Yes to trembling - it weaves nicely into the stanza. Yes to putting two back in for the eyes - I'd liked the repetition and had regretted losing it. Also, you nailed what troubled me about the word "twin," though it had its appeal for variety's sake.
I'm trying out "two slim legs," which does give us additional useful information about birds, with some alliteration. OTOH, I now have two identical constructions for the two body parts, legs and eyes, in adjacent lines. I'm not quite sure how much that bothers me.
Thank you so much for helping me get this right.
Rereading. Interestingly, losing the definite article in that sentence (thank you!) may prepare room for the sudden question that immediately follows better than was previously the case. i don't know, but it marks a shift which the question continues.
Last edited by John Isbell; 08-31-2019 at 04:56 PM.