Take your shots of the waterfalls earlier in the day or late in the day , you’ll have a easier time catching an awesome pic ... happy days 👍🏻

I would have no used the auto ISO for starters . I would have set the iso at 1000 -1250 app 7 or 8 and shutter about 800 -1000 . Because the bird is just cruising .. not much movement . A 100-400 lens would also help :) happy birding

I think you’ll always get blurry photos with a iso over 1250 your 6400 iso is a problem, it causes grain ...if you shoot manually you can set your shutter ( does not have to be very high for sitting subjects) and aperture setting accordingly to light as well as ISO .learn about SHUTTER APERTURE ISO. 😊👍🏻Happy shooting
Cheers

Easier is not always better.... learning what ISO APERTURE and SHUTTER speed setting do will make you a better photographer !