I saw this Great Blue Heron on Lake Washington.
https://500px.com/photo/173002653/a-heron-on-the-wing-by-jerry-cahill?ctx_page=1&from=user&user_id=3965034

I have a question, he has a red marking on his wing. I also have a picture
of one down at Nisqually who also has a red marking. Is this tagging or
could it be natural?

Thanks

Jerry
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