American Bittern vocalizing at Goose Pond

My son and I stalked some bitterns at GP8. We eventually tracked one down out in a more open area. We didn't harass them. We just moved real slow and took plenty of time. When we left he was still calling as part of a trio and wasn't flushed. (If you have the volume up high enough you can hear him and the other sounds of the grassy marsh. There are no loud startling sounds to worry about.)