What distinguishing field characteristic separates the *gambelii* subspecies from coastal groups like *pugetensis*?
Answer
Differences in the crown stripe pattern, specifically the ratio of white to black stripes.
Tracking subspecies variation relies on subtle but consistent visual cues. While the text notes differences in overall grayness of the face, a key field marker for differentiation, especially when contrasting long-distance migrants like *gambelii* with shorter-distance coastal types like *pugetensis*, is the crown pattern itself. Observers can sometimes determine the likely origin or migration status of a bird by analyzing the crown stripe—specifically, observing how much white is present relative to the adjacent black stripes on the head.
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