Field estimates of body drag coefficient on the basis of dives in passerine birds
During forward flight, a bird's body generates drag that tends to decelerate its speed. By flapping its wings, or by converting potential energy into work if gliding, the bird produces both lift and thrust to balance the pull of gravity and drag. In flight mechanics, a dimensionless number, the body drag coefficient (C-D,C-par), describes the magnitude of the drag caused by the body. The drag coef
