Creatures are funny, some species are quite skittish
as a species, others have very different behaviors
within the same species. Emus for example can run at the first sound of a drone but others will let you fly among them from just feet away as they peck away at the ground. Corellas are the only bird I've found that have consistent behavior anywhere I go, and that is to initially take flight but then, if you maintain a very slow constant speed and course, they will actually come alongside you and "escort" you through their territory either side of you up
very close. People say "aren't you scared they'll run into you?" and I say "have you ever seen them run into each other?"

Main things for any animal or bird is: 1. approach from downwind if you can and even better if the sun is directly behind the aircraft, 2. motor revs or sudden change of revs is your worst enemy, so best way to achieve both low noise and noise variation is to go really slow once you are getting close to them. 3. Further, I always say "use half your battery in the final approach". Of course this is an exaggeration but you get the idea. You can certainly use a faster setting to get to the animal but once within about 100 yards you're flying needs to be "delicate-city". This is where you need to be super patient and prepared to change cameras (and focus!) as you assess the situation, and they will all be different. Come in just about as slow as your drone will fly, and be prepared for that to take minutes not seconds. But do NOT suddenly change course or vary the revs. Instead of holding the joystick you should be very gently leaning on it from right at the bottom of the shaft. Practice that on stationary objects first and you'll be fine. I look forward to seeing what you come up with!