Eurasian Collared-Dove (Streptopelia decaocto) one of two observed near Sealing Cove.
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Eurasian Collared-Doves have only been reported in Alaska for a couple of years, and I think last summer was the first time any were reported in Sitka. However, their numbers do seem to be expanding, so it remains to be seen how common this bird becomes and in what seasons.
The recording above features a Eurasian Collared-Dove making the lower frequency (compared to other birds) cooing/hooting sound.