If you plan to chase the Black-throated Gray Warbler at Noel Dorwart Park in Lancaster, may I please suggest you don't use playback as it is unnecessary. It's not very skittish or challenging to locate if you stay extra vigilant once the flock moves through (mostly loosely associating with blue-headed vireos and kinglets). We're very lucky to have this gorgeous male bird stick around for 10 days now and want to limit any additional stress as it hopefully finds its bearings and moves on to where it needs to be. I have seen the bird on eight days - only two did I have prolonged views, and another two I came up completely short. That's the thrill of the chase - just how things go sometimes. That said, feel free to move quietly off the trail for a better view as it moves through the underbrush. Thanks.