Don't let the man see ya'. Most places, disturbing wildlife with a drone can get you a nasty fine, and they write the regs pretty wide open for interpreting almost anything as "disturbing". Like if an elk looks up at the drone and then goes about it's business, the fact that it noticed the thing enough to change it's behavior and look could be a fine.
Has to be some exceptions, though. Because there were articles in the news a couple years back that Denver was using little ground and water skimming radio controlled things to chase off the geese in some of the parks. Probably by special permit, or maybe since that particular RC vehicle doesn't leave the ground so doesn't fall under FAA jurisdiction. Dunno.