feather. That 45 degree angle mentioned is specific to the contour feathers and is a generalization not a perfect and strict rule. The other types of feathers we discussed (semiplume, down) will not have this same angle. As for if there are differences in the angle on the different parts of the bird it shouldn’t be too different from that 45 degree angle of the rachis to the barb for the contour feathers, whether it’s a contour feather of the wing or the tail or elsewhere. When you say you measured your amazons feathers to assess the angle, were you assessing the rachis to the barb? You will find that close to the calmus the angle is greater than 45 degrees and closer to the end the angle is less than 45 degrees. I checked some of Arroyo’s contour feathers and I was measuring about 45 degrees along the majority of the vane.
Dr. Stephanie Lamb
