Black-and-white Warbler at San Elijo

I just found a Black-and-White Warbler on the nature center trail, behind the Water Means Life sign, where the American Bittern was seen. It appeared to be a male, and it was working the willows just above the brackish water. Maddeningly, fighting Mallards
spooked it deeper into the swampy interior before I could photograph it. Our SD Bird Festival group did not come over here today, but perhaps we can stop here tomorrow.