Nick had found the moth's cocoon on a Gray Birch in DeKorte Park earlier this year, and released the moth after it hatched. We think it hunkered down in a grassy section of the park so it could wait for dusk. (Thanks, Nick!)
Yesterday's post on this moth — and this year's Moth Night at DeKorte — can be found here.
You can tell male Polyphemus moths from females by the males' feathery antennae. An outside photo of the moth's awesome antennae follows.