Hi Kathy - You are likely seeing a Rufous Hummingbird. They look almost identical to an Allen's but are found in the Portland area. Allen's Hummingbirds are found mostly in California and a little bit in southern Oregon.
I'm not sure what the specific name of the hummingbird is but I have a couple that are exactly as you described that have been feeding in my yard for a couple of years now. and the throat is a spectacular red it's almost Electric. I've noticed it's very curious they always fly about 2 feet away from me the hover for a good 5 to 10 seconds and zoom around me it's really amazing
I had a clear view of the bird because the salvia it was dining on was less than 6 feet from where I was sitting. Its back was definitely green and not rufous.
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