Sunday, April 29, 2018

Comparative Anatomy, Sparrow-Style


Day 198: Sparrow species aren't nearly as confusing as Warblers, but even so, they can be daunting for beginning birders. Take for example Golden-Crowned Sparrows (top) and White-Crowned Sparrows (bottom). Young Golden-Crowned birds often don't exhibit the distinctive yellow patch on the tops of their heads until they've gone through their first moult. A novice birder, seeing only a white stripe might assume that a young Golden-Crowned was a White-Crowned, but closer observation of the head will give a second clue. White-Crowned Sparrows also have a white stripe above the eye. The top stripe and the eye band intersect on the back of the head, giving the bird the appearance of wearing a bicycle helmet. Golden-Crowned has only the single stripe, and even if the yellow feathers have not emerged, this distinguishes them from White-Crowned quite readily.

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