We did a quick walk on the Marsh Discovery Trail n this a.m. to see if Dennis the Menace, the aggressive Red-winged Blackbird, was still defending his nesting area.

He is.  If you hear a male Red-winge Blackbird calling at you — typically a single note, repeated — don't dawdle. He is only doing his job.

(He is less aggressive if more than one person is there.)

(Thanks to Dennis Cheeseman for the photo; no relation.)