While burning some time before my flight out of St. Louis this morning, I visited Busch CA. Near the visitor center, I heard a chickadee that was reminiscent of my days in Michigan. I saw the bird although briefly, but everything seemed to fit Black-capped Chickadee. The call, "hey fee-bay" or "Hey Sweetie" . . . not the Carolina's call of, "Hey sweetie hey" was what I heard.
I remember last year when visiting during one of the ASM outings someone saying that the St. Louis area has chickadees that can vocalize either species' call.
I feel fairly confident that this was a BCCH.
I also struck out on the Blue Grosbeak Trail for the Northern Shrike, but by that time, I needed to be getting to the airport. If someone happens to see it again before Wednesday please post.