Which Is It?

Continuing to talk about Hummingbirds, here is a photo of a Hummingbird at our feeder that points out an interesting problem.  Rufous Hummingbird males are easily recognized by their overall coopery rufous coloring.  Allen’s Hummingbird males have the rufous coloring on their fronts and sides, but their backs are green.  However, and here is where it gets complicated, up to 5% of Rufous males can have a green back.  No Allen’s Hummingbirds have been reported to eBird here in Douglas County, but they have been reported in Coos County, the next county to the south.  So, which is it, a stray Allen’s or an unusual Rufous?