ML646207586

观察细节

This one has me a bit puzzled. Subjective observations include a more strutting/long-legged movement across the pavement; a more exaggerated head bobbing that didn't stay close to the straight-forward bobbing of a Rusty Bl., rather more "herky-jerky"- "side, forward, other side" sort of pattern to the walking. Vocalization lacked any squeaky tendencies expected of Rusty Bl. By themselves, not enough to go on, BUT.......... The photos consistently suggest a slightly shorter, THINNER, and STRAIGHTER bill than a Rusty Bl.; a subtler (non-breeding) pattern to the face and upper back WITHOUT rusty tones (more pale yellowish subtle highlights instead), the noticeably rusty tertial and secondary edgings of a Rusty Bl. are also ABSENT.