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In page Red-winged blackbird:

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There are a number of subspecies, some of doubtful status, which are mostly quite similar in appearance. However, there are two isolated populations of bicolored blackbirds that are quite distinctive: A. p. californicus of California and A. p. gubernator of central Mexico. The taxonomy of these forms is little understood, and the relationships between these two populations and between them and red-winged blackbirds is still unclear.[5] Despite the similar names, the red-winged blackbird is in a different family from the European redwing and the Old World common blackbird, which are thrushes (Turdidae).[1]