Maybe genera and also species. The trick not to be confused by language's sometimes referring to different things either ambiguously or with the same word.
Edit: An arrow flies, a bird flies, a squirrel flies, a jet plane flies. We all understand what is meant in each case, but it would be not-so-easy to make clear just exactly what the understanding of "flies" is with any reasonable rigor.

What is the definition of a universal that you're using?

I've looked into this since it seems like it would come up at the intersection of process philosophy and realism. People have certainly proposed actions as universals, but it has really not garnered much attention from what I've seen.

Part of the problem is that the universal is called on to explain "what stays the same" across various instances but then a processual universal must in some way incorporate change within itself.

but then a processual universal must.... — Count Timothy von Icarus

I want to credit yours a great answer, but need a little expansion. Not sure what a processual universal might be. I can imagine the idea of a universal tree or horse - not without some problems. That is, in some sense these universals ought to be things of some kind - presumably other than just ideas, which is what I think they all are. But of running or jumping? Or, how does a process become a thing? Or if not a thing and not just an idea, then what?

Are actions in general (such as buying, walking, flying etc.) considered universals? — SEP lineolata

If I understand your question correctly, I suppose so sub specie aeternitatis (or from a 4-d pov) ...

I see universals as meaning only ONE kind of thing. There are different types of 'walking' but not different types of 'the number one'.

If you cannot ask "what kind?" it is a universal.

Are actions in general (such as buying, walking, flying etc.) considered universals? — SEP lineolata

Hmm. My first thought is that no, they are particulars but that the idea of any action is a universal. But good question.