A kind is any group that we have become familiar with to the extent that we have given it a name (And generally as a one word name or name we treat as one word: groundhog, bullfrog).
Finches are a kind; as are warblers. Birds are also a kind. But a cedar waxwing isn't a kind (though in some parts a waxwing is a kind, but not in Massachusetts because they aren't common.) Frogs are a kind; as are toads. Amphibians are also a kind. But leopard frogs aren't a kind.
The method for determining kinds is quizzing the locals. Simply ask "What kind of animals and plants you got around here?", and strike all the answers that aren't introduced with the phrase "We got us some". As in "We got us some grubs, and some worms; and kissin' bugs. Lots of kissin' bugs."
I hope this clears it up for all involved.
Happy new years, y'all.
You are now a million miles away from where you were in space-time when you started reading this sentence.