It reminded me of this jargon topic, but I honestly can’t think of anything but “obs” being an observation.
Lifer is a taxon seen or recorded for the first time by this user (depends on personal view on that)
Herper is short from herpetologist, on iNat likely not a professional, but one deeply interested in reptiles and/or amphibians.
Birbs is a general term for most birds. There are lots of phrases for certain birbs, such as Cobra Chicken for Canada Goose. Chikken or chicken is used for a lot of birds. See https://www.facebook.com/groups/birdmisid (you may need to [gasp] join!).
Never understood the “birb” thing. It isn’t short for bird and no easier to pronounce so where did it come from and why? Maybe it’s a Facebook thing and I wouldn’t be in the know if so.
The word began, as near as anyone can tell, when the absurdist Twitter account BirdsRightsActivist tweeted the single word “Birb,” out on November 2012; two years later, it had multiple entries in Urban Dictionary and a dedicated reddit forum.
There are other similarly wonky misspellings such as smol, snek, and chonky. It’s not meant to be an abbreviation; it’s meant to be slightly off-kilter.
BTW, there’s a book out titled Because Internet that covers how the Internet shapes language. I haven’t read it myself yet, but it sounds like a good read.