Winter Update #8: Mystery Bird

Peters Hill, Arnold Arboretum, 6:45am-7:30am
very clear, very cold

Help! Who is this mysterious bird?


His high warbling sound entranced me. I excerpted a little chunk to learn.
His version:


My version:

Just before that, I enjoyed this echo effect performance of three different tufted titmice on the hill:


And in between, a really gorgeous red sunrise. What does it mean? I'm thinking of the saying "Red skies at night, a sailor's delight/ Red skies in the morning, sailors take warning"?

A quick Google search reveals, courtesy of the Library of Congress, there is some truth to this saying, and has to do with light interacting with clouds, moisture or dust particles that might indicate either an approaching or departing storm system.

Also, I think a glowing red horizon (what I saw today) is not the same as a fully red sky. Still, the horizon is not so red every morning, and I enjoyed it!

**Update 2/19: the Mystery Bird has been identified as a house finch. Thank you Marc!!**