Totally agree. I have so far been able to capture a few Sea Otters in my videos, They just seem to pop up near us. It's not like we are chasing them. It is the one reason I wish the Spark shot in 4K because the fairly wide angle lens means you need to be fairly close to a subject to really have any chance of filling the frame. With 4K you can crop and digitally zoom in a bit.
With the drones, I don't think its not going to be just the decibel levels but the pitch might matter as well. I am trying to get a better handle on how thee drones impact wildlife because I do spend a lot of times outdoors. I think stalking a moose with a DSLR camera and then spooking the moose is not any different than spooking them with a drone. I do think you will get slapped with a harassment charge though if you chase after it with the drone even though one could argue you could do that on foot as well and I have definitely seen examples of crowds of people chasing a bear or moose around trying to get better photos.