I think most of these refer more to hunting or food-gathering than scientific investigation, though. “Bird” should really be on the list (there’s a book called The Verb “To Bird”).
I don’t think it’s official, but maybe it becomes if enough people are using it. My Spanish friend use “bicheando” from bicho. So I’ve decided to call my activity of animal watching beasting. ;-)
If I’m specifically focusing on birds and keeping an eBird list, I call it birding. If I’m looking at everything and taking photos for use on iNaturalist, I call it iNaturalizing.
I don’t know how official it is but someone near and dear to me refers to my naturalist activities, when pursued with diligence and stamina, as goofing off.
Lichenizing for looking for lichens and botanizing for looking for plants are terms I have heard frequently within groups dedicated to those activities as well.
Anyone notice that this is very similar to the Word for Nature Trip topic? I know this one is a bit more focused, but it’s something to keep in mind. Maybe they should be merged?