Last year in March, we had several opportunities to hear and see the NSWO at Chatfield State Park, and I am fairly certain that this was the call of the NSWO. Could have been a NOPO, but the hoot was evenly spaced and sure sounded like what we heard last year.
Not putting it in eBird, but we will be keeping our ears (and perhaps our bedroom window) open, in hopes of hearing it again.
Good birding!
Tom & Debbie Behnfield
Lakewood, CO
behnfield!q.com